The Science of Birds - Bird Habitat: Deserts

Episode Date: February 29, 2024

This episode—which is Number 92—is all about the value of desert ecosystems as habitats for birds.Deserts are important for the birds that are adapted to live in them—birds that can handle the harsh conditions. Deserts are home to relatively few bird species. Only the polar regions and maybe some parts of the open ocean have less bird diversity.Even if a bird species can handle the extremes of heat and cold in a desert, the desiccating winds, and the lack of water, that bird may not find much food. Because where there are few plants, there are few invertebrates. So a bird in the desert can have a hard time finding any leaves, seeds, fruit, or bugs to eat.And yet, an assortment of bird species from many disparate families have managed to carve out an existence in the world’s most arid lands. There may be nowhere near as many of them as in, say, a tropical rainforest or a temperate woodland…BUT, the birds we do find in the desert are, I think, a particularly fascinating and admirable bunch. They’re tough little buggers. They’re resilient. Desert birds have interesting adaptations and behaviors that allow them to survive in places that would kill most other birds in a day.CORRECTIONS: I realized after I recorded this episode that I mispronounced the names of the Namib and Thar deserts. Namib should be pronounced "NAH-mib." Thar is pronounced "Tar." Links of Interest Grayish Miner in the Atacama Desert [VIDEO]   ~~ Leave me a review using Podchaser ~~Link to this episode on the Science of Birds website Support the show

The driest place in the world lies along the west coast of South America in northern Chile. This is the Atacama Desert, a 1,000-mile-long stretch of desolate, otherworldly landscapes. The average rainfall here is about 0.6 inches, or just 15 millimeters per year. But some parts of the Atacama Desert have gone for centuries with no record of rain. What is this place like? Imagine the whisper of wind blowing over barren rocky slopes and across salt flats. In the distance are towering rock formations with layers in hues of rust red, pink, and yellow. On the horizon are cone-shaped volcanic peaks, dusted with snow.

The sun blazes overhead in a sterile dome of deep blue sky. Living things are scarce in the Atacama Desert. It's too dry for most plants and animals, and the temperatures are too extreme. And yet, there's at least one bird that calls this place home. It's the grayish miner, geocita maritime. This small ground-dwelling songbird has a short, bird has a short, straight bill. As the name suggests, the grayish minor has gray plumage with hints of brown, buff, and sandy cream. It has no bold markings of any kind. The grayish minor

is a drab little beast, but its coloration helps it blend in with the rocks and sand of its desert habitat. This species and the ten other species of minor compose the genus Geocita. They're all in the family, Furnariadi. Fernaridi, known as the Oven Bird and Woodcreeper family, is an enormous group of neotropical birds, found all across Latin America.

So, these birds are called miners. If you're listening in Australia, maybe you're thinking, oh, minors, yeah, we've got those down here, like the Bell Minor and the Noisy Minor. Except, you know, you'd say it in an Australian accent, like a minor. Well, it's true that there are minors in Australia,

but those Australian miners are not closely related to the miners of South America. Not at all. Anyway, the neotropical miners in the genus Geocita live in arid or otherwise open habitats. They're called miners because they dig tunnels to build their nests in. The grayish miner is found in the otacama at elevations between 1,600 and 10,000 feet, which is 500 to 3,000 meters. But ornithologists know very little about the biology of this bird. For example, it's hard to say what it eats,

especially in parts of the Atacama Desert where there are literally no plants, none. These places look like the surface of Mars. One idea, one hypothesis, is that the miners eat tiny seeds and insects that get blown in by the wind. I'll put a link in the show notes to a video of a couple grayish miners skittering around in the desert. They're pretty cute. You can watch the birds pecking among pebbles and sand on the ground, apparently finding something to eat. What are these crazy little birds doing living in such a hostile, hyper-arid environment? I mean, they've got wings, right?

Can't they just fly away to the nearest lush forest and set up shop there, where the living is easy? Well, apparently not, or they choose not to anyway. Geocita Maritima, the grayish miner, is an extreme example of a bird that thrives in an arid landscape. But it's just one bird species among many around the world that makes its home in the desert. Hello and welcome. This is the Science of Birds. I am your host, Ivan Philipson. The Science of Birds podcast is a lighthearted exploration of bird biology for lifelong learners.

This episode, which is number 92, is all about the value of desert ecosystems as habitats for birds. Deserts are important for the birds that are adapted to live in them. birds that can handle the harsh conditions. There are actually eight bird species with the word desert in their common name. We've got the desert owl, desert lark, desert sastikola, African desert warbler, Asian desert warbler, desert weedier, desert sparrow, and desert finch. But when it comes to other birds, when we ask them what they think about the desert,

they're like, oh heck no, man, that's a hard pass for me. I'm going to stay as far away from that hellish place as I can. The result is that deserts are home to relatively few bird species. Only the polar regions, and maybe some parts of the open ocean, have less bird diversity. Even if a bird species can handle the extremes of heat and cold in the desert, the desiccating winds, and the lack of water, that bird may not find much food. because where there are few plants, there are few invertebrates. So a bird in the desert can have a hard time finding any leaves, seeds, fruit, or bugs to eat.

And yet, an assortment of bird species from many disparate families have managed to carve out an existence in the world's most arid lands. There may be nowhere near as many of them as in, say, a tropical rainforest or a temperate woodland, but the birds we do find in the desert are, I think, a particularly fascinating and admirable bunch. They're tough little buggers. They're resilient. Desert birds have interesting adaptations and behaviors that allow them to survive in places that would kill most other birds in a day. Studying desert birds and the ecosystems they live in feels a little bit like studying life on another planet. Deserts are just that extreme and that different.

