Bölümler
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Summary: This is The Feathered Desert’s final episode and Kiersten and Cheryl are talking about their recommendations for future listening.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
List of podcasts discussed:
BirdNote Daliy
Threatened
The Science of Birds
Songbirding
The American Birding Podcast
The Warblers
Bring Back Birds
Ten Things I Like About…
All of these can be found on all major podcast outlets
Further recommendations involving more animals than birds:
Just the Zoo of Us, by Ellen and Christian Weatherford
Going Wild with Dr. Rae Wynn-Grant
Transcript
Kiersten: Intro: Welcome to the Feathered Desert. This is our final episode, so it’s a bittersweet moment for us both. We’re sad to go, but we’re so happy that we were able to create this podcast that brought enjoyment and education to our listeners. We won’t leave you high and dry with nothing to listen to, though. In this episode we’ll recommend a few other podcasts that we enjoy listening to and we hope you’ll enjoy, as well.
Cheryl: We’re going to start off with one of our favorites, both Kiersten and I listen to this one and we think you’ll love it too. BirdNote Daily is a three-minute podcast that posts daily episodes. This podcast is all about what’s happening in the bird world. New discoveries, how birds impact our mental health, female bird song, great bird dads. These are only some of the great topics you can hear on this show. It’s actually inspired several of our own episodes.
Kiersten: BirdNote also produces another podcast called Threatened. This series has longer episodes and talk about threatened species of birds and everything related to that species. They talk about the research being done to help their survival. They discuss why they are threatened in the first place. It’s a fascinating podcast that shows how birds and people are linked.
Cheryl: Another of my favorites is The Science of Birds. This one is hosted by a gentleman that loves his birds. He writes episodes about birds of all kinds and reveals the fascinating things that make them special.
Kiersten: I just discovered this next a few weeks ago and I absolutely love it! Songbirding takes you on birding outings with the host. He records himself hiking and birding by ear in various natural spaces. I know it sounds boring and weird but he points out the bird’s song when he hears them and tells you what species they are. It’s actually really cool and very relaxing.
Cheryl: The American Birding Podcast keeps you informed on everything that is happening in the birding world. This one focuses a bit more on the art of birding but it does have some pretty interesting interviews with prominent bird personalities and authors and scientists.
Kiersten: The Warblers is a podcast by Birds Canada, a non-profit organization that works to protect birds and their habitat in Canada. They do talk about birds that are not often found in the Southwest but it’s all fascinating information about birds. It’s a great podcast to help you expand your knowledge of bird species.
Cheryl: Bring Back Birds is another podcast from BirdNote that talks about the declining bird populations, but doesn’t leave you crying. It highlights programs of conservation that make the future of birds look hopeful.
Kiersten: I can’t end this episode without a shameless plug for my new podcast called Ten Things I Like About… For those of you that can’t get enough of me, check out this podcast. It’s a ten-minute, ten-episode podcast about unknown or misunderstood creature in nature. This one doesn’t focus specifically on birds but there are bird series included. And Cheryl joins me for some episodes and will probably join me for more in the future!
Well, that’s all for The Feathered Desert, listeners. We are signing off for the last time. We hope you’ve enjoyed our show as much as we enjoyed making it.
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Summary: Finches visit Arizona in the winter. Join Cheryl and Kiersten to find out which finches may visit us in winter.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“Arizona’s Winter Finches,” by Charles Babbitt The Cactus Wren-Dition Winter 2023
Transcript
Cheryl-Intro
Some finch species are highly prone to irruptions-which are occasions when large numbers of birds take flight and regularly move hundreds of miles beyond their normal winter ranges in response to food scarcity especially cone and seed crop failures. Kiersten and I did a podcast last year about irruption in the bird world so check out that podcast to get more information.
In the winter of 2022-2023 was such a situation when Evening Grosbeaks, Cassin’s Finches, Red Crossbills, Pine Siskins, and Lawernce Goldfinches were reported in large, unprecedented numbers at many locations around the state of Arizona. These are the nomadic winter finches of Arizona.
Kiersten-Red Crossbills
The Red Crossbills are the oddest of the group. When you get a close look at their bill you will see what looks like a deformed beak with the lower mandible crossing under the upper mandible. This allows the crossbill o pry open tightly closed cones to extract the seeds, an evolutionary adaption that gives them access to a unique food source. Red Crossbills are resident breeders in much of Arizona’s upper elevation forests. In flight years, however, irruptions can bring roving flocks from out of the state swelling numbers in mountainous areas and sometimes bringing these boreal invaders into the lowlands such as the Phoenix Valley.
Cheryl-Pine Siskins
Pine Siskins are one of the smaller winter finches often confused with the House finch. These little birds are year-round residents in Arizona’s high country they are famous for their periodic irruptions. Movements are irregular and sporadic with birds being quite common some years and entirely absent other years.
Pine Siskins have sharp narrow bills they use to extract seeds from the cones of a variety of conifers. In winter, flocks are often seen at feeders, with the Lesser Goldfinch and the House finch, or in weedy fields. These birds are quite personable and a person can get quite close to them before they will take flight. Pine Siskins are recognized by their steaky breasts and the bright yellow markings on their wings. In flight they show a distinctive yellow wing stripe.
Kiersten-Evening Grosbeaks
Of the winter finches, Evening Grosbeaks are the most striking. These stocky birds have evolved massive cream-colored beaks which are unmistakable and which are used like nutcrackers to feed on a variety of large seeds, catkins and even small fruit pits. In northern Arizona these birds might be seen feeding in winter on Russian olive fruits and juniper berries.
Male Evening Grosbeaks are yellow and black with a distinct yellow forehead and eye brow and large white patches. Females are mostly gray with a yellowish-green collar and black and white wing markings.
In Arizona Evening Grosbeaks breed very locally in the high country. In the winter they form large noisy flocks. Like the other winter finches Evening Grosbeaks have irruptive years, and when they do these birds delight bird watchers and the bird feeding hobbyists by crowded around seed feeders to eat sunflower seeds.
Cheryl-Cassin’s Finch
Cassin’s Finches are restricted to northern Arizona mostly the regions of the Kaibab Plateau and higher elevations of the Hopi and Navajo tribal lands. In the summer you are most likely to see them in pine and mixed conifer forests on the North Rim of the Grand Canyon. Males are easily recognized by their bright raspberry red caps and rosy tinged faces and breasts. Females are plainer with streaked breasts.
Cassin’s finches are migratory and irruptive with great variability in distribution and abundance. In some winters they can be quite common and be found in the low foothills of the phoenix Valley.
When they are around, they visit finch feeders, often mixing with Pine Siskins, and other local finches. As spring warms the foothills you can spot these hardy finches gathered in trees where they sing incessantly.
Kiersten-Lawrence’s Goldfinches
Some years Arizona is visited by winter finches not by the north but from the west. These are Lawrence’s goldfinches, colorful birds whose breeding range is mostly the coastal ranges and foothills of the Sierra Nevada of California. There these birds occupy a variety of habitats including dry foothills, open woodlands and adjacent grasslands. In sporadic and unpredictable flight years some depart their breeding range, heading eastward in the southern part of Arizona.
Lawrence’s Goldfinches are a soft gray color with gold markings on the wings and chest. Males have black faces with contrasting pink bills while females tend to be less colorful.
Lawrence Goldfinches are seed eaters. As with the other winter finches, seed crop failures due to drought or even more recently, massive wildfires are probably the principal driver of this birds’ periodic movements into Arizona.
Cheryl-Closing
The question has been asked if scientists will ever be able to predict winter finch irruptions. Maybe. East of the Mississippi River, with the data compiled and the network of observers, the bird world enthusiasts attempt predictions of which winter finch will have a flight year. But in the west and especially the southwest with our mountainous terrain, diverse and widely separated habitats, and the lack of a network of observers, predictions are unlikely. Truly the unpredictability of the Arizona’s winter finches is what keeps the mystery and excitement in the sightings of these birds when they appear.
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Eksik bölüm mü var?
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Summary: Bird names are changing in 2024. Join Kiersten and Cheryl as they talk about a controversial decision made about bird names.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“American Ornithological Society Will Change the English Names of Bird Species Named After People,” AOS Leadrership, https://americanornithology.org
“These American birds and dozens more will be renamed, to remove human monikers,” by Nell Greenfield-Boyce. NPR Morning Edition, November 1, 2023.
https://www.npr.org
Transcript
Kiersten: Intro: Quoting the bard, William Shakespeare “A rose by any other name would smell as sweet.” I hope all you birders out there believe this quote to be true, because some changes are a’comin where common bird names are concerned. The American Ornithological Society has decided to change the English names of bird species named after people.
Cheryl: In November of 2023 the AOS announced that birds named after people would be renamed. Birds such as Anna’s Hummingbird, Bullock’s Oriole, Abert’s Towhee, Gambel’s Quail and Bewick’s Wren will all be renamed. Scientists will form a multi-disciplinary committee that will seek public input when they begin renaming the birds. They will focus on birds that are in the AOS’s jurisdiction which is the United States and Canada. Beginning in 2024, they will start with 70 to 80 species.
Kiersten: Why are they doing this? Quoting Dr. Collen Handel, president of the American Ornithological Society and a research wildlife biologist with the U.S. Geological Survey in Alaska, “There is power in a name, and some English bird names have associations with the past that continue to be exclusionary and harmful today. We need a much more inclusive and engaging scientific process that focusses attention on the unique features and beauty of the birds themselves.”
For example, in 2020 McGown’s Longspur, a small prairie songbird from the Great Plains, was renamed to the thick-billed Longspur. This name focuses on the characteristics of the bird instead of using the birds to honor a human being. I like this thought process. This is what the scientists are going to do with all those names.
Cheryl: By doing this, the AOS is admitting that the previous process for naming birds comtained some bias. There are three guidelines they will be using for the renaming process and for future newly discovered bird species.
The AOS commits to changing all English-language names of birds within its geographic jurisdiction that are named directly after people, along with other names deemed offensive and exclusionary, focusing first on those species that occur primarily within the U.S. or Canada.Kiersten: The second guideline:
The AOS commits to establishing a new committee to oversee the assignment of all English common names for species within the AOS’s jurisdiction: this committee will broaden participation by including a diverse representation of individuals with expertise in the social sciences, communications, ornithology, and taxonomy.Within the scientific community, AOS will include a broader representation of scientists this go around, instead of just a bunch of old white guys.
Cheryl: The third guideline:
The AOS commits to actively involving the public in the process of selecting new English bird names.So, instead of just involving scientists on the naming process, the AOS will reach out to the communities where these birds are found as ask for comments and suggestions.
Kiersten: Quoting Dr. Judith Scarl, AOS Executive Director and CEO, “As scientists, we work to eliminate bias in science. But there has been historic bias in how birds are named, and who might have a bird named in their honor. Exclusionary naming conventions developed in the 1800s, clouded by racism and misogyny, don’t work for us today, and the time has come for us to transform this process and redirect the focus to the birds, where it belongs.”
