Latest / Okay, But... Birds / Okay, but how do birds handle a heatwave?
Transcript
- 0:00Coming up on this episode of OK But Birds.
- 0:02They breed during the summer and they actually cool their eggs.
- 0:06Wow.
- 0:06They actually evaporate water to lower their body temperature and cool their eggs so the eggs don't exceed a lethal temperature for the embryos.
- 0:54Europe has been really hot lately.
- 0:56So is North America.
- 0:57Broadly, 2026 is shaping up to be the hottest year the United States has experienced in its 250 years.
- 1:04If we're lucky, we retreat into air conditioning.
- 1:06Birds don't have that luxury.
- 1:08They're outside in the heat.
- 1:10I personally prefer being too cold to being too hot.
- 1:12Maybe it's the Canadian in me.
- 1:14A couple of years ago on my first sabbatical, I was working in Panama with my friend and collaborator, Jay Falk.
- 1:19During that trip, we discovered that white-necked Jacobin chicks mimic venomous caterpillars, but that's a topic for another episode.
- 1:26Rarely in my life have I felt panic over how hot I was, but in the rainforest of Gamboa, I got that hot.
- 1:32I was still sweating, which was a good sign, but I was genuinely worried about cooling down.
- 1:36At 100% humidity, sweating barely works.
- 1:39The sweat doesn't evaporate, so you don't get the benefit.
- 1:41You're just hot and sticky.
- 1:43It's the worst.
- 1:44Thankfully, Jay's house had a pool, and after our hikes, we could sink into water at least a little cooler than we were.
- 1:51Living in Colorado now, I'm regularly too hot in the summer.
- 1:53But here, where humidity rarely tops 40%, sweating cools you down all the time.
- 1:58I still remember noticing that a cold glass of water barely sweats out here.
- 2:02It's just that dry.
- 2:03And that's the thing about sweat.
- 2:05It only saves us because we can make so much of it from glands all over our skin.
- 2:09Plenty of other mammals sweat too, but for most of them, all that fur gets in the way.
- 2:12So evaporating sweat off the skin isn't always the most efficient way to cool down.
- 2:16So what about birds?
- 2:18They don't sweat at all.
- 2:19Which brings us to the topic of today's episode.
- 2:21Okay, but how do birds handle a heat wave?
- 2:24To find out, we'll talk to Dr. Blair Wolf, a professor in the Department of Biology at the University of New Mexico, who spent his research career studying exactly this.
- 2:32After the break, Blair walks us through the impossible choice birds face between overheating and drying out.
- 2:38Why some backyard birds sail through the heat that kills others.
- 2:41And what birds dying in these heat waves tell us about what's coming.
- 2:44Stay tuned.
- 2:50Well, welcome back to the podcast, everyone.
- 2:51I'm really excited to have Blair with us today.
- 2:53Thanks for joining us, Blair.
- 2:55Yeah, absolutely.
- 2:56So when it gets, you know, over 90, I start panicking, but you know, it regularly gets over a hundred in many places in North America and the world.
- 3:04And so as humans, we shed layers, we sweat, we might find AC, drink some cold water, but birds can't do most of those things.
- 3:12So what are birds doing to keep from getting too hot?
- 3:15I mean, birds are sort of, first of all, they're sort of pre-adapted to these high temperatures because they have a very high body temperature.
- 3:22Body temperatures run anywhere from 104 is sort of the baseline or 41 degrees Celsius all the way up to 48 or 118 degrees in a living bird.
- 3:33Wow.
- 3:33Functioning normally.
- 3:34Wow.
- 3:34That's crazy.
- 3:35Humans are long dead, right?
- 3:40At 107 to 108, 109, you're gone.
- 3:43You're dead and that's it pretty much.
- 3:46And so birds have this pre-adaptation with high body temperatures maybe associated with flight.
- 3:54That provides a more favorable gradient for dumping heat.
- 3:58The means of last resort for birds and humans is evaporative water loss, right?
- 4:04Evaporative cooling, we call it, where the animal is actually evaporating water from some surface of its body to cool its body, right?