In fact, the Otacama Desert has been used by NASA scientists as an analog for Mars. They've been testing lunar landers and Mars rovers there for decades. So again, why does the grayish miner live in a place like that? Why does anything or anyone live in the desert? I guess we could ask the 1.6 million people living in Phoenix, Arizona, you know, that city in the Sonoran Desert where the average high temperature in July is 107 degrees Fahrenheit, which is 42 degrees Celsius, and where the record high temperature is 122 degrees Fahrenheit or 50 degrees Celsius?

Unlike those crazy humans living in Phoenix, birds don't have the luxury of air conditioning or being able to take a dip in the backyard pool. Maybe the evolutionary drive for birds to adapt to the desert is that there are fewer predators to worry about out there and there's less competition for resources. Even if there's not a lot of food or water, as a desert bird, you might have most of it to yourself. And that's just a hypothesis.

And if you're an intrepid scientist looking to make a name for yourself in the world of ornithology, maybe you too would find very few comments. competitors, as in other scientists, if you'd be willing to go out and study birds in the sun-blasted desert. I mean, it seems to me like the lack of knowledge about the grayish minor is probably because of the reluctance of ornithologists. Their reluctance to trudge around in the Atacama desert for weeks on end, looking for a drab little bird. I love the desert and I love birds, but I'm not sure I'd sign up for that job either. And yes, I love the desert. I love the desert.

like a lot. I hope I can spread that love a little bit here today. So let's go ahead and explore the world's deserts and the birds that live in them. The dictionary definition of deserts is a usually sweet course or dish as of pastry or ice cream, usually served at the end of a meal. Wait, that can't be right. Usually a sweet. Oh, I see what happened. I put two S's in there. Desert has only one S. Okay, here we go. A desert with one S is, according to the dictionary, arid land with usually sparse vegetation, especially such land having a very warm climate and receiving less than 10 inches, which is 25 centimeters, of sporadic rainfall annually.

And if we believe what we see in Hollywood movies, then a desert is a place where there's nothing but a bunch of sand dunes, right? And maybe the occasional rock, cactus, camel, or mirage. That's about it. But the real scientific definition is more complex. Scientists describe a desert based on the interaction of precipitation, temperature, and evaporation rate. Precipitation in a desert is, yes, less than about 10 inches or 25 centimeters a year. But deserts also have high rates of evapotranspiration.

Evapot transpiration is an 18-letter word, probably the longest word in this podcast episode. And it means the amount of water is an 18-letter word. that evaporates from the soil, plus the water that gets removed from the soil by plants. In deserts, evapotranspiration significantly exceeds the amount of precipitation received, so there's a water deficit that makes it difficult for most plants and animals to survive. High temperatures increase evapotranspiration, and so do dry winds. There are hot deserts, and there are cold deserts. But even in a so-called hot desert, nighttime temperatures can sometimes dip below freezing.

With little vegetation and low humidity, the heat of a desert just escapes into the sky at night. Extreme swings in temperature between day and night are typical in many deserts. Deserts are dry because they get so little rain or snowfall. The air masses that reach a desert are already dry when they blow in from elsewhere. This can happen in several ways. For example, there are rain-shadowed deserts on the leeward side of many mountain ranges. Moist air blows toward the mountains from the ocean. The moist air is then forced to high altitude by the peaks,

and then the change in pressure causes the moisture to fall out as rain or snow. That precipitation falls on the windward side of the mountains, the side-facing the ocean. As the air mass continues on its merry way down the other side of the mountain range, it has very little water left to give. It's much more dry on that side, so the mountains cast a shadow for the rain, so to speak. For example, Death Valley in the Mojave Desert, as well as the Atacama and Gobi deserts,

are all in the rain shadows of nearby mountain ranges. Just like the many unique forest and grass, grassland ecosystems around the world, no two deserts are the same. Each desert has its own character, its own flavor. This results from its unique combination of geography, precipitation and wind patterns, temperature, vegetation, and animal life. And of course, each desert has its own special collection of bird species. Let's do a quick tour of the world's deserts. And because I tend to talk too much,

quick doesn't necessarily mean quick, but I'll do my best. We've got a lot of ground to cover, literally. This next statistic always surprises me, but here it is. About one-third, 33% of the Earth's land surface is desert. One-third. So deserts aren't some unusual anomalous feature of our planet. They're a major feature. As we talk about these deserts, let your mind fill with all

the colors of these landscapes, colors like burnt orange, brown, rust red, sandy beige, and sun-baked gray. I'm going to give you a rundown of all the major deserts. I'll cover most of the world's deserts, leaving out only a handful of the smaller ones. As we look at these deserts, I'll mention some birds here and there along the way. Because as the host of this podcast, I'm contractually obligated to mention birds at least every 60 seconds. If I fail to do so, well, I shudder to think what the consequences might be. You guys, my listeners might go to Amazon.com to do a rage-fueled search for torches and pitchforks. Ivan doesn't want to talk about birds. Well, I'll show him. Ooh, this torch has 24,000 reviews with an average rating of 4.7.

I'll just add that to my shopping cart. We begin our tour in Africa, because that's where the world's largest desert is. You know it, you love it, it's the Sahara. Spreading across 3.6 million square miles or 9.2 million square kilometers, the Sahara is far bigger than any other non-polar desert. And I'll explain what I mean by polar desert a little later. The Sahara covers almost the entire top end of the African continent. This is a desolate, hot desert.

The summers are blistering, like almost Phoenix, Arizona hot. And the winters in the Sahara are still quite warm. The landscape is a tapestry of dunes, barren mountains, parched gullies and vast stretches of desert pavement. A great example of a bird that lives in the Sahara is the Desert Sparrow, Passer Simplex. This species lives only in the Sahara and nowhere else. The Desert Sparrow is in the same genus as a bird you might be familiar with,

the house sparrow, Passer Domesticus. Both are in the old world sparrow family, Paseridae. The desert sparrow has a pale sand-colored plumage. The male has gray on the back and a black bib and beak. It's a nice-looking little bird. Its habitat includes sand-strewn areas with at least some vegetation, clusters of trees and bushes here and there. You can also find desert sparrows in oases and around human settlements.

Apparently, the semi-nomadic Tuareg people have a fondness for desert sparrows, which they call Mula Mula. The Tuareg consider the birds good luck. Another Saharan bird is the African Desert Warbler, Karuka Desert Eye. This species is very pale, cream and white-colored, yellow-eyed, and, I think it's safe to assume, good-natured. It's a member of the Silveid warbler. family, Silveidi. The African Desert Warbler lives in just the northwestern part of the Sahara. It forages for small invertebrates and small berries in sandy areas with clumped shrubs.

Still on the African continent, we head down south now to the Namib Desert. This is a 1,000-mile or 1,600-kilometer stretch of desert along the southwestern Atlantic coast of Africa. Most of it is in the country of Namibia, which gets its name from the desert. And the desert got its name from the word Namib, which, in the local language, means vast place. But another source says the meaning of Namib is an area where there is nothing. Regardless of what its name means, the Namib Desert is probably, the oldest desert on the planet. Its estimated age is somewhere between 55 and 80 million years. The coastal portion of this desert is mostly sand dunes. Some are almost 1,000 feet high and

20 miles long, making them among the largest dunes in the world. In metric, that's about 300 meters high and 32 kilometers long. The habitat further inland is characterized by planes of gravel and small rocky mountains. Daytime temperatures are super hot, but it can get below freezing at night. Thick coastal fog is common in the Namib Desert, but this region is extremely dry, second only to the Atacama Desert in having very little precipitation. Now, before you start thinking about buying some torches and a pitchfork, let me mention some birds. Some of the more Common species in the Namib include Mountain Weedier, Cape Sparrow, Rupels Bustard, common ostrich, and The Familiar Chat.

Yes, there's a bird named the Familiaria Chat. The dune lark, Kalenjalouda erythroclamus, is a species that's endemic to the Namib desert. This long-legged songbird is plain sandy tan and white all over, with very little in the way of markings. Are you seeing a pattern here with the plumages of desert birds? Many of them, like the desert sparrow, African desert warbler, and the dune lark are colored much like the parched substrates they hop or run around on. Dune larks do indeed spend most of their time in the dunes and other sandy habitats. They find insects and seeds among scattered clumps of grass or by digging in the sand with their bills.

Our tour takes us eastward now into Asia. Our first stop on this continent is the Arabian desert that covers almost the entire Arabian Peninsula. However, the northwestern part of the peninsula is occupied by the small, Syrian desert. Both are extensions of the Sahara. They all form a more or less continuous band of desert that stretches east all the way to India. In the excellent book Habitats of the World, this band is given a more general name, the Palearctic Hot Desert. Some birds are found all across this band of Palearctic hot desert, from Africa to the Middle East to Western or Central Asia. One example is the brown-necked raven, Corvus Ruficalis.

But let's get back to the Arabian Desert. What's it like? Well, it's got enormous areas of sand dunes, as well as contorted rocky ridges and barren mountain outcrops. Animal diversity is pretty low here, but there are a fair number of reptile species and some iconic mammals like the Arabian gazelle and Arabian oryx. There are at least 13 bird species whose common name begins with the word Arabian. Some examples include

Arabian partridge, Arabian bustard, Arabian Eagle Owl, Arabian Green Bee Eater, Arabian Lark, Arabian Babler, and Arabian Grosbeak. Few of these birds are denizens of the deep, barren desert, but most are still what we would call desert birds. Take the Desert Owl, Strick's Hutterumai. Remember that species from the podcast episode I did on Owls? Like so many other desert-dwelling birds, the desert owl also has sand-colored plumage. It's a nocturnal bird, hanging out in rocky gorges, ravines, and in palm groves. It eats small mammals like shrews, gerbils, and mice, as well as insects, lizards, and birds.

One of the birds terrorized by the desert owl is the desert lark, not to be confused with the dune lark I talked about earlier. And the desert lark should not be confused with the Arabian lark either. These three lark species are all vaguely similar looking, yes, but they're not even all that closely related. They're all larks in the lark family, but they each belong to a different genus. In their spare time when they aren't getting eaten, by desert owls, desert larks do things like sing. Here's the song of the desert lark. In my opinion, one of the most beautiful birds of the Arabian desert, well, of the Syrian desert anyway, is the Sinai Rosefinch, Carpodecus Sinoicus. The male has a pink wash on his breast

belly and flanks. The pink is more of a crimson color around his face, around the eyes and lores at the base of the bill. The female lacks any pink color. She's a uniform sandy gray all over. The Sinai Rosefinch is found on the Sinai Peninsula in Egypt, southern Israel, Jordan, and northwestern Saudi Arabia. You'll find these finches in a variety of desert habitats, rocky plains, dry riverbeds, cliffs, gorges, barren mountains, and valley scrub. The Arabian green bee eater is another unusually colorful desert bird. It has a bright blue face, a black eye mask, and sort of lime green upper parts. Continuing eastward, the broad band of Palearctic hot desert eventually transitions into the Thar Desert, which spans the border

between Pakistan and India. That's Thar, T-H-A-R. This desert has plenty of sand dunes and birds like Egyptian vulture, step eagle, and variable wheatier. The deserts further east and north in Asia are classified as cold deserts. These include several deserts in central deserts. These include several deserts in Central Asia, the Taclamakan Desert in Western China, and the Gobi Desert. That's G-O-B-I, not like the fish G-O-B-Y. The Gobi Desert spans north-central China and southern Mongolia. As I mentioned, this is a rain shadow desert. The mountain range casting the shadow is the Himalayas. You don't get a range any more massive than that on Earth. The Himalayas may be a range. make a perfect barrier against most of the rain and snow coming from the south.

Not only is the gobi in a rain shadow, it's also just really far away from any ocean, from any source of precipitation. That's one reason this is a cold desert. Oceans moderate air temperatures, keeping them from getting too hot or too cold. The gobi doesn't get the benefit of any nearby oceans. Also, this desert is further north than hot deserts like the Sahara, and it sits on a high plateau. The elevation is between about 3,000 and 5,000 feet, which is 900 to 1,500 meters. So the winters in the Gobi can be brutally cold, cold and dry, but the summers are still hot. This is the land of the two-humped camel and, in the mountains anyway, the home of the snow leopard. Some characteristic desert birds in

the gobi are palaces sand grouse, the Mongolian ground jay, and the greater sand plover. The sand plover is migratory. In summer, these birds breed in the cold deserts of Asia, like the gobi, but then spend the non-breeding season on sandy or muddy beaches in warm places like East Africa, India, Asia, and Australia. Australia is the one place where I've seen the greater sand plover. It was at the mouth of a river on the coast of Queensland. It was September. The plover was among a bunch of other shorebirds skittering around on the sandy beach. Amazing to think that that bird would spend its next summer way up in the Gobi Desert or somewhere similar. And hey, since we were just talking about Australia, let's go ahead and explore the

deserts there. Australia has a number of regional deserts, such as the Gibson Desert, Tanami Desert, Great Sandy Desert, Little Sandy Desert, and the Itsy Bitsy Sandy Desert. Most people haven't heard of the Itsy Bitsy Desert since, you know, it's so small that it's pretty much impossible to find. Lumped altogether, the most arid parts of Australia are known as the Great Australian Desert. This is the second largest desert on Earth, about one-third the size of the Sahara. There are many habitats within this vast desert complex, low prickly grasslands and shrublands, rocky canyons, dunes, salt flats, and more. A bunch of Australia's bird species are found widely distributed across the continent,

in the desert as well as in less arid habitats like eucalyptus savannas and dry sclerophyll forests. A couple examples are the gala, a pink bird in the cockatoo family, and the budgerigar, aka the well-known budgey parakeet that many people keep as pets. There are some Australian birds that are a bit more adapted for life and dry country. The crimson chat, for example, is a nomadic species that can be found in a variety of desert and semi-desert habitats. The pink-eared duck, too, is a nomadic bird in the outback.

No, I'm not joking. There really is a bird called. called the Pink-Eared Duck, Malico-Korinkus Membranesius. I talked about it in episode 18 of the podcast, which was all about the family of ducks and geese. Pink-eared ducks have a little patch of pink feathers behind each eye. They're really weird and cool-looking birds. They specialize in feeding and breeding in shallow, often-temporary lakes of the outback that fill with sporadic rains. Pink-eared ducks eat by filtering tiny planktonic plants and animals out of the water and mud of their inland lake habitats.

Next up, let's head to the Western Hemisphere, over to South America. We already talked about the Otacama Desert, driest place in the world, grayish minor, yada, yada. The other desert in South America is the Patagonian Desert, also known as the Patagonian Step, S-T-E-P-P-E. I think of this region as something between a full-on desert and an arid grassland. It lies in the rain shadow of the southern Andes Mountains, to the east of those mountains in Argentina. The Patagonian Desert is generally cold, getting what little precipitation it does get in the form of winter snow. The constant wind here is one of the major forces that keep this environment so dry.

A few special birds in the Patagonian deserts are the Patagonian Canistero, Patagonian mockingbird, scale-throated earth creeper, and lesser Ria. The Lesser Ria is a large, flightless bird related to the ostriches. I got in trouble with the Argentinian Border Patrol one time while taking photos of Lesser Rias in the Patagonian Desert. But that's a story for another time. At last we come to North America, the place where I keep all my stuff. This continent has several distinct deserts.

To keep things simple, we'll say that there are three hot deserts in North America and one cold desert. The largest of the hot deserts is the Chihuahuan Desert, spanning north central Mexico and parts of Arizona, New Mexico, and Texas in the U.S. This is a shrubby, grassy desert. It has hot summers with some monsoon rains, but winters are cold and dry. To the west lies the Sonoran Desert, which is my personal favorite. It covers parts of Southern California and Arizona, as well as the Mexican regions of Baja, California, and Sonora. This is North America's hottest and yet most lush desert. Many of its plants green up and bloom in late summer after being doused by monsoon rains.

Summers in the Sonoran Desert are blazing hot while winters are mild. This is a spiky, thorny, prickly place. It's the home of the cactus. There are over 200 cactus species here, including the iconic and world-famous saguaro. You may have heard of a lizard called the Gila Monster. That's Heela spelled G-I-L-A. This is one of the world's only truly venomous lizards. And what an awesome name, right?

Heela Monster. Are there any other animals out there with an official name that includes the word monster? Not that I know of. Well, in the Sonoran Desert, there's also a bird called the Heela Woodpecker, Melanerpe's Europygealus. It's got a tan-colored head and underside and bowl. black and white barring on the back and wings.

Males have a red patch on the crown. The Gila woodpecker is the world's only truly venomous woodpecker. It hunts for small children who get lost in the desert at night, using its special infrared heat sensors. The bird waits for just the right moment, and then it strikes with its venomous beak, piercing the soft flesh of its hapless prey. Nah, I'm just kidding. Don't worry, kids. There are no terrifying monster woodpeckers out there. Gila woodpeckers are totally chill and totally non-venomous. But what if? These woodpeckers excavate their nongoves. These woodpeckers excavate their nest holes in trees and large saguaro cactuses. Those holes are often used later as nesting sites

by other birds, like elf owls and brown-crested flycatchers. The next desert on our list is the Mojave. It lies mostly within the borders of southern California and southern Nevada. The sprawling city of Las Vegas is in this desert. The Mojave is North America's smallest and dry desert. And in case you don't know, Mojave is spelled M-O-J-A-V-E. Summers here are hot, while winter temperatures can drop below freezing. I lived in the Mojave Desert for a few years when I was a kid. During one particularly severe winter, I remember building snowmen with my friends and having snowball fights. School was closed for two weeks, and it was glorious. One icon of the Mojave Desert is the Joshua Tree, a giant species of yucca in the asparagus family. Maybe you've heard of

Joshua Tree National Park. So those are North America's hot deserts, the Chihuahuan, the Sonoran, and the Mojave. The cold desert we have here is the Great Basin, occupying most of the state of Nevada. This desolate desert lies in the rain shadows of both the Sierra Nevada and the Rocky Mountains. It has a more northerly latitude than the hot deserts I just mentioned, and it sits at a relatively high elevation. So the Great Basin Desert experiences extreme temperature swings between summer and winter, and sometimes between day and night. Many North American desert birds can be found in more than one of our deserts. Examples include the Greater Roadrunner, Blackthroated Sparrow, Gamble's Quail, Cactus Wren, Verdon, and Phano Pepla.

The Pheno what now? The Phanopla, P-H-A-N-O-P-E-P-L-A. Males of this songbird species are glossy black with a spiky crest and red eyes. Phanopepla is the common name, but it's also the genus name for the species. It's in a silky flycatcher family, Tileogenatidae, which is most closely related to the waxwing family. Phenopeplas specialize in eating the berries of mistletoe plants. The berries provide most of the water of phenopepla needs, so the birds rarely have to drink. Another desert bird that can go for long periods without drinking is the black-throated sparrow,

Amphespiza bilineata. This is a really handsome little sparrow. It has a gray head, black throat, and crisp white stripes running over the eye. and along the mailer line. Mailer as in the lower edge of the cheek. The body is light brown on the back and mostly white underneath. Blackthroated sparrows feed on the ground, where they search for insects like grasshoppers as well as seeds. I've seen these birds hopping around on islands in the Sea of Cortez,

islands that are in the Sonoran Desert. The sparrows on these islands have pretty much no access to fresh water. Amazingly, they can survive on dry seeds alone. You might be more familiar with birds like the Greater Roadrunner and Cactus Wren. I talked extensively about roadrunners in episode 34 of this podcast, so check that out if you'd like to learn all about roadrunners. The Cactus Wren, Campilorincus Brunea Capillus, is the state bird. of Arizona. The nest of a cactus wren is a messy-looking, globe-shaped thing with a side entrance tunnel.

Constructed with dry grass and twigs, it's often tucked in among the wicked spines of a cactus. Not a bad way to prevent your eggs and chicks from being eaten by ground-dwelling predators. And just like that, we've covered all the major deserts of the world in Africa, Asia, Australia, South America, and North America. Well, we've covered all the non-polar deserts, the ones that fit our normal understanding of what a desert should look and feel like. But remember earlier when I mentioned that there are polar deserts? If we define a desert as a place where precipitation is less than 10 inches or 25 centimeters per year, then that means the polar regions are also deserts.

This includes vast portions of the Arctic in Canada and Russia and most of Antarctica. Polar deserts have essentially no plant life, because they're so barren and so cold they can support very few bird species. parts of Antarctica rival the Atacama Desert for being insanely dry, as in like the driest place in the world. And you know that I'm tempted to talk smack about Antarctica here, as I so often do, but I'll just bite my tongue. Next time, Antarctica, next time. Now let's consider the unique challenges faced by birds in the day. desert. And let's talk about some adaptations and behaviors desert birds have that help them

survive. At some point, I'd like to do an entire podcast episode on the adaptations of birds to hot and dry environments. So today we'll just do an overview. If I were to survey a classroom full of third graders, asking them what makes life hard for a bird in the desert, they'd probably come up with all the right answers. They'd say that the desert is hot, and there's no water, and there isn't much food. So let's consider each of these challenges. The desert is hot, yes, quite often, but some deserts can be bitterly cold at times, so birds may have to deal with both temperature extremes, sometimes over the course of a single day. But let's go ahead and focus on heat, since that's what we associate with most deserts.

To avoid overheating, desert birds seek shade, and many of them are most active in the cooler morning or evening hours. Some species avoid the heat by being nocturnal. These are all things that you or I would probably do to beat the heat. They're intuitive. But birds have an advantage that we don't have. They have higher body temperatures. The core body temperature of birds ranges from about 102 to 109 degrees

Fahrenheit, which is 39 to 43 degrees Celsius. That's pretty toasty. If your core body temperature is closer to the air temperature around you, you're not going to overheat as easily. We humans sweat when we need to cool down. As the sweat evaporates from our skin, it carries heat away from our bodies. Well, birds can't sweat because they don't have sweat glands, but they can still take advantage of some evaporative cooling. They do this by panting. As air moves in and out of a bird's open mouth and lungs, moisture evaporates, and that cools the bird down. Some birds also have a behavior called Guler Fluttering. This is a rapid vibration of the thin skin of the throat region, known as the Guler Pouch or Guler Skin. Guler Fluttering helps to increase the effect of

evaporative cooling. Bird eggs and nestlings are especially vulnerable to extreme temperatures. They need to be protected. A brooding parent can use his or her body to shield the eggs or chicks from the sun and the hot air. Many desert birds build their nests in the shade of vegetation or in burrows. That's what the grayish miner does, right? Underground burrows can be much cooler than the surface. Nests and burrows offer the added advantage of being hidden from many predators. The second major challenge in the desert is the lack of water, or at least the very limited availability of water. Most birds can fly, so they have the ability to search the desert landscape far and wide for far-flung water sources. But flying takes a lot of energy,

and it increases body temperature, so there's a trade-off there. Some desert birds have adaptations for keeping what water they drink inside their bodies for as long as possible. In other words, they have adaptations for conserving water. Birds lose less water in their waste products than mammals do. Mammals excrete urea as a waste product, and this toxic chemical needs to be diluted in a lot of water. So mammal urine, mammal pee, is mostly water. Birds, on the other hand, excrete their corresponding waste as uric acid.

Uric acid excretion doesn't require nearly as much water as urea excretion. So bird urine is highly concentrated. That's the white pasty part of the poop that birds like to drop onto your freshly washed car. Birds lose much more water by evaporation through their skin, mouth, and respiratory passages than they do through their feces. This effect is especially strong for small birds because a small bird has a large skin surface area compared to the volume of its body. If water in the desert is so hard to come by and it's easy to lose the water in your body because of the heat and dry air, maybe the best thing to do is just stop drinking water. That sounds crazy, but it's exactly what some desert birds have evolved to do.

As I mentioned earlier, birds like black-throated sparrows, phana peplas, and cactus wrens can go for long periods without drinking any water. They get the water they need from their food, whether that's berries, seeds, or insects. And speaking of food, that's our third major challenge. Deserts in general have few plants and low overall productivity in terms of biomass. That means there's just less to eat all around. Birds can adapt to the scarcity of food in multiple ways. For example, they can specialize in eating something that is fairly abundant.

For example, the phenopepla eats the berries of mistletoe plants. These parasitic plants, such as the mesquite mistletoe, are abundant in the deserts where phenopeplas live. An alternate strategy is to be omnivorous, eating whatever you can find. The greater roadrunner is famously omnivorous and, opportunistic. This bird will eat insects, scorpions, spiders, centipedes, frogs, lizards, snakes, birds, eggs, rodents, carrion, and cactus fruits. If food is limited in deserts, that means that food energy is limited. Desert birds may have less energy available for

reproduction, for making baby birds. So some of them lay smaller clutches of eggs compared to similar birds in habitats with more food and water. Laying fewer eggs is one way to conserve energy and water and still have a chance of successfully raising a family. In years when water and or food are particularly scarce, some desert birds forego breeding altogether. They just conserve their energy and wait until next year when conditions will hopefully be more favorable. One approach for surviving in the desert is to just move around, continually seeking places where there's some food and water. If you can take advantage of random temporary sources of water, food, and shelter, you don't necessarily need other fancy adaptations to survive. This is what nomadic birds do. They fly

around in the desert, often in large flocks, landing here and there, wherever they can find resources in abundance. This works well when rainfall and food availability across the land is unpredictable. As I mentioned, this is the approach taken by many birds in the outback of Australia. Birds like the Crimson Chat, Pink-Eared Duck, and Budger-rigar are nomadic. Their movements track changing environmental conditions. They feed and breed in different places each year, depending on where the food and water is. Other birds are migrants, spending only part of the year in the desert.

They head elsewhere during the driest, hottest, or coldest seasons. The example I gave earlier was the greater sand plover of the Gobi Desert. So we've got birds that tough it out as year-round residents in the desert. We've got other birds that are nomadic and some that are migrants. There are also bird species that eke out a living in pockets of relatively comfortable habitats that are surrounded by desert. On the top of an isolated desert mountain, for example, where there's more precipitation and cooler temperatures. Or there's the relatively lush vegetation growing along desert streams and rivers, what we call riparian areas. Such places offer plentiful water, food, and nesting sites.