Cheryl: We know that there will be a lot of push back from birders who have been birding for many years, but this is a necessary step to opening up birding to everyone. Because birding is for everyone. Ken Kaufman, author of many widely used bird ID guides, weighed in on this decision in a recent NPR article. He’s been using these names for the last 60 years and was initially upset by the decision because he knows some of the people these birds are named after, but he’s come around to the idea. He was quoted as saying, “It’s an exciting opportunity to give these birds names that celebrate them, rather than some person in the past.”
Kiersten: I think Ken’s quote about sums it up. Remember that the only thing changing here is the name of the bird, they are still as beautiful and as fun to watch regardless of what call them.
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Summary: Now that you know what MOTUS is and what it does, let’s talk about how is helps Arizona birds. Join Cheryl and Kiersten to find out how MOTUS is helping some Arizona birds.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“Desert Deliverance”, by Margo Rosenbaum, Audubon Magazine Fall 2023, pg 18-19
“Home Away From Home”, by Daniel Grossman, Audubon Magazine Fall 2022, pg 30-35
“The Mysterious Decline of the American Kestrel,” by Jillian Mock, Audubon Magazine Spring 2023, pg 20-27
“Keeping Up with the Grosbeaks,” by Zoe Grueskin, Audubon Magazine Winter 2023, pg 15
Transcript
Cheryl-Intro:
Recently, we posted a podcast about MOTUS. What it is-radio tracking system-more towers being placed in Arizona, one possibly at the Gilbert Riparian Water Ranch. I wanted to revisit this because I found actual research studies using MOTUS that has an impact on Arizona birds. It is exciting to see the impacts of this new technology and how it is advancing research in bird studies.
Keirsten: Purple Martins
If you have lived on the east coast or in the mid-west of U.S. you have seen Purple Martins, and the colonial-style bird houses that they like to nest in. A little back story about this bird, Purple Martins are insectivorous (insect eaters) which has made them vulnerable to the pesticides we use on our yards. So, their numbers were really in decline here in the U.S. until citizen science got involved. People who enjoyed seeing the birds and understood their importance to local insect control started placing the correct nest boxes these birds like. These citizen scientists monitored the boxes, eliminated pesticide use on their properties, kept cats indoors etc.
Over time the populations of Purple Martins bounced back in the Untied States. So why are we talking about them…because their numbers are still in decline, and scientists don’t really know why. Purple Martins have been studied extensively In North America; scientific knowledge tapers off when they fly south. Just where do they go, Wat routes they take, and what critical habitat lies Along the way remain largely a mystery. The marathon journeys these birds undertake every year compounds the risk to their survival.
Arizona has its own sub-species of Purple Martins that prefer to nest in Saguaro cacti in the southern part of our state. Arizona’s Purple Martins spend the winter where? They take a similar marathon journey as those who summer east of the Mississippi River.
Cheryl: Get to the point-Brazil.
Just off a slice of land sitting mid-stream in Brazil’s Rio Negro, is an island locally known as Ilha do Comaru, every year this island is submerged in March and only the tree tops poke above the surface. There in those treetops are Purple Martins. Now, Motus helped to locate this tiny island of 12 acres (slightly larger than Yankee Stadium). How you ask? Back in the U.S., scientists with the help of volunteers tagged nesting Purple Martins (adults and fledglings) with radio tags that will ping a receiver, that by chance was placed near this island.
Scientists looked at the MOTUS network tracking and thought huh? Where is that? It turns out that MOTUS revealed to scientists a space that is host to a concentration of roughly 250,000 birds between February and April, it’s one of the largest Purple Martin roost ever discovered. Its significance isn’t just its size, however, but also the pivotal role the roost may play in the bird’s long-distance migration. Comaru could be the staging ground, or launch pad, for many of the 9.3 million Purple Martins that funnel through from South to North America.
Scientists are tagging Purple Martins on this tiny island, so they can trace birds coming and going to see where these birds’ journey to breed. Some head to Arizona, and some head towards the east coast of the U.S. This is important to Arizona Purple Martins because our sub-species like to nest in Saguaros that are 40 ft high. It is easier for everyone if the tagging is done on this tiny island.
Scientists are excited to trace the movements of these birds to figure out what they’re eating and analyze whether they’ve been contaminated by pesticides and other pollutants, we can learn something about how they’re doing in Brazil.
Scientists feel that by taking a closer look at the birds onto this small isle, they hope to glean insights that can help secure the future of the entire species, and any discoveries they make will help uncover what’s behind the decline of other songbirds, especially other aerial insectivores.
Keirsten: The American Kestrel
Arizona hosts the American Kestrel all year long. It just moves within the state. This bird is on the decline here due to loss of habitat, pesticide use, and the increase in population of Cooper’s Hawks, to name a few challenges this small falcon must face daily. Scientists are racing to understand why this bird is continuing to disappear from our skies.
Let’s move to Texas where there is a project that outfits kestrels with radio trackers to glean how they move on their wintering grounds and where they breed come spring. The exact paths kestrels take and the ultimate winter destinations for many populations are mysteries. Their smaller scale movements are also an enigma: researcher Maddy Kaleta stated in an article for Audubon Society “We know kestrels need open space, but we don’t know enough about where they prefer to hunt, how big their territories are, or what they do when their preferred habitat disappears. Kestrels that spend one winter hunting in a field may return to find it has disappeared under concrete and new shopping attractions the next winter. MOTUS is helping answer these questions.
Data from this study indicates sharpest kestrel declines are in the East. For the birds that show up in the nest boxes placed by citizen scientists, their success rates are very high. A single kestrel pair fledges three to four chicks on average. The puzzling problem is that they are not showing up.
In the west, kestrels are showing up, but they are breeding weeks earlier than they did in the 1990’s and scientists discovered that farmers are taking advantage of significantly warmer winters by planting crops earlier to avoid the hotter summers. The change in planting draws insects and rodents which is a bounty for the kestrels, and kestrels are taking advantage of this change.
All this data collected will help Arizona protect the American Kestrels that choose Arizona as their home.
Cheryl: Evening Grosbeaks
This beautiful bird winters here in the lower part of Arizona on occasion but spends most of its time up in Arizona’s boreal forests. But since 1970, the once common species has sharply declined in the EAST, making irruptions less frequent and grosbeak visits increasingly rare.
Scientists started out with a small number of tagged birds aiming to discover where these birds go in spring. Then with numbers declining they scaled up their tagging and tracking to over 200 birds so far. Using radio and satellite tags, scientists plan to expand across more of the species U.S. Range because Evening Grosbeakshave unpredictable roving patterns and this makes it vital and challenging to understand their movements. These birds are somewhat secretive and breed in remote areas, so trying to find where they’re nesting isn’t easy. So once a bird is tagged in winter scientists can follow its journey. This data collected from MOTUS will help answer questions and could reveal bottlenecks or pressure points for the species and clues about what’s driving the decline.
Researchers have found evidence of climate change is stressing spruce and fir forests where these birds like to nest, and diseases such as conjunctivitis, West Nile virus, or salmonella infections may all play into Evening Grosbeaks and their decline. Tagging and tracking birds has highlighted the vulnerability of birds and window strikes.
All this data, even if it is collected on the East coast will help Arizona fast track efforts to protect our population of Evening Grosbeaks with MOTUS’ help.
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Summary: What is MOTUS? It’s the next step in bird migration science. Join Cheryl and Kiersten to find out how this is putting the Phoenix Valley on the map!
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
MOTUS: https://motus.org
“What is MOTUS?” by Rebecca Stephenson. Desert Rivers Audubon Magazine, Winter 2023.
As of the recording of this podcast, we have not been able to find a link with volunteer information for MOTUS but the article on this site tells you how to reach out if you’re interested: https://sonoranjv.org/building-capacity-motus/
Transcript
Cheryl: Intro
It has been a constant challenge for scientists to study migrating birds. They do not stay in one place for long. Where these birds go, stop over, and end up on their journeys? What scientists would love to have available to them s a way to fly along with these birds so they have a complete picture of how these birds live. This complete picture is what an amazing wildlife tracking system called Motus does.
Kiersten: What exactly is Motus?
Well, it was started by the non-profit Birds Canada in 2014. Motus is Latin for movement and the system seeks to track the precise travels of birds and other winged creatures, like bats, bees, and monarch butterflies through digital radio telemetry. This is how it works; birds and other winged animals are carefully fitted with a small, lightweight transmitter, called a nanotag. These nanotags are attached using minimalistic harnessing or glue. Then the animals are released. There is no need to recapture them to obtain the data collected, instead the transmitter on the bird sends back a unique ping out into the atmosphere on a shared radio frequency. The pings transmit in a 12-mile radius around the bird as it goes about its life. The motus tower stations tuned to this frequency then picks up the pings and relays the data to the database headquarters in Canada, where it is processed, analyzed, and shared with researchers.
Cheryl:
When tracking wildlife with automated radio telemetry over vast distances, the challenge of deploying enough receivers to detect the tracking information grows exponentially. To be able to share this information between researchers MOTUS remedies that so basically everyone is sharing the same data. This greatly expands the potential to track birds with high temporal and geographic precision over great distances which put Motus so far ahead of the more commonly used tracking methods. These methods Kiersten and I have talked about in one of our migration podcasts. There’s the GPS or geolocator tracking device, this device stores data over time or as you may have seen on TV a person following an animal with a handheld receiver. In order for stored data to be useful it has to be recovered. This involves recapturing the animal/bird and removing it. A lot of variables at play, and long hours for the researchers.
Like anything in life things don’t always go as planned even with Motus. There are the transmitters, the large ones are solar-powered, this eliminates the need to change batteries, but the smaller ones, these fit on small songbirds, hummingbirds, bees, and butterflies must rely on battery power. Once the battery goes dead the transmitting of data stops, there’s also nature getting in the way like a bird dies, or the transmitter falls off.
Kiersten: Then there are the tower stations.
The tower stations for Motus are just small antennae connected to a receiver and power supply. Each station detects pings from any transmitter within a nine-mile radius of it, in optimal conditions. As impressive as that may be, it is still limiting as far as being a wide-ranging migration tool. To effectively track wildlife in real time requires a lot of stations. The stations have to be installed, then diligently maintained, which can be a difficult job considering that they are often placed in remote locations, subjected to environmental havoc such as lighting strikes, or sometimes rendered in operable by an animal’s teeth.
But it is all so worth it, because through the data collected by Motus scientists get a complete picture of a bird’s migration journey: where it goes, how fast it travels, where it stops to rest and for how long, and where it ends up. This information can help scientists to know how birds migrate, such as what areas they rly on during stopovers, how long they stay at each spot, when and where they begin their journey, and where it ends. This information also, expands on the nuances of migration and what specific populations do.
As of 2023, over 1,500 Motus tower stations have been deployed in a total of 31 countries, including Canada and the United States. Mexico, Australia, the United Kingdom, and Chile.
Cheryl: Motus is growing.