- 4:12Yeah.
- 4:14Evaporative heat loss in birds, in perching birds, in songbirds, it generally comes from panting, movement of the respiratory tract, right?
- 4:24Like dogs, they're dumping heat by evaporating water from the surfaces of the lungs and throat.
- 4:30That carries heat away, and so they cool that way, and that reduces body temperature or reduces the heat load on the animal.
- 4:38The other way birds cool is there are some birds, like doves...
- 4:43that can actually have every water across the skin.
- 4:45Oh, really?
- 4:46I didn't know that.
- 4:47That's unusual.
- 4:48They don't have skin glands.
- 4:49You know, birds have very thin skins.
- 4:52They don't have glands in the skin for the most part, right?
- 4:56Yeah.
- 4:56And so we're not... Just one, really, right?
- 4:59Just the uropidial gland, right?
- 5:00The preen gland.
- 5:01Yeah.
- 5:01Yeah.
- 5:02So that's the only one I know about.
- 5:04They somehow change the permeability of the skin and dump huge amounts of heat.
- 5:09And so doves are unusual in that they're able to dump huge amounts of heat, doves and pigeons, right?
- 5:15Huge amounts of heat across the skin.
- 5:17And that may, you know, they may be the flying cockroaches of the world as the world continues to warm.
- 5:25Right?
- 5:25They'll be the only thing left here.
- 5:27And there's sort of a third group that uses a process called guler flutter.
- 5:32Goat suckers, the poor wills, the night hawks, those kinds of birds actually flutter to their throat, their hyoid apparatus.
- 5:38And this is a very, very efficient mechanism of dumping heat.
- 5:43These poor wills nest on the ground.
- 5:45They lay a white egg.
- 5:47They nest under creosote bushes where they're sitting on the ground, potentially exposed to high solar heat loads.
- 5:55And the ground temperatures are very high as well because of the absorption of solar radiation.
- 6:01So they're sitting on the ground and, you know, nesting during the spring when it's still really, really hot.
- 6:10Do you think they're also trying to keep their eggs cool then?
- 6:12That's why the egg...
- 6:14Is white.
- 6:15I would think that, but nobody's demonstrating egg cooling in them.
- 6:19I think they also shuffle and move their egg to follow the shade sometimes.
- 6:24So they'll shuffle the egg along, I think.
- 6:26Nice.
- 6:28That's not well documented, but I think it's also the only bird that hibernates.
- 6:33Yeah, I was just going to say, poor whales are these birds that have come up now a few times on the podcast.
- 6:38Yeah, they're super cool.
- 6:39The hibernating piece is fascinating that they're the only bird that hibernates and they do this guler fluttering to stay cool.
- 6:46So they can kind of be at both ends of this insane spectrum.
- 6:50That would kill your eyes.
- 6:51Yeah, no, it's a...
- 6:52It's a really neat bird.
- 6:54It's a really cool bird.
- 6:55Very cool birds.
- 6:56The fact that birds have such high body temperatures, I knew that, but I didn't know how high they could be and still function.
- 7:02Is a typical bird on a typical summer day have that really, really high body temperature?
- 7:07Do they only raise their body temperatures to avoid having to try to cool themselves down in really high heat scenarios?
- 7:14Yeah.
- 7:15So most birds are running in the 40s, just as their baseline.
- 7:19We run at 37, right, as our baseline.
- 7:23In birds, it appears that body temperature is very labile.
- 7:26It moves up and down quite easily.
- 7:29And in part, that may be associated with flight and muscle efficiency.
- 7:33When birds fly, body temperatures go up typically.
- 7:37even though they're cooling as they move through the air.
- 7:40So body temperatures in birds seem to be very labile, right?
- 7:43They can move quite a bit.
- 7:45And one of the things that birds do is by having body temperature rise as it becomes hotter and hotter, that provides still a more favorable gradient for dumping heat without using water.
- 7:58Right, yeah.
- 7:58birds have to balance both water and energy budgets over very short timeframes, hours to days for small birds, right?