A good example here is the oasis hummingbird, Rhodopsis Vesper, of South America. It lives in the Otacama Desert and surrounding arid scrublands. More specifically, the oasis hummingbird lives in patches of greenery and moisture, in riparian thickets, in scrub habitats along the ocean shore where there's lots of fog, in agricultural areas, and in backyard gardens. So, it's possible that the oasis hummingbird doesn't have any special adaptations for surviving in an extremely arid environment. It can live in the Atacama Desert only in isolated oases, where the conditions are relatively cush.

I really hope you're enjoying the episode so far. Maybe this is your first time listening to the Science of Birds podcast. Or maybe you've listened to every episode twice. It's a serious joy and an honor for me to write and produce these episodes for you. One of the main reasons I can keep doing this is because of my supporters on Patreon. So think about joining me on Patreon as an exclusive member and you can support the podcast and get insider-only updates from me like posts and videos. There are several tiers of support, each with its own benefits.

For example, at the helpful Hornbill tier and above, you get behind the scenes content from me, like videos where I share my deep thoughts about birds and who knows what. Members at all paid tiers get to vote in polls. For example, I recently polled my members asking them to choose which bird species the next episode is going to be about. I'm a little surprised at the poll results, but hey, that's democracy in action, yo. As a member, you can also connect with me through the community chat on my Patreon page. and you can send me direct messages through the app. I'm so grateful for the support of my listeners

who've joined my Patreon community. If you'd like to join the fun, there's a support the show link in the show notes for this episode. Or you can simply go to patreon.com slash science of birds. That's patreon.com slash science of birds. Now I want to highlight a few groups of birds that are well known as desert dwellers.

First up, we have the sand grouse. These are the 16 species in the family, Teroclady. That's got a silent pee at the beginning, Teroclody. Despite the name, sand grouse are more closely related to pigeons and doves than they are to grouse. All sand grouse live in the old world, in Africa or Eurasia. These are beautiful birds with creamy tan or gray bodies and intricate geometric patterns decorating their backs and their wings.

Unlike black-throated sparrows and cactus wrens, sand grouse need to drink water regularly. Every day they fly for tens of miles to gather in large flocks at reliable water sources. They take just a few seconds to fill their bellies. Some sand grouse species drink in the morning, others in the evening, and a couple drink at intermediate times. Here's the sound of some chestnut-bellied sand grouse in the Arabian desert of Oman.

They're calling in flight. Again, that was the chestnut-bellied sandgrouse. Perhaps the biggest claim to fame for sand grouse is the fact that adults carry water to their chicks. Males in particular have specially adapted feathers that are super absorbent for this purpose. After flying up to 20 miles from the nest, the daddy sandgrouse wades into a pool of water and rocks his body back and forth. His unique belly feathers have a microscopic structure that is great for absorbing water. After about 15 minutes, the male has soaked up about two tablespoons of water and off he flies. The thirsty chicks waiting back home will have enough water to survive another

day. This is a pretty amazing adaptation to arid environments. And you know, this gives me an idea for a new product, a product that's going to make me a millionaire! When I need to clean up spills around the house, I use paper towels made out of sand grouse feathers. That's right, feathers from the belly of a male sand grouse. Sand grouse towels are two times more absorbent than the leading ordinary brand. And they're great for when my kids are thirsty on a hot day. I just soak up some water in a sand grouse towel, then wring it out into the gaping mouth of my obnoxious child. Our next group of desert birds is the ground jays. They're in the crow and jay family, Corvidi, and are the only members of the genus Podocesee. There are four Ground Jays species.

Ground Jays live in deserts and semi-deserts. They run around on long legs and dig in the soil with their down-curved beaks. The Mongolian Ground J, Potocese-Henderson Eye, also known as Henderson's Ground J, is an attractive bird. It's a sandy cream color overall, but with a black crown, bill, and inner wing. The outer primary feathers on the wing are white. In flight, the wings flash with that bold contrast of black and white. Mongolian ground jays live in Central Asia. Their primary habitat is expansive areas. of flat gravel in the gobi desert and in the surrounding dry ecosystems.

Ground jays in general are omnivores. They rarely fly, preferring to forage on the ground for beetles and other insects, lizards, seeds, and other plant material. Then we have the weed ears. There are about 38 weed ear species belonging to two genera. They're songbirds in the old-world flycatcher family, Musca Capidae. Wheatiers have an upright posture like many other members of their family. Their plumage patterns are bold with some combination of black, white, gray, or buff, varying from species to species.

Most weed ears have a bright white rump patch above the base of their tail. This flashes conspicuously when you see the bird flying away from you. Open, barren, rocky habitats are the places that weeders like to hang out. Some species live high in the mountains, others in the Arctic tundra. And, of course, there are some weed ears found in deserts. The mountain weed ear, for example, lives in the Namib Desert and the surrounding grasslands. A bird more specialized for life in hot deserts is the white-crowned weed ear. It lives year-round in the depths of the Sahara, Syrian, and Arabian deserts.

Then we have the desert weed ear, Enanthi Deserti. This species has a distribution that spans the entire band of Palearctic hot deserts and even beyond into the cold deserts of Central Asia. When I did a quick search on the website I Naturalist, I found that six species of weed ears have been recorded in the heart of the Sahara Desert, including the Desert Weedere. In that same swath of the Sahara, I found I Naturalist records for nine lark species.

This is the last group of birds I want to tell you about today, the larks. The name of the lark family is Allaudity. Each of the bird groups I'm talking about here will probably get their own podcast episode someday, and that's definitely true for larks. Like weed ears, larks are birds that prefer open country. A number of them have adapted to life in the desert. That includes, of course, the desert lark,

Amomani's desert tie. This bird wears the standard-issue uniform of a desert dweller, non-descript plumage that's a plain, grayish-brown overall. Desert larks eat small seeds and insects in rocky hills or on rocky slopes. They range from the Sahara in the west all the way to the Thar Desert in India. A desert lark will drink water when water is available, but it can go without drinking if necessary.

Last we have the Greater Hupu Lark, a leman alaupis. This species has a similar distribution as its cousin, the desert lark. But the greater hoopu lark occurs in flat, sandy, or gravelly areas, rather than on rocky slopes. The greater hoopu lark is a large, stretched out, out-looking lark, with extra long legs and a long, curved bill. Here's the unmistakable song of this lark, recorded in Morocco.

There was a study on larks in 2005, published in the journal Bioscience. The paper's title is Physiological Adaptation in Desert Birds. The researchers compared four desert-dwelling lark species, including the Greater Hupu Lark, with lark species living in semi-arid habitats and temperate habitats. This study revealed that desert-dwelling larks have some special adaptations for surviving in dry environments.

Compared to larks living in Europe, the ones living in the Arabian desert have lower metabolisms and lay fewer eggs per clutch. So these are adaptations for conserving energy. The several species of desert-dwelling larks also conserve water by losing less of it through their skin. The fats or lipids in the skin of birds like the Greater Hupu Lark have a modified molecular structure that reduces water loss through evaporation. Deserts are tough places to live. As a result, bird species diversity in many deserts is relatively low.

But it seems to me like the birds we do find in the desert are all the more interesting and special. They're survivors. The evolutionary adaptations they possess are. are impressive and fascinating. Desert birds are unique representatives of avian biodiversity. This is just one reason I think they deserve to be protected. But desert habitats aren't always easy to protect. Because deserts are also tough places for people to live, many of us tend to think that they have less value, less intrinsic worth than other greener places. Deserts are often written off as barren wastelands. And the degradation of deserts by human activities has only

perpetuated this stereotype. Humans have disrupted desert ecosystems in many ways. These include failed attempts at agriculture, land clearance, road construction, off-road vehicle use, water diversions, grazing by livestock, and fires intensified by invasive grasses. Because precipitation and plant productivity are so low in deserts, it takes these ecosystems an extra long time to recover from disturbances like those I just listed. And then there are the effects of human-caused climate change. Deserts around the world have been getting drier and hotter

over the last 50 years, more so than most other ecosystems. A study published in 2018 in the journal PNAS looked at bird surveys conducted in the Mojave Desert over 100 years. Over 50 survey sites were scattered across Death Valley and Joshua Tree National Parks, as well as the Mojave National Preserve. These are public lands with some of the highest levels of conservation protections. And yet, the data in this study revealed that over the last century, the survey sites have lost 43% of their bird species on it.

average. The primary culprit for this catastrophic loss of avian diversity is a decrease in precipitation. And that decrease in rainfall and snow is a symptom of climate change. It is climate change. So in some ways, desert birds may be especially vulnerable as the world warms up, compared to birds in other environments. Many desert birds already live at the edge of what's physiologically possible? How much further can we push them before they reach a breaking point? How about we don't find out? Let's not push them that far. And hey, I know this climate change and conservation stuff can be kind of a downer, but I'm sure you agree it's important that we talk about it. But anyway, deserts are rad, am I right? I mean, have you ever experienced a joyful day

of birding in the desert, in the Australian outback, in the hills of Morocco, or maybe a even more exotic location like the outskirts of Phoenix, Arizona, or Las Vegas. If you have, you can probably appreciate how surprisingly rich such environments can be, and you can imagine how important they are for the birds that call them home. And if you have not yet discovered the magic of the desert, I invite you to get out there ASAP. Stop whatever. you're doing, find your nearest desert and go see what's out there. Larks, weed ears, roadrunners, sand grouse, wrens, sparrows, phana peplas. Who knows what awesome birds you'll find? But seriously, watch out for those Gila woodpeckers. I'm still not sure about those guys.

That about does it for this episode on Deserts. I hope you enjoyed learning a little about these habitats and about desert birds. Putting this episode together has really inspired me to get back to the desert as soon as I can. My most recent desert experience was a few months ago. I was in Southern California visiting my mom for Christmas. I was out birding in the Sonoran Desert one morning, and it seemed like every bush had a glossy black male phenopepla perched at the top. Like the star on top of a Christmas tree.

But, you know, way better. I want to give a shout out to my newest supporters on Patreon. Welcome Katie Patterson, Janice Valdez, Mambo, Jacob Peters, and Mary Simon. I deeply appreciate your support. Thank you all so much. Again, if you'd like to support the podcast as a member, just go to patreon.com slash science of birds. You can also send me an email if you have something you'd like to share with me, like maybe an experience you had with birds in the desert.

or your favorite dessert recipe. Whatever it might be, my email address is Ivan at Scienceofbirds.com. This is episode 92. You can check out the show notes for the episode, along with some hand-selected photos of species I talked about today on the Science of Birds website, Scienceofbirds.com. This is Ivan Philipson, wishing you an awesome day. Peace.