Even though Motus is still in its infancy, it is growing rapidly through the international conservation communities. Motus has shed light on the lives of endangered birds such as the Pacific Red Knot, Snowy Plover, Tricolored Blackbird, and grassland birds, and the mysterious Lewis Woodpecker.
A third of migrating bird species in North America are on the verge of extinction. That is alarming, but with this powerful conservation tool we can learn about the potential problems birds face at both ends of their full annual range. Motus collects the kind of data that ells biologists precisely how each and every bird survives year to year-what waterways, or other landscapes birds are using to make their survival happen. Motus also shows us what areas birds are not using or avoiding. This data will help researchers to know what areas need to be protected to help birds survive and thrive.
Kiersten: Arizona on the map.
As of 2023, Arizona only had a modest handful of three Motus tower stations, including one attached to a defunct windmill-now that is changing. There are plans to currently build more towers, with the possibility of one being placed at the Gilbert Riparian Preserve and outfitting more birds with transmitters. Arizona had its first Motus Tag application certification training course to teach volunteers how to safely handle and tag birds in February of 2023. There are plans to host many more in the coming months. Running Motus takes volunteers, and experts working together.
Cheryl: Closing
So, the more volunteers, the more transmitters that are airborne, the more transmitters that get deployed, and the more towers there are to move the data the bigger, and more complete the picture of bird migration patterns will be. As the saying goes the more the merrier… it’s true with Motus.
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Summary: How often do you look for female birds? Join Kiersten and Cheryl as they talk about Female Bird Day and why it’s important.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
Kenn Kaufman Article: https://www.audubon.org/news.i-became-better-birder-when-i-stopped-focusing-males
Female Bird Day Blog: https://femalebirdday.wordpress.com
Transcript
Kiersten: Intro: This episode is about Female Bird Day. In 2024 Female Bird Day will be May 25-27. We going to talk about why this is a day. Why do we need a Female Bird Day.
Cheryl: In 2018, Kenn Kaufman wrote an article for Audubon Magazine titled, “I Became a Better Birder When I Stopped Focusing on the Males.” For those of you who don’t know who Kenn Kaufman is, he is the author of some of the most well-known Bird ID guides used in North America. Quoting from his article, Kenn says “…an unconscious bias against female birds is widespread in birding.” He is correct! If you look at the names of birds that describe what sexually dimorphic birds look like, they always describe the male’s coloration not the female. For example, the Ruby-throated Hummingbird describes the red-colored gular feathers that the male possesses. The Cinnamon Teal, a species of duck, describes the male’s coloration during breeding season. Red-winged Blackbirds describes the wing bars seen on adult males during breeding season.
Furthermore, the names of birds used to honor well-known ornithologists is always named after a man. Audubon’s Warbler, Harris’s Hawk, Abert’s Towhee, Allen’s Hummingbird. They are all named after men. You can count on one hand how many of the 10,000 identified bird species in the world are named after women. Lucy’s Warbler is just one example and this bird was named after the daughter of a well-known male ornithologist.
Kiersten: It doesn’t stop with just the names of birds. We all but ignore the fact that females also sing. For many years, most of the history of ornithology actually, male bird songs have been the only ones studied and recorded, even after we discovered that females sing. The first few scientists that discovered this wrote it off as just an anomaly and didn’t put it in any reports. In 2014, a study focusing on avian song worldwide revealed that female bird song is both common and critical in evolution. 2014! We’ve been studying birds since the written word was developed.
A study published in 2019 recorded two female Cerulean Warblers singing a different song than the males. Of course, this is also one of those birds that is named for the male’s blue color. The scientists that heard the females sing were surprised to say the least. But they documented their findings which is one step toward us truly understanding the purpose of bird song. Since we have based all our hypotheses and theories on only half the population, could we have misinterpreted why birds sing?
Cheryl: Female Bird Day is a challenge started by five amazing women interested in birds. Three work for various levels of Audubon: Brooke Bateman, Stephanie Beilke, and Martha Harbison. Joanna Wu is another ornithologist with UCLA and Purbita Saha is the editor of Popular Science. During the Covid lockdown days, these women issued a challenge to birders all over North America to focus on female birds. This challenge continues this year. In 2024, May 25 through May 27 is Female Bird Day. So, all you birders out there mark your calendars and focus on female bird identification and bird song on these days. To report your findings, you can go to femalebirdday.wordpress.com and fill out the google forms that will be delivered directly to The Galbatross Project.
Kiersten: And keep it up all year long. Don’t just focus on the female birds on those days only. Do it all year long. In his Audubon article Kenn Kaufman states that when he included female birds in his searching repertoire he became a better birder and, quoting directly, “…there’s a whole world of birds out there, and it just wouldn’t make sense to ignore half of them.”
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Summary: Why do birds flick their tails? Join Kiersten and Cheryl as they talk about some of the reasons birds may flick their tails.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“Why Do Birds Flick Their Tails?” Bird Note, June 13, 2023
“Why Do Phoebes Pump Their Tails?” David Sibley, https://sibleyguides.com
“Tail Movements in Birds – Current Evidence and New Concepts,” by Christoph Randler. Ornithological Science 15: 1-14 (2016).
Transcript
Kiersten: Welcome to the Feathered Desert. Have you ever been bird watching and wondered why that bird is flicking its tail? I know I have, so today we’re going to discover why birds flick their tails.
Cheryl: Let’s start off by defining a tail flick. Because, believe it or not, there is an actual definition of a tail flick. Tail flicking refers to the vertical up and down movement of the tail. Tail flashing is the horizontal movement of the tail that often includes spreading of the tail feathers. These tail movements are described with several different names such as tail flick, tail wag, tail flash, tail pump, and tail up display. So, I’m not sure how much our definition REALLY matters.
Researchers believe that most intentional tail movement has to do with communication. That can mean communication to other birds of the same species, or communication to a predator, or to a prey item.
Kiersten: There are several hypotheses about intra species communication. That is communication between the same species of bird.
One hypothesis is communication between possible mates during breeding season. Does tail flicking help find a mate? If you’re the common Moorhen, it just might. The Common Moorhen, also known as the Waterhen and Swamp Chicken, is a member of the Rail family. They are commonly found in wetland areas all around the world. Unlike most species of birds, female moorhens are the ones that fight for the attention of a mate. Tail flicking plays a role in her acquiring a mate. Females will flick their tail to attract a mate’s attention. Researchers found that females with better body condition flicked their tails faster than those with less fat store.
Cheryl: Some birds may be using their tail flicks to coordinate flock behavior. Mallards, a duck found all over the world, but native to North and South America, increase tail flicking before anf after flight. Scientists documented increased tail movement pre-flight and post-flight in the Mallard. They may be using this to let flock members know when to leave and when to settle in.
White-throated Dippers, a European song bird always found near water, also increases its tail movement before and after changing locations.
Kiersten: Some birds use their tail flicks to let predators know they,ve been spotted. This is called perception advertisement. A great example of this is the Eastern Phoebe. I’ve always wondered why I see this bird pumping its tail on occasion when it’s perched. I used to think it was for balance because they sit on the edges of branches to scout for insects. Turns out the tail pumping may used to tell a predator, such as a Cooper’s Hawk, “I see you!” Studies have shown the tail pumps increased in the presence of a predator. That doesn’t mean they only pump their tails when predators are present but it definitely increases when a predator is near.
Dusky Moorhens also use this signal. But the really cool thing is that the rate of their tail flicks changed based on the distance of the predator. As the predator increases distance from the Dusky Moorhen, the tail flicking increases. It increases until the predator is at a far enough distance that the moorhen feels it is safe enough to stop flicking and flee.
Cheryl: The last use for tail flicking that we’ll talk about is movement used to flush prey out of a hiding place. Several bird species that eat insects may use their tail flicks to flush prey out into the open where they are easier to catch. The Northern Mockingbird, Painted Redstart, Slate-throated Redstart, American Redstart, Hooded Warbler, and Willie Wagtail all show behavior that are used to flush insects from their hiding spots. According to researchers, Willie Wagtails only move their tails during feeding and rarely during perching. Tail movements also increased in the shade versus bright sun.
There is good experimental evidence from the redstarts as well. The tail feathers of the redstarts are white. In an experiment, researchers discovered that redstarts with artificially darkened tails were significantly less successful in flush foraging.
Kiersten: Research into tail flicking has certainly answered a lot of questions for us, but keep in mind these movements may be used for many different reasons. There are plenty of hypotheses out there about tail flicks that have yet to be proven or disproven. We have a long was to go to understand this bird behavior.
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Summary: How can birds help human mental health? Join Cheryl and Kiersten as they talk about how bird song effects our mental health
Show Notes:
Audubon Magazine Winter 2019
“Why Birds and Their Songs are Good for Our Metal Health,” by Richard Sima
“How Bird Songs Improve Mental Health,” by Arthur Dobrin D.S.W.
“Birding with Benefits: How Nature Improves Our Mental Mindsets,” by Jill U. Adams
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Summary: Join Cheryl and Kiersten for a true story of love and struggle in the time of the bird flu.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“Special Delivery,” by Zoe Grueskin, Audubon Magazine Fall 2023, pages 20-27
Transcript:
Cheryl Intro:
The Arizona’s flock of southwest condors is about 115 birds. These birds roost and roam from the Grand Canyon to Zion National Park. Each bird has a number and most have GPS or a radio tracker so that they may be found if injured or otherwise in need. The spring of 2023 the avian influenza hit the state’s flock of condors killing 21 of these iconic, endangered species. (We have a podcast highlighting the California Condor that was carefully researched by Kiersten, so we are not going to go into the detail descriptions or other details about this bird.) We are going to move forward with our story.
Kiersten:
One of the condors lost this past spring was 316. A 20-year-old female who had succumbed to the avian influenza shortly after laying her egg on a high cliff edge. The egg was being cared for by her mate 680, a 10-year-old male. The odds were against this young male of successfully hatching let alone raising his offspring to young adulthood, especially since the space it inhabited was probably infected with the virus, and biologists didn’t know if the chick inside the egg had the avian flu. So, to save the life of the young male 680, conservation biologists climbed that very high cliff and carefully collected the egg.
Cheryl:
Once the gg was safely transported down off the cliff’s edge it was taken Liberty Wildlife Rehabilitation Center. The clinic staff typically treat a couple of condors a year, usually for lead poisoning. Veterinary staff had little hope for 316’s chick at first. It had been three weeks since 316 had perished, and 680 had been incubating the egg alone. Usually, parents alternate egg sitting duties to maintain a consistent warm temperature for the egg, and to keep each parent healthy. So, the veterinary staff “candled” the egg, illuminating the contents with a bright light. They were looking for blood vessels, or an embryo-any signs of life. What appeared in the rosy glow of the egg’s interior was an embryo that was moving.
Kiersten:
Now, caring for an unhatched chick is round-the-clock work, an all-hands-on deck operation. Condor’s egg is about the size of a soft ball, and was too big for the clinic’s brooder, which will mechanically mimic how adult birds shift their eggs in the nest. Instead, staff gently rotated it four times a day and carefully monitored its development. In May, the chick started hatching but it was pipping at the end of the egg -not the center-the avian version of a breech baby. To survive its eggshell birth, the bird needed assistance. So, using surgical pliers pieces of the shell were carefully, and quickly removed to free the tiny condor. The hatchling was alive, but its fate was uncertain since it was not known if it was infected with the flu. If infected with the flu the chick could not be transferred to the captive breeding facility, a critical step if this chick was to be released into the wild one day. If it had the flu the baby condor would be dead within a week.
Cheryl:
Avian flu has been around for centuries, but in recent decades the virus has evolved to become lethal to wild birds as well as domesticated poultry. A mild version, called low pathogenic avian influenza, is present year-around in some species, particularly in waterfowl, and typically doesn’t cause serious illness. But the virus can travel through waste, infect farmed birds, and mutate into a more aggressive form. The highly pathogenic avian flu, called H5N1, can pass back to wild ducks, geese, and swans, which can carry the virus across oceans and over thousands of miles as they migrate. The last major outbreak in the US 2014-2015, causing the deaths of more than 50 million domestic chickens and turkeys along with a few dozen wild birds, mostly geese before it died out.
Kiersten:
The avian flu that is circulating since 2021 causes severe neurological and respiratory issues and has affected more that 400 bird species in 81 countries. In the Untied States alone, it is responsible for a record 58 million domestic poultry deaths, and FWS has confirmed or suspected avian flu in more than 33,000 wild birds. the virus has killed raptors and swans, ravens and egrets, hundreds of seabirds, and thousands of ducks. This flu has called mammals too such as raccoons, black bears, other meat eaters.
Trying to contain a virus is a formidable challenge-even more so when it is carried by organisms that can fly. It has really impacted conservation and conservationists. There was alarm when Arizona’s condors started getting sick. Condors are in such imperil that they have some advantages that helped them to weather this flu. There are five wild flocks of condors that are intentionally separated by hundreds of miles or more as a safety measure to help ensure that a single disaster or threat doesn’t knock down every group. Each individual bird is monitored, and condors are used to being handled by humans, since the wild birds are trapped annually for health checks. This created an opportunity where there normally would not be one.
Cheryl:
FWS officials briefly discussed bringing every wild condor into captivity as they did 40 years ago, but they opted not to after weighing the daunting logistics, the possible danger from concentrating the entire species during an outbreak, and the fact that the virus was so far restricted to the southwest flock. Instead, biologists watched the birds very closely for signs of illness and tightened biosecurity measures, such s not providing food and water for wild condors. By the time 316’s chick hatched, the tide of death had ebbed.
FWS officials began planning to provide a more dramatic intervention: by vaccinating every single condor against the virus. Now, all condors were vaccinated against West Nile virus in the early 2000’s. So, officials proceeded with caution by first vaccinating a test group of 16 Black Vultures. Black vultures are relative with strong populations, to make sure it is safe and to ensure there was a good immune response. The trial was a success, and this past summer 16 captive condors were vaccinated. Next, will be to vaccinate all the wild condors before the flu picks up again.
Kiersten:
What happened to our little miracle condor chick?? Well, the female chick tested negative for the avian flu. She was transferred to Boise, Idaho, where she was placed with her adoptive parents. Her adoptive parents will raise her to be a condor so she will thrive in the wild. The little condor chick, who is number 1221, will stay with her adoptive family for 7 months then she will join the rest of 2023’s captive-hatched chicks for condor school. A mentor bird will teach the youngsters to strengthen their flight muscles, to eat communally, and to navigate social hierarchy. Then the young condors will be released into the wild in their second summer.
Cheryl: Closing
Where condors are released is determined mainly by each bird’s DNA. Biologists carefully consider which population is the best fit to maintain genetic diversity- which is a crucial concern in a species with so few individuals. For reasons, biologists don’t fully understand males outnumber females making our miracle chick even more important to the story. So, our heroine #1221 may be able to return to her wild roots in the southwest, and play a key role in rebuilding her battered flock.
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Summary: Birds and pesticides do not mix! Join Kiersten and Cheryl as they talk about the history of birds and pesticides, the current status of birds and pesticides, and discuss what we can do in our own backyards.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“Huge decline in songbirds linked to common insecticide.” National Geographic, https://www.nationalgeographic.com
“A neonicotinoid insecticide reduces fueling and delays migration in songbirds,” by Margaret L. Eng, Bridget J. M. Stutchbury, and Christy A. Morrissey. Science, Vol 365, Issue 6458, pp. 1177-1180.
“Take Flight From Lawn Pesticides: Tips for Organic, Bird-Friendly Gardening,” by Hardy Kern, April 12, 2022. https://abcbirds.org
DIY Pesticides: Lawn Love, https://lawnlove.com
Natural Lawn Care Products: Jonathan Green, https://www.jonathangreen.com
For more information on rodenticides and birds please listen to our episode titled: Rodenticides: A Deadly Decision
Transcript:
Kiersten: Intro – Pesticides and birds do not mix. They have a long and devastating history ever since humans have begun using synthetic chemicals. In this episode we’re going to look at some of that history, current issues, and what we can do to help in our own backyard.
Cheryl: As Kiersten likes to do, we’re starting off with the definition of a pesticide. A pesticide is anything that kills off something that humans have decided is a pest. They can be classified into insecticides that kill insects, rodenticides that kill rodents, herbicides that kill unwanted weeds, and fungicides that kill fungus. Every kind of pesticide affects birds. Usually in a detrimental way. Since the 1940s, since the use of synthetic pesticides became more widely used, bird populations have continuously declined. Today around 1 billion pounds of pesticides are sprayed into the environment just in the United States.
Kiersten: Let’s take a look at what brought our attention to the fact that pesticides that we were using in the environment were killing off birds. Some of you may have heard of or read the book Silent Spring. Written by Rachel Carson this book brought attention to what pesticides such as organochlorines were doing to our environment. It focused on a specific pesticide known as DDT. It was used to kill off insects on crops and it was very effective. What we didn’t initially know was the long-lasting devastation that these chemicals could cause in the environment.
All chemicals break down and when DDT breaks down it leaves behind DDE. DDE wreaked havoc on the lives of birds. Organochlorides are extremely persistent. They remain active for a long time and they are fat soluble which means they can accumulate in the fatty cells of organisms that are exposed to them and accumulate over time. I’m sure you see where I’m going with this. Birds that ingested insects sprayed with DDT didn’t just poop out the chemicals, they absorbed them into their system. Then when those birds were eaten by predators, the chemical was passed on to them. This is a process called biomagnification and with each step the contaminants become more concentrated.
All birds were greatly impacted, but raptors were affected most of all because they were consistently eating contaminated food. DDT impacted their entire lifecycle. They died from ingesting the chemical, it was also passed onto the embryos in eggs causing them to never develop, but the most heart-wrenching side effect was the leaching of calcium from eggs shells. Birds were laying eggs with shells so thin that when females sat on the eggs to incubated them, they were crushing their own young.
Because of DDT many species of birds were pushed to the brink of extinction, and we did learn our lesson. Organochlorides have been banned from use in the United States, but other pesticides have taken their place.
Cheryl: The effects of DDT were recognized almost sixty years ago, but today birds are facing threats from another pesticide. Chemicals known as “neonics” are now causing just as many problems as DDT. Neonics are a pesticide used mainly in the farming industry. It is sprayed extensively on crops. It is also used as a coating on seeds so that when the plant grows it will incorporate the neonic throughout the entire plant. It’s great for the plant but it has presented more hurdles for our birds.
The neonics are especially devastating to our migrating songbirds. A research paper published in 2019 has shown that migrating birds that eat seeds covered in neonics lose wait drastically and delay their migration travels. In the study, white-crowned sparrows were monitored with radio telemetry. Researchers found that birds that ate seeds covered in neonics lost 6% of their body weight in six hours and delayed their migration by 3 and ½ days. This is a significant amount of time to delay causing them to miss out on finding mates and territories which can mean they do not breed for the year.
Neonics affect the nervous system of animals that ingest the chemicals. These chemicals are also contributing to the decline of honey bees. The bees lose their ability to navigate back to their hives and eventually starve to death. Neonics may also be harming us. These pesticides are designed to remain in the plant for the entirety of their lives which means the produce from those plants also have neonics in them. Studies are currently on going about how these pesticides affect humans.
Kiersten: Okay! What can we do to help? We can start by looking in our own backyards. If you are a gardener or you have friends or family that garden, you typically take pride in how lovely it looks. As you should! But there are a few small things we can do to help curb the reach of these chemicals.
Here are some tips from the American Bird Conservancy on how to garden responsibly:
Avoid using neonicotinoids, glyphosate, and carbaryl pesticides. Avoid anything that says it is a systemic pesticide.Weed by handUse DIY pesticides. A mixture of diluted white vinegar, salt, and dish soap is a great way to rid your yard of weeds without using synthetic chemicals. According to Lawn Love, you can make a large supply for continued use by combining a gallon of vinegar with a cup of salt and one tablespoon of dish soap. Put this in a spray bottle fro easy use and store in your garage.You can prevent weeds by sprinkling corn gluten around established plants.You can get rid of weeds near the pavement by pouring boiling water on them. Do be careful of splash back.Use organic insecticides that use essential oils to combat insects. Check out a company called Jonathan Green for some great options.And our absolute favorite method. Plant native plants. These plants already know how to combat insects and are best suited for the area in which you live, and attract native birds by offering them what they need to survive.Cheryl: Another way to help is let local, state, and federal agencies know that you are not okay with these chemicals being sprayed on our farmlands. The EPA and FDA have the power to ban the use of these neonics. Other countries have done so, and so can the United States. With all the political craziness going on around us, we often forget that we have a voice. But don’t forget we do have a voice and we can make a difference with votes and petitions.
Kiersten: Thanks everyone for listening and helping our backyard songbirds. Cheryl and I do have an announcement. This is the first episode of our last ten episodes. We will be ending The Feathered Desert. I think I can speak for both of us by saying we’ve have a wonderful time writing and producing this podcast. We’ve learned a lot and we hope you’ve learned a lot, as well. Stick with us for our final episodes though!
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Summary:A three-minute podcast from the hosts of The Feathered Desert about individual bird species found in the desert Southwest.
Show Notes:
Bird song provided by Macaulay Library at the Cornell Lab of Ornithology recorded by Rose Ann Rowlett.
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Summary: Join Kiersten and Cheryl in the final episode of birding by ear. It’s a sought after skill and this episode will help you be the best birder you can be!
Show Notes:
iBird Ultimate: Ultimate Guide to Birds App
Bird song provided by Macaulay Library at the Cornell Lab of Ornithology; broad-tailed hummingbird call recorded by Brett Gleitsman and flight jingle recorded by Paul Marvin; Crested Caracara recorded by Ann Denburgh; Sandhill Crane recorded by Laurens Halsey, white-breasted nuthatch recorded by Wil Hershberger; and Bald Eagle recorded by Scott Olmstead
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Summary: Join Cheryl and Kiersten as they talk about the amazing Pinyon Jay. This is one amazing bird, but they have a land management problem. Listen to find out!
Show Notes:
www.Allaboutbirds.org (Pinyon Jay)
“Spirit of Persistence,” by Anna Johnson and Edwin Juarez, Arizona Wildlife Views PeriodicalSeptember/October 2023 page 17-20
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Summary:A three-minute podcast from the hosts of The Feathered Desert about individual bird species found in the desert Southwest.
Show Notes:
Bird song provided by Macaulay Library at the Cornell Lab of Ornithology recorded by Paul Suchanek.
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Summary: Another way to attract birds to your backyard is to provide nesting possibilities. Join Kiersten and Cheryl as they talk about what kinds of nest boxes you can provide for your backyard birds.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
Birdhouse Features: Features of a Good Birdhouse: https://nestwatch.org/learn/all-about-birdhouses/features-of-a-good-birdhouse
Find the birds near you and the best house for them: Right Bird, Right House: https://nestwatch.org/learn/all-about-birdhouses/right-bird-right-house/
Nest Box designs by species: https://nestwatch.org/learn/all-about-birdhouses
Troubleshooting birdhouses for landlords: https://nestwatch.org/wp-content/uploads/2012/02/nest_box_troubleshooting_20110126_final.pdf
Winter Roost Boxes: https://www.allaboutbirds.org/news/will-birds-use-nest-boxes-to-roost-in-for-warmth-during-the-winter/
Transcript
Kiersten: Intro: We started The Feathered Desert to inform listeners in the southwest about how to feed wild birds successfully and responsibly. We wanted our listeners to know what kind of food to feed to attract the kinds of birds you wanted to see in your backyard. It occurred to me the other day that Cheryl and I have yet to talk about the other way to attract birds to the backyard and that is using nest boxes. So, today’s episode is all about the nest box.
Cheryl: Just like bird feeding, putting up birdhouses in your yard has evolved over the years to incorporate seasonal bird behavior and new scientific discoveries. To truly give the birds outside the best chance at surviving our constantly changing world, there are new guidelines for putting up birdhouses. It’s not a one size fits all device any more. You don’t just put up something that looks great to you and has a hole with a perch under it and see what happens. By observing bird behavior in the wild we’ve determined the best ways to offer birds a safe and secure home for raising young. Following these guidelines is the best way for you to attract even more birds to your yard and enjoy them for generations to come.
Kiersten: First of all, let’s start off with features of a good birdhouse. These features are specific to birdhouses used for nesting, also referred to as nest boxes. There are a few important features for usable nest boxes and they apply to a box you make yourself or one that you purchase.
First make sure the wood is untreated and unpainted. The best woods to use are cedar, pine, cypress, or for larger boxes, non-pressure treated CDX exterior grade plywood.Second, use galvanized screws for construction. These hold up better than nails and are easier to remove when repairs are needed.Third, make sure the roof is sloped and hangs over the main body of the house by 2-4 inches over the opening and 2 inches along the sides. This will help keep out rain even when it gets heavy and the wind is whipping wildly and will also help defend against predators. Adding ¼” cuts under all three edges of the roof will help funnel water away from the house, like rain gutters on our own houses.Fourth, a recessed floor helps keep the nest dry and prolongs the life of the box.Drainage holes on the floor are important, just in case water gets in. You can cut away the corners of the floor if you’re making it yourself or drill 4 holes approximately 3/8” to ½” in diameter on the floor of a premade box.Sixth, to regulate the temperature the walls should be at least ¾” thick. We also want ventilation holes in both side walls, this is especially important in the heat of the southwest. There should be two holes at the top of each wall with 5/8” diameter.Cheryl:
Seventh, predator prevention. Predators are something that birds have to deal with naturally, but remember we are offering them a house that they are not making themselves. When they make their own nest, they disguise it from the predators such as snakes, raccoons, chipmunks, and outdoor domestic cats. The box that we’re offering can stick out like a sore thumb so we need to take a few precautions. First, no perches under the opening! The birds don’t need them and it’s like a welcome mat for predators. Add baffles to the structure where you’ve mounted the nest box. Using collar baffles or stovepipe baffles work great on poles and smaller trees. Noel guards, a wire mesh tube attached to the front of the house, is a good way to protect an opening on a box mounted on a tree that is too large for a baffle.Eight, make sure the opening of the box is the correct size for the birds you want to attract. Remember before when I said there are no one size fits all birdhouses? This is where some of our new information comes in to play. Each species of bird desires a specific size hole for their house. It is very important that the hole in the house is the correct size for the species of bird you want to attract. For example, an American Kestrel needs a hole 3” in diameter, a Northern Flicker needs a hole 2 ½” in diameter, and chickadees need a hole 1 1/8” in diameter. Hole size is also important in deterring non-native birds such as European Starlings and House Sparrows.Nine, rough up the interior wall beneath the opening. Rough walls help the chicks get out when it’s time to fledge. You can use course sandpaper or cut long horizontal grooves into the wood below the opening.Tenth, make sure the back is slightly extended above and below the box to give you room to easily mount it on your pole or tree.Eleventh, last but not least you want one side to be hinged so it can be opened after nesting season for easy cleaning access. Now, we know this is a lot to remember but we’ll share a link in our show notes so you can look up this list later.Kiersten: That’s a perfect segue way into cleaning! This is also new and different from when we used to put up those cutesy birdhouses many moons ago. Do you need to clean your nest box out in between seasons? Yes! It’s very important to clean out old nesting material every year. That why we’re making one of the walls hinged. Removing old nesting material makes sure bacteria and detrimental insects are not passed from one family to the next. Typically, just opening the side panel and removing any plant matter that you find inside is enough, but if you had some especially dirty tenants, using a little warm water and plant-based soap (something like Simple Green or Seventh Generation) to remove poop is a good idea. Clean out your nest box after the last fledgling has left and you don’t see any activity around the box for about ten days. When cleaning remember to protect yourself, as well. Use a dust mask and gloves to prevent any zoonotic disease transfer.
Cheryl: Speaking of seasonal activities, when should I put out my nest box? In the southwest have your nest box mounted and ready for visitors by mid-February. This is typically when our year-round residents begin looking for nesting sites and when our part-time residents are migrating in.
You can leave your nest box up year-round once you’ve found the perfect spot. To prevent unwanted guests such as European Starlings, bees, wasps, or squirrels from taking up residence in the off season you can close up your house. Plug up the opening and cover the ventilation holes like you might do for a cabin you only use in the spring or summer. To prevent honey bees or wasps from colonizing the nest box spray some non-stick cooking spray on the inside of the top of the box. This makes it too slippery for the insects to climb on. When it comes time for nesting season again, open everything up and give it a quick spring cleaning.
Kiersten: Where should I put my nest box?
This all depends on what bird species your box is made for. Every species has a preferred habitat. To help you decide which species you may want to attract go to nestwatch.org (I’ll put the link in our show notes) and they have an interactive page called Right Bird, Right House. This is so cool! You put in what region you live in and what habitat surrounds your house. I put in the Southwest and the desert and it showed me which birds are in my area, where to attach my house, and what kind of house to build or buy. It tells you everything you need to know such as when they nest, how high the box should be, which direction it should be facing, and if they are in decline in your area. Some of the birds they show for the desert southwest are the barn owl, the Bewick’s wren, brown-crested flycatcher, the elf owl, and the Say’s Phoebe. If you live in the White Mountains or summer in a cabin you might put up a house for the black-crested titmouse, the bridled titmouse, the mountain bluebird, or the pygmy nuthatch.
Now a note of caution in the Phoenix Valley, in the severe heat that we get here you need to be extra careful with where you put up a nest box. It should be in an area that is shaded almost all day. If you don’t have any area like that or you can’t put up a device to add shade, you may not want to place a nest box in your yard.
Cheryl: If you put up a nest box but no one seems to be moving in, be patient. It can take up to a year for a nest box to be noticed and used. If you see some interested parties that just aren’t buying, maybe you’ve put it in the wrong place or maybe mounted it too high or too low. There could be other things wrong that we don’t see but the birds do. Nest Watch from The Cornell Lab of Ornithology has a trouble-shooting guide for nest box landlords that you can access online. And we’ll post that link in our show notes.
Kiersten: One last thing about nest boxes that I didn’t even think about until I did the research for this episode. The question came up as to whether birds would use a nest box to roost in the winter? I’d never even thought about that, but as we just discussed we should be closing them up outside of breeding season. So… you can actually have a roosting box for your overwintering birds!
What’s the difference between a nest box and a roosting box? The design of each box is vastly different. A well-designed roost box prevents the birds’ body heat from escaping, so it will have fewer ventilation holes than a nest box. The entrance hole will be near the bottom of the box to prevent the rising warm air from escaping which is opposite of the nesting box. Inside the roosting box there will be several perches to allow multiple birds to roost as opposed to an open area in a nest box where a nest can be made. Staggering the perching will allow for everyone to have their own spot but still be close enough to snuggle for warmth. Roughing up the sides is a great way to encourage clinging birds such as woodpeckers or creepers to use the box. Roosting boxes are usually larger than a single-family nest box to accommodate species that huddle in the winter. Hinging the top panel allows for easy cleaning after the winter season.
This could be a great option for our Phoenix Valley residents who can’t use a nest box because their yards are short on shade. These are not as readily available to purchase already made, but we’ll post a few links that have blueprints for making your own.
Cheryl: Just like feeding birds, placing nest and roost boxes in your yard should only be done if you are willing to take the time to do it right. You must have the time and motivation to use the correct products, place it in the best place, provide predator prevention, and be willing and able to clean it properly. If this is not something you can do in your own yard, reach out to your local birding groups and see if there are any community nest projects you could help with. Schools and daycares often get students to create nest boxes and mount them near their facilities. Maybe you can offer to help them out.
If you do decide to put up a nest box, consider taking the next step and joining Project Nest Watch at Cornell. This is a citizen scientist program that teachs you how to monitor nest boxes for scientific studies. The data you record watching the birds you’re already watching can help further our understanding of bird behavior.
Kiersten: That’s Nest Boxes in a nutshell. If you’re interested in putting one up in your yard please check out our show notes and use the links we’ve provided to get more information to help you successfully offer your backyard birds a great place to raise a family.
A future note: We will be taking a break in September 2023 but we’ll be back with new full-length episodes in October!
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Summary: It is hot, hot, hot! How do birds deal with the increasing heat we’re currently experiencing? Join Cheryl and Kiersten as they talk about how birds keep cool in the summer heat.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
www.audubon.org/news/how-to-help-birds-beat-the-heat/
www.audubon.org/news/the-many-ways-birds-beat-the-heat/
www.sciencedaily.com/releases/2020/11/201112144038.htm
www.birdlife.org/news/2023/08/02/what-ongoing-heatwaves-could-mean-for -bird-populations/
www.audubon.org/news/when-it-gets-too-hot-phoenixs-lovebirds-turn-air-conditioning/
Transcript
Cheryl: Intro:
Extreme temperatures add stress to an already fragile existence yours, mine and our birds.
Heat extreme is threatening bird populations, with the hottest July on record here in Phoenix behind us let’s look at how birds handle the heat, wildfires, and how we may help.
Kiersten: The adaptions birds have to keep cool.
Birds in general are well insulated and just like us they heat up when they exercise. Imagine wearing a down jacket all the time, even when you exercise. Yep! That’s a bird. Wild birds are always, in a way, exercising, so birds have to be careful not to overheat.
Anatomical adaptions: Shorebirds wade in cool water, this helps their bodies to release heat. Waterfowl also use water to regulate their body temperature. Dark Plumage can actually be cooler than white or light-colored feathers. It may seem counterintuitive that so many birds in hot climates are black or darker colored, but studies have found that there are advantages to having these drabber colors.1)Darker feathers do get hotter than white feathers, but because these feathers provide such good insulation very little heat reaches the bird’s skin.2) Dark feathers absorb light and heat at the surface, where it can easily radiate back to the air. Dark feathers are more resistant to wear and help block UV radiation, dark feathers also allow birds to be more inconspicuous when resting in the shade, but visible to their flock mates.Birds don’t sweat, they generally cool off by panting. Gular flutterDesert birds have evolved to avoid exertion during the hottest part of the day.Many desert bird species have long-term pair bonds and maintain year-round territories, reducing the need for energetic displays. Fighting is relatively rare. And there are many mechanisms to shelter eggs and chicks from the heat and to provide water.Cheryl: Heat and baby birds
Extreme heat in the southwest can be devastating to young birds. Baby birds will jump from nests to find relief from the heat. Sometimes they find something soft to break their fall, other times not. A nestling’s tiny body is still in development, and the tiny bird struggles to regulate its temperature-which is one reason why parents sit on their young, to help buffer the cold and the heat. Not only are baby birds less efficient at relieving heat stress, but they also have limited mobility, and this can lead to nestlings in open nests like hawks, some owls, even our curve-billed thrasher babies exposed to direct sunlight. This sometimes, leads to these birds leaving the nest too early because they are too hot.
Birds don’t sweat, they pant instead. Unfortunately, panting is an active process that requires a lot of muscle movement. So, it is a double-edged sword; to offload heat by panting, birds basically have no choice but to produce heat. Scientists are concerned that chronic heat stress is going to lead to nest failures. This could risk the future of 389 North American bird species.
Kiersten: Wildfires
Wildfires are becoming hotter, more numerous, and fiercer with the warming of the climate, we can see that with the most recent wildfire on Maui. A wildfire refers to an unintentional, uncontrolled fire.
How do wildfires impact wildlife and their habitats? After a wildfire in Flagstaff, two porcupines were seen walking slow and funny, more so than they usually do. They were picked up by wildlife rescuers. It was discovered that these animals had burns on their feet from walking on the hot coals. So, what is happening in the aftermath of fires -just animals having a hard time and being pushed into areas they are not traditionally in.
Birds, if they can fly, will fly away from the fire, but young birds like nestlings cannot fly, and are left to perish. Wildlife rehab centers are filled with birds that have had their feathers singed, or melted from the heat of wildfires when flying overhead to get out of the way.
Scientists are studying the effects of climate change wildfires to better understand how birds and other wildlife manage once their homes have been burned.
Cheryl: Pros and Cons of the effects of fire on wilderness areas.
Cons:
Burn and damage vegetation communities, such as rainforests and deserts that take up to hundreds of years to recover.Kill or injure individual plants and wildlife, including birds.Causes erosion and subsequent sedimentation of creek and wetlands.Open up areas to the impacts of weed, invasive plants, and feral animal invasion as well as human access and vandalism.Pros:
Heats the soil, cracking seed coats and triggering germination.Triggers woody seed pods held in the canopy to open, releasing seed onto a fresh and fertile ash bed.Clears thick understory reducing competition for seedlings.Encourages new growth that provides food for many animals.Creates hollows in logs and trees that can be used by animals for nesting and shelter.Native animals can escape fire by fleeing to “unburnt islands” within a burn area or to surrounding unburnt vegetation. Insects, reptiles, and small mammals may be unable to hide underground, and animals that live in trees can move to treetops and escape low to moderate intensity fires. Birds are the least impacted by fire as they can fly away, but their babies and the eggs can be impacted depending upon the season of the fire or heatwave. There have been “events” where a large mass of birds has suffered and been lost due to fire. Several years ago, migratory birds were falling out of the sky over New Mexico due to smoke damage, and starvation.
Kiersten: Lovebirds and the Phoenix heat.
Rosy-faced lovebirds are pet trade escapee’s native to southwestern Africa that were first documented in the 1980’s in the Phoenix Valley. They have flourished in the city where they nest in cavities of ornamental plants and cacti. Their population is now estimated at more than 2000 individuals. But the parrots haven’t ventured far outside the city’s urban areas. This suggests that these birds relay on humans to survive in a desert hotter and drier than their home turf.
Phoenix lovebirds have figured out a creative way to beat the heat, by perching on buildings near air-conditioning vents, or swamp cooler vents taking advantage of the cool air that is leaking out through the cracks. These parrots find their water sources at golf courses, bird baths, fountains and parks with ponds or lakes. Phoenix’s lovebirds’ inventive adaptions to extreme heat are an example of how birds, and wildlife in general, is going to have to change their behavior to cool in the heat.
Cheryl: How can we help birds to beat the heat?
Offer water. The higher the air temperature is the more water they have to evaporate, and the more frequently they have to drink. Birds cool down by bathing. The water directly lowers their temperatures and absorbs heat energy as the liquid evaporates from their skin.Provide shade. In addition to panting and bathing birds beat the heat simply by avoiding it. Many species will stop foraging during the hottest part of the day, choosing instead to shelter in cooler, shady spots.Supply food. Native plants provide plenty of seeds, berries, and fruit, as well as hosting insects-food resources that can become scarce during periods of extreme heat.Heat waves typically happen during breeding season, when 96 percent of native North American bird species depend on butterfly and moth caterpillars to feed their young. You can help those birds feed their babies when temperatures spike by cultivating native plants.For some species, bird feeders can also help supplement food resources.Take action. Advocating for native plants in parks, and municipal landscapes. Work with in your community for change to lower temps in your city.Closing:
Humans are impacted by extreme heat just as birds are. If we make it more comfortable…more survivable for birds on Earth, then humans benefit too.
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Summary: There are three categories of birds that can be found in the wild. Join Cheryl and Kiersten as they discuss the research of wildlife scientist John Marzluff and how it pertains to the birds in our backyards.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
Welcome to Subirdia: Sharing Our Neighborhoods with Wrens, Robins, Woodpeckers, and Other Wildlife, by John Marzluff.
Transcript
Cheryl Intro:
Ever wonder who moves into the neighborhood? Birds, as adaptable as they are do not always want to live with humans, nor do they always benefit by sharing space with humans. In the book Welcome to Subirdia, the author, John Marzluff, a professor of Wildlife Science writes about this. His team of graduate students studied urban, Subarian, and forested areas to identify and count the bird species in areas around Seattle, Washington. Let’s take a look at our region of the southwest; which birds thrive in our presence, which birds adapt to living with us, and which birds choose to stay clear of human activity.
Kiersten: Avoiders
Avoiders are those native bird species that are extinguished or decline over time as urbanization intensifies. Birds like Burrowing Owls, Green heron, Orange- crowned warblers, Scarlet Tanager, or even the Scott’s Oriole, and the Hairy Woodpecker. These birds all have varying degrees of sensitivity to human development. They move farther and farther away from it. This is true of the hairy woodpecker. It builds its nest in dead trees. What HOA allows dead trees?
Burrowing owls are susceptible to predation by people’s pets, and feral cats. So, these ground dwelling owls of our local desert are pushed farther and farther out. Some birds like the Green Heron just likes its privacy, so it has a low tolerance for our activities. Scott’s Oriole, and the Scarlet Tanager enjoy forested areas, and hunt insects. Orange-crowned Warblers enjoy riparian areas. So, we can appreciate why these birds find their choice habitats not in our backyards.
Cheryl: Exploiters
Exploiters are species that thrive in our presence, often coevolving with humans and rarely occurring where people do not exist. Birds such as the American Crow, Northern Mockingbird, Barn Swallows, Barn Owls, Mallards, Canada goose, house finches, and house wrens, house sparrows, European Starling, our beloved lovebirds, and pigeons (Rock Doves). I was surprised by some of the birds on the list. These birds move into the niches vacated by those birds who find themselves more of an avoider. A few of these birds’ humans are responsible for introducing into the urban areas they are thriving in. Each species soars in abundance as soon as clearing begins and increases over time. Most of these species are not present in forested areas in large numbers. The ability of these species to capitalize on the lawns, lakes, and nesting niches created in built environments likely explains their success.
Kiersten: Adapters
“Adapters are mostly native species that thrive on natural, young, open shrubby, and dissected habitats.” (Quote from Welcome to Subirdia,) An interesting description of our neighborhoods and backyards. Adapters find and adjust to situations in our cities, urban, or suburban areas even if the natural habitat is man made.
This is the largest group of birds, which is encouraging, but these birds decline when the areas grow too close to forested habitats, or yards become overgrown, or trees too mature. Birds like Anna’s hummingbird, White-crowned sparrow, American goldfinches, Lesser goldfinch, Song sparrows, rock wrens, Curve-billed thrasher, Killdeer, and the Yellow-rumped warbler are all birds that adapt to human changes in their habitat as long as the changes are within reason.
Kiersten: Why is this information important you ask.
It is important to know how birds are adapting or not adapting to human activity so that we may better understand how we may improve our living spaces so that we make room for birds to live, too. Birds can move from one category to another for example: a bird could be an adapter until the stresses of human activity pushes it to be an avoider, or it could move from adapter to being an exploiter, like the Northern Mockingbird it all depends on how a particular species handles what humans do to their habitats.
Cheryl: Closing
It is not surprising that birds can handle many of the challenges of living people, given that they have wings to propel them away from humans, if need be, and they are linked to dinosaurs, adding their engaging personalities, flexible behaviors, and short generation times, all these things help birds to succeed in even the toughest parts of our human-dominated world.
We are capable of applying this knowledge to our backyard living spaces, parks and recreation areas, and make the adjustments necessary to support the bird life that is present now, and to build toward greater diversity in the future.
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Summary: In this episode Kiersten and Cheryl talk about how birds have influenced us to create some amazingly cool technology.
For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“The Amazing Secrets of Woodpecker Tongues,” by Rebecca Heisman, June 10, 2021. American Bird Conservancy. https://abcbirds.org
“Geese Inspire New Airbus Formation Flying Technology,” by Kathleen Bangs, December 2, 2021. https://airlinegeeks.com
“How the wings of owls and hummingbirds inspire drones, wind turbines and technology,” by Ilias Berberi, Carleton University, The Conversation, May 11, 2020. https://theconversation.com
“Next-gen e-readers: Improved ‘peacock’ technology could lock in color for high-res displays,” February 5, 2013, University of Michigan. https://www.sciencedaily.com
30 Animals That Made Us Smarter podcast, episode 1-Kingfisher and bullet train and episode 4-Woodpecker and black box. BBC World Service, bbc.co.uk
Transcript
Kiersten: Intro – Sometimes we take birds for granted. They are just a part of our daily lives that we don’t focus on, but occasionally we notice their extraordinary characteristics. When the right person, such as an engineer, notices these amazing attributes they are often inspired by the birds and create or improve man made devices. In this episode Cheryl and I are talking about biomimicry and how birds influence us.
Cheryl: Let’s start off with a definition of biomimicry. According to the Oxford Languages dictionary the definition of biomimicry is the design and production of materials, structures, and systems that are modeled on biological entities and processes. The word itself literally means imitation of the living. So basically, we learn from nature how to create things that work well. For example: those burrs that get stuck on your socks in summer influenced the creator of Velcro, shark skin led to more hydro-dynamic swimwear that Olympic athletes now use, and dragonflies influenced the design of helicopters.
Kiersten: When we listen to what nature can teach us, we can invent some pretty spectacular things. Let’s look at a few creations that birds influenced.
Japan’s Bullet Train: The bullet train can reach speeds of up to 300 mph. It’s a modern marvel of human engineering and has made travel in certain regions of Japan very efficient. There was a problem with the first design though, a rather seriously annoying problem. The flat faced design of most passenger trains is fine for trains that travel at more typical speeds of 60 mph or so, but that design at 300mph creates a sonic boom noise when exiting a train tunnel. This was a big problem because it was causing serious noise pollution. As the train passed through the tunnel, the air built up in front of the train and then exploded upon exiting the tunnel. People that lived along the route of the train were being awoken at night and were disturbed during the day. It was also scaring local wildlife. Something needed to be done and fast.
One of the engineers on the project was a birdwatcher. One day when he was birding at a lake, he saw a kingfisher diving into the water to catch a fish. As the bird entered the water, the surface of the water was only slightly disturbed. It was like the kingfisher’s bill cut through the water. The engineer thought about this when the noise problem presented itself. Using the kingfisher’s long, sharp beak as a model, he restructured the nose of the bullet train and reduced the noise to almost nothing. It also increased the energy efficiency by 10-15%. So, thank you kingfisher!
Cheryl: Silent Flight
The silent flight of owls is one of their most useful adaptations. Sneaking up on their prey in the dark of night is what makes them extremely successful predators. Recently researchers have looked to the structure of owl feathers to help solve a problem with wind turbines.
The development of wind turbines is one of mankind’s brilliant attempts toward eco-friendly energy production. We know that this source is not perfect but engineers are constantly working on improvement. One of the complaints is how noisy wind turbine farms can be, so scientists have looked to the owl for a solution.
They looked at the structure of the owl’s feathers to determine how they are so quiet in flight. Owl feathers have sharp edges, also known as serrations, along the front edge of the feather. This sharp edge breaks up the air turbulence created during flight. Breaking up wind turbulence reduces the noise caused by the turbulence. The back ends of owl feathers are fringed. The fringe structures disperse even more air turbulence once again reducing the sound created in flight. Both of these structures help owls fly silently.
To combat noisy wind turbines, researchers are attempting to apply the structure of the owl’s feathers to the blades of the wind turbine.
Kiersten: Hummingbirds and drones
We all know and love the hummingbird here at The Feathered Desert. Everything about the hummingbird is a miracle of nature. One of the most fascinating things to engineers and scientists is how hummingbirds fly. They don’t just flap their wings up and down like other birds do, they actually flick their wrists which allows them to produce a figure eight pattern. This allows hummingbirds to fly forward, backwards, hover, and even fly sideways.
Drones have become a fixture of modern society, whether we all like it or not. Drones can be used for all sorts of things such as surveillance of terrain that humans cannot get to on foot, getting accurate counts of wildlife without disturbing them, and even delivering sperm from endangered birds to waiting scientists. (For more on this check out our episode Conservation Technology). Drone engineers are always looking for ways to improve their creations. In the last decade, they have taken notice of the hummingbird’s gravity defying abilities.
Creating drones that can maneuver through the air like a hummingbird could be the next step in drone technology.
Cheryl: Geese V-formation
For generations we’ve known that the v-formation of geese helps them survive the long migration flights they perform twice a year. The leader at the front of the v-formation takes on most of the energy expense while those flanking the leader are able to draft off of their hard work. They share the burden by rotating who is in the leading position. It’s a great way to conserve energy on long trips.
A group of students at Stanford University used this lesson from nature to propose a way to conserve energy in the airline industry. Airbus is a company that designs and builds airplanes and other aerospace technology. Always looking for ways to improve airplanes and air travel, they host competitions for innovative ideas. The group of students at Stanford entered an idea based on the v-formation of geese. They said if airplanes flying cross country could draft off of each other they could save fuel and reduce carbon emissions.
The students didn’t win the competition but Airbus loved the idea so much that they tried it out. They launched two Airbus jets from Toulouse, France. Once airborne, they maneuvered into a tandem formation and flew across the Atlantic Ocean landing in Montreal, Canada. The flight was a success. The planes flew and landed safely, saved more than 5% of fuel, and reduced their carbon emissions by over 6 tons.
Kiersten: Woodpecker and collisions:
Woodpeckers have incredible collision absorption abilities. We’ve all heard woodpeckers banging away on wooden or metal surfaces, but have you ever stopped to think of how much force the woodpecker creates when they do that and how do they survive constantly beating their face on hard surfaces.
Woodpeckers actually beat their beaks against a surface 22 times a second without causing any damage to their brain. They are creating immense G-forces when they do this. G-force stands for gravitational force. This is the force that impacts beings as they move through space. An airplane take-off creates 2 Gs, fast roller coasters create 5 Gs, humans pass out at 6 Gs. Woodpeckers peck at trees at a force of 1,200 Gs. So how do they survive such a force without their head crushing?
They have four shock absorbing adaptations. 1- their chisel-shaped beak is tough but elastic. It is slightly malleable and able to absorb vibration. 2- their hyoid bone, which anchors the tongue, wraps around the entire skull like rubber tubing, 3- the bone of the skull is actually spongey. The bone is thick and packed with microscopic plates creating a woven mesh that stops low frequency vibrations from passing through. 4- the skull hugs the brain snuggly. They don’t have fluid in skull like us. The fluid actually makes us highly susceptible to concussive forces. They woodpecker’s brain won’t knock around inside its skull when it bangs it’s beak against a hard surface.
Two researchers from UC Berkely used the woodpecker’s collision adaptations to improve protection for electronic devices such as black boxes on airplanes. They built a protective system that mimics the four-layer protection of the woodpecker. 1- They designed a cylindrical structure for the outer most layer that was like the beak. 2-They added a layer of rubber inside like the hyoid. 3- They added glass beads inside that mimic the spongey bone and 4- a second layer of metal directly around the electronics. This design protected the electronics up to 60,000 Gs. Thanks woodpecker!
The woodpecker also inspired a student to design a better bike helmet. This student was an avid biker and he suffered a concussion after involvement in a bike accident. He was wearing a bike helmet but it cracked and he suffered a concussion. He was inspired by the hyoid bone of the woodpecker that wraps around the skull and the spongey bone of the skull. He invented a dual density cardboard with a honey comb patterned (also inspired by nature) liner for bike helmets. It was light and performed very well at absorbing impact. And its recyclable!
Cheryl: Peacock feathers and digital screens
Our last example of biomimicry involves one of the most beautiful birds, the peacock. Their feathers are an iconic image used for so many things in our human cultures. The colors are eye popping and we often try to mimic the beauty of the male peacock’s tail feathers in our art. Their beauty relies on iridescence, a sheen that shifts color depending on your viewing angle. Peacock feathers never lose their bright vibrant colors, and that’s because the color is created by structure not pigment. Since the first high-resolution screen was invented, researchers have been trying to improve the color images that they display. They have now looked to the peacock for inspiration.
Researchers at the University of Michigan have found a way to lock in structural color by using texture instead of chemicals. The peacock’s tail reflects light off of small grooves on the surface of the feather. The grooves only reflect certain wavelengths of light depending on the angle of the light to the groove. That’s why peacock feathers are shimmery. The University of Michigan researchers have discovered how to trap the reflected colors of light in metallic grooves making them permanent. This could lead to advanced color ebooks, electronic paper, and color reflective screens that don’t need their own light to be readable. Reflective displays would also use much less energy than our current backlit digital screens.
Kiersten: It is amazing what we can learn from nature, if we just let ourselves listen.
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Summary: Have you ever noticed how many different eye colors birds have? Join Kiersten and Cheryl as they delve into this understudied topic.
For our hearing impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“Bird Eye Color” A Rainbow of Variation, a Spectrum of Explanations,” by Eamon C. Corbett, Robb T. Brumfield, Brant C. Faircloth. https://ecoevorxiv.org/repository/object/3682/download/7316
“Bird Eyes Come In an Amazing Array of Colors – but Why is a Mystery,” by Meghan Bartels; Audubon February 2023. www.audubon.org
Our email address, please reach out with comments, questions, or suggestions: [email protected]
Kiersten: Intro: Eye color in birds is often something we might overlook. But it’s incredibly fascinating. Bird’s eyes come in a variety of colors and can even vary throughout one individual’s life. Today Cheryl and I are going to talk about eye color in birds.
Cheryl: We all know how colorful bird’s feathers appear. They can be blue, red, yellow, even green. This is one of the reasons birds have been studied by scientists for so long and one of the main reasons we want to attract birds to our backyards. We want so see those bright, fabulous colors. Scientists want to know what’s up with all the colorful feathers, and while this is fascinating and important research, it has overshadowed the other amazing colorful characteristic of birds: their eyes.
Here in the southwest, the Curve-billed Thrasher, is an example of bird with a brightly colored eye. Adults have bright orange eyes. It’s an iconic characteristic and a great way to distinguish them from other types of thrashers.
Birds’ eyes come in many different colors from dark-brown to light-brown to reds, oranges, yellows, greens, blues, and even white. Within these colors, a range of hues exist such as the turquoise of the Double-crested cormorant, the emerald green of the Black-and-red Broadbill, the crimson red of the Bronzed cowbird, the sunset orange of the Painted buttonquail, and the school bus yellow of the Short-eared owl.
Birds even have multi-colored irises. Our Curved-billed Thrasher’s orange eye is actually a combination of an outer ring of orange with an inner ring of yellow to red near the pupil. The underappreciated Rock Pigeon actually has a beautiful eye with a ring of red on the edge and a ring of yellow around the pupil. The Greater Roadrunner, another of our southwest residents, has an eye with rings of brown and yellow around the pupil. Most of the birds with multi-colored iris have symmetrical coloration, but a few have asymmetrical coloration.