- 8:06Yeah, totally.
- 8:07So you can pant and cool down through evaporative water loss, but you're losing water, which is usually not a good thing, especially if you're a desert living creature.
- 8:16Or you can hold on to your water and potentially overheat.
- 8:20So how do birds transition between these things?
- 8:23What drives those trade-offs?
- 8:24And are there any particularly interesting birds in that context?
- 8:28Yeah, so this is a real tradeoff problem, right?
- 8:30And so, especially for birds in deserts where they are subjected to real large heat loads from the external environment, right?
- 8:38If their temperature in Phoenix is 118, that's going to be above the bird's body temperature.
- 8:44Yet there are thousands, if not millions, of birds living out there under those conditions.
- 8:48Yeah.
- 8:49And they have to make it every day.
- 8:50Yeah, it's impressive.
- 8:51They don't just have a drinking fountain they can go to and tank up on water, right?
- 8:56And so they have to be mindful of their body water content, you know, how dehydrated they are, versus because that affects performance, right?
- 9:07In humans, we lose a liter of water, and that actually affects our heart rate.
- 9:14Two liters, it's significant.
- 9:16It actually affects your running performance, things like that.
- 9:19And so one to two percent of water loss in humans really starts to produce a deficit in function, right?
- 9:25And so it affects our performance.
- 9:29Well, birds have to perform every day, right, at their maximal level.
- 9:34Every bird is an Olympic athlete.
- 9:36If you had Nate Center on there or Maria, they're talking, these birds are all Olympic athletes, right?
- 9:43Everyone in the population is that well-trained to that level of fitness, right?
- 9:49And so this trade-off with the heat is...
- 9:52You either evaporate water to stay cool and keep your body temperature below lethal limits, right?
- 9:58So you don't heat stroke out or you don't and you allow body temperature to rise.
- 10:06Now, there are limits to that, and so any limits on body temperature like that in the heat are really going to limit the animal's activity.
- 10:14And so you can't go flying around in that kind of heat.
- 10:17You can't be exposed to solar radiation in that kind of heat because exposure to solar radiation is equivalent to increasing the air temperature of a room by 10 or 12 degrees Celsius.
- 10:27Yeah, yeah.
- 10:28You know, 20 degrees Fahrenheit.
- 10:30And so if the room is already at 120, you expose the animal solar radiation, now it's equivalent to 140 degrees.
- 10:38And so what happens to evaporative water loss as air temperature increases?
- 10:43Well, evaporative water loss increases what we call exponentially.
- 10:46It's not a straight line.
- 10:47It's a curve.
- 10:48Mm-hmm.
- 10:49And so the animal may go from losing 1% or 2% of body mass per hour by evaporating water just to stay cool at, say, 40 degrees Celsius.
- 11:00At 48, it may be losing 5% or 7% of its body mass an hour.
- 11:05For a small bird like a bird and black-throated sparrow...
- 11:12or something like that.
- 11:13And so no animal can lose 7% of its body mass per hour for a very long time without becoming a little freeze-dried, you know, piece of beef jerky or something, you know, bird jerky.
- 11:26Bird jerky, yeah.
- 11:28Humans, it's sweating.
- 11:30We can use maybe 12 liters a day, you know,
- 11:34three or four gallons of water a day just through evaporative e-loss.
- 11:38So we're very, very good and effective at cooling, but we've got to stay hydrated.
- 11:43So this old idea, hydrate or die, is true for birds.
- 11:47And so both doves and quail are tied to water.
- 11:52And so they both fly to water or move to water every day, basically, sometimes twice a day.
- 11:59And so at least doves have this huge cooling capacity.
- 12:03And we've exposed doves to, you know, 140, 150 degrees, and they've been just fine.
- 12:08Wow.
- 12:09What species of dove could take 140 degrees?
- 12:13White wings and morning doves.
- 12:16Morning doves even.
- 12:17Wow.
- 12:17I think most people think morning doves are these like common backyard boring birds, but they can persist at temