The Feathered Desert Podcast

What’s That Bird?: Bullock’s Oriole

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.

Birding by Ear in the Southwest: Part 5

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

The Pinyon Jay: A Bird with a land management challenge

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

What’s That Bird?: Red-tailed Hawk

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.

Better Birdhouses for our Backyard Friends

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.

1. 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.
2. Second, use galvanized screws for construction. These hold up better than nails and are easier to remove when repairs are needed.
3. 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.
4. Fourth, a recessed floor helps keep the nest dry and prolongs the life of the box.
5. 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.
6. 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:

7. 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.
8. 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.
9. 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.
10. 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.
11. 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!

It’s Hot! Extreme Heat and Our Birds

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 flutter
• Desert 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.

Avoiders, Adapters, and Exploiters

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.

 

 

 

 

Biomimicry: Humans Learning from Birds

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.

Bird Eye Color

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:  thefeathereddesert@gmail.com

 

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.

           

 

Unusual Eats

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

Our email address, please reach out with comments, questions, or suggestions:  thefeathereddesert@gmail.com

 

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?