The Bank Cormorant’s eye is an earthy orange on top while the bottom looks like a turquoise stone. Looking at this bird’s eye is like looking at an Arizona sunset. Some female oystercatchers have dark eye flecks on only one side of the pupil giving their eye a keyhole appearance.
Kiersten: It is amazing the colors that are found in the avian world, but the light bright colors are less prevalent than the darker colors. A study released early this year, in 2023, has compiled information previously researched about eye color and they noticed some trends.
It appears that more birds have darker eye color, such as brown and black, than light eye color. Birds, as a whole, have darker eyes on average than other vertebrate groups including mammals, reptiles, and amphibians. Looking at passerines, such our songbirds, 64% had black to dark brown eyes, 19% had light brown to red eyes, and 17% had the lightest eye colors including yellow, orange, white, pink, blue, and light gray.
Non-passerine birds, such as hawks, owls, ducks and other water birds, have lighter eyes than passerines. 40% were dark, 22% were the intermediate light browns and red, while 38% were light. The dark versus light hues found in birds do tend to follow phylogenetic lines. Birds in related families tend to have the same level of eye color. They may not always have the same eye color exactly but they are often categorized the same as dark, medium, or light. What we’ve talked about so far is differences of eye color between species but there are differences in eye color within species.
Cheryl: There are typically three reasons eye color will vary within a species. Number 1: Some birds are born with a darker eye color that will lighten as they age. For example, our Curve-billed Thrasher is born with brown eyes that change to orange only when they are adults. Spotted towhees have dark brown eyes as juveniles that turn red when they are adults. Osprey chicks are born with orange eyes that lighten to yellow when they are adults.
Number 2: Twenty-four species of birds have been shown to have differences in eye color between sexes. Essentially males and females of the same species will have different colored eyes. Common grackles are a good example of this. The males have bright yellow eyes, while the females have brown eyes. Brewer’s blackbird females have dark brown eyes while the males have a bright yellow. In a reversal, Saddle-billed Stork males have dark brown eyes while the females have bright yellow eyes.
Number 3: Eye color can vary seasonally. A small handful of birds that we currently know about will change eye color during breeding season. The Brown Pelican male’s eyes will change from a brown color to a light blue at the beginning of breeding season and remain blue until incubation begins. The male Great Blue Heron’s eyes will turn red during breeding season and be yellow the rest of the year. Female chickens eye color may change when they are laying eggs.
There are a few birds that are able to change their eye color based on their mood. They can expand or contract the blood vessels in their eyes to change the color of the iris. We actually have a bird in our own backyard that can do this, the Inca Dove.
For those of you who are cross-country birders, you may be familiar with one last reason that the same species of birds can have varied eye color, population differences. Species that have a large habitat range can develop differences in eye colored based on the eye color that is most popular in a specific region. For example, a House Finch from Arizona might have a slightly different eye color from a House Finch born in New Jersey. They will most likely be in the same range of color but they can vary.
Kiersten: Now that we know what kind of colors exist in birds’ eyes, let’s look at how these colors are created. In humans’ eyes different levels of melanin create our eye color. Melanin is also involved in creating color in bird feathers, for more on this please check out our previous podcast on feathers. If you are thinking melanin is involved in creating bird eye color, you’re partially right!
There are a variety of pigments, blood vessel dilation, colorless oil droplets, collagen fibers, and other structural features that create the colors that we see in bird eyes. According to the 2023 research paper, color created by chemical pigments are created by living cells called chromatophores which is unique to avian eyes.
To further amaze us, we cannot assume that one bird with a red eye created by the carotenoid pigment means that all birds with red eyes have carotenoids making their eyes red. For example, Canvasbacks, Red-eyed Vireos, and Bronzed Cowbirds all have red eyes but they are all produced by different means. Canvasbacks red eyes are created by carotenoids, Red-eyed Vireos are created by another pigment called pteridines, and the red eyes of Bronzed Cowbirds are caused by the dilation of blood vessels in the eye.
The known mechanical contributors of bird eye color are carotenoids, melanins, purines, pteridines which are all pigments, and blood vessels, collagen fibers, oil droplets, and cholesterols. Birds can have reflective structures such as a crystalline pteridine or purine, colorless oil droplets, or collagen bundle in the eye that often creates the lighter colors. To create, color birds can have one or a combination of any of these. Species with only pigments present in the eye typically have a duller eye color such as the Northern Flicker and the Cactus Wren. Now, I’m not saying their eyes aren’t a nice color or even a pretty color, I mean more like the difference between a shiny new penny versus an older well-worn penny. Birds with only reflective structures in the eye have a white iris, like the Acorn Woodpecker.
Generally speaking, birds with darker eyes have more melanins while birds with lighter eyes have more purines and pteridines. Birds with bright, almost sparkling eyes have reflective structures such as crystalline purines or pteridines, collagen bundles or oil in the eye. The next question is why do birds have so many different eye colors?
Cheryl: The answer is….. we don’t really know. Very little research has actually been done on eye color in birds. What we can do is generalize about eye color based on other attributes of birds. We know that birds that molt into adult colors do not breed until they have their adult color pattern, that could be a reason for juvenile change of eye color as well. The change of eye color may indicate readiness to breed. The same can be said for changing colors before breeding season. A male with a good head of feathers can indicate a healthy male and attract female attention. This might be the same reason for the change of eye color before breeding season begins.
Other reasons could be survival. The birds with a particular eye color survive best and they are the ones to pass down their genetics. Maybe the eye color allows them to camouflage better than other individuals. Maybe it’s based on how they obtain food. Foragers versus hunters? Is there a pattern to who has which eye color? What about their habitat? We do know that birds that live in sunnier places have more melanin in their feathers because it makes them last longer. Maybe this is also true for their eye color? Maybe the melanin protects their eyes. Does the eye color have anything to do with communication between individuals of the same species? We know that wing postures, feather color, and sound are all important in communication, maybe eye color is as well. Or does none of this have anything to do with eye color at all?
Sadly, we don’t have the answers because no long-term research has been done on bird eye color. It is definitely a topic that needs much more attention in the future.
Kiersten: One of the things we can do as citizen scientists to help this research along is take pictures! Especially those of you with the patience for wild bird photography. Taking pictures of birds eyes with your telephoto lenses and uploading them to eBird will help these scientists move forward in their research.
Closing: What we’ve talked about in this podcast probably seems like a lot of information, but this research was only done on a small portion of bird families. We need much more research done concerning bird eye color. And, we don’t know yet, but this could be the next big epiphany we have in animal behavior. What we know today is terribly fascinating, but I think many more amazing discoveries await us in the future.
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Summary: “You eat like a bird!” We’re sure you’ve heard this before and may have even said it, but if you knew what we know, you’d probably never say it again! Join Cheryl and Kiersten as they talk about some of the strange things birds eat!
For our hearing impaired listeners, a transcript of this podcast follows the show notes on Podbean.
Show Notes:
“Cassowaries: Crucial to Rainforest Ecology,” The University of Waikato, https:blog.waikato.ac.nz/bioblog/2009/12/cassowaries-crucial-to-rainfor/
www.allaboutbirds.org
American Bird Conservancy, https://abcbirds.org
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Cheryl: Intro
Have you ever heard the expression “You eat like a bird.” What did that really mean? I personally never got it, but I heard many times. If the person who coined that phrase really knew what birds ate, I don’t think that it would have been said at the dinner table. Today let’s look at the weird things’ birds eat and a little about how they do it.
So, there’s the Phainopepla that consumes mistletoe berries, and a lot of them; this bird can do this because they have a specialized digestive tract to accommodate this particular berry. Then there is the American Robin, that changes it digestive system to be able to adjust to the transition from protein-rich invertebrates in spring and summer to fruits and berries in winter.
Kiersten: Worm-Eating Warbler
This warbler is small, rather drab in color with a black and buffy head stripes on its flat head. This flat head helps it to get into all the nooks and crannies of the forest floor where it consumes caterpillars and slugs, insect larvae but not earth worms like the name suggest. This warbler has a beautiful song that helps it live up to the warbler part of its name even if its drab in color.
Cheryl: Shore birds and Sapsuckers
Birds like the Black-necked Stilt, and the American Avocet are shore birds that eat mollusks such as clams, oysters, snails, and slugs found in the muddy water along the edges of creeks, rivers, lakes, ponds and irrigated fields and agricultural fields.
Then there are birds that feed on the mucus of plants and trees, namely sap. These birds are woodpeckers, waxwings, kinglets, and warblers which all have a component of sap/mucus in their diet.
Kiersten: Red-tail Hawk and Great Horned Owl
Rattlesnakes and Red-tail hawks, two very capable predators, but if an adult red-tail hawk locates a rattlesnake out in the open, it’s a dead snake crawling. Rattlesnakes are a favorite meal for this hawk. Red-tail hawk doesn’t sneak up on a rattlesnake, if it did that it would actually give the rattler the advantage. Instead, the hawk flies down and perches right in front of the snake. There by taking the lead in what is often called the “dance of death.”
The hawk will fan out its feathers, exhibiting its 5 ft wing span.In response, the rattlesnake will rattle it’s tail in a warning, and will puff up to look bigger and more formidable. This might work.If not, the hawk will then hop or walk around, essentially trying to divert the snake’s attention.This will likely trigger the rattlesnake to snap open its mouth and display it 5-7” long fangs, and with the coiling motion, it will lunge forward.Then the hawk hops onto the snake and end the snake’s life. Red-tail hawks don’t eat the head of the snake therefore avoiding ingesting any venom.Great Horned Owls have excellent night vision and a poor sense of smell, which helps it deal with one of its favorite meals- skunk. So, when you are out in the wilds of Great Horned Owl habitat and you smell skunk, but don’t see one you could be in the area of a Great Horned Owl nest.
Cheryl: Scott’s Oriole and Western Tanager and the Cassowary
Scott’s Oriole is a fruit eater, not only do these birds eat dagger cactus fruit, but also cultivated fruits such as apricots, peaches and figs. The Western Tanager lives off of insects such as bees and wasps in the spring and summer. Then in the winter months it will enjoy berries…all kinds like hawthorn, wild cherries, elderberries, blackberries, mulberries and service berries.
All the above-mentioned birds may be found in our state of Arizona, but there is one fruit eater that lives in Australia and Papua New Guinea, the Cassowary. This bird is the third largest bird in the world with an adult standing up to six feet tall. These birds live in the rainforests and are considered keystone species because of their role as a major seed dispenser of up to 238 rainforest plant species. Over a 100 of these plants’ species depend entirely on Cassowaries to dispense their seeds.
In some cases, cassowaries are the only bird to be able to digest the fruit of certain plants such as the Cassowary Plum. This fruit contains a sap that is poisonous to humans and most other animals.
The Cassowary’s unique digestive system which is short and fast, to digest the fruit. The Cassowary plum is an important food source for the Cassowary, and in turn the bird than distributes and helps germinate the seeds of the plant.
Cheryl: Closing
Now doesn’t this make you think twice about that old expression” You eat like bird”. Really do you?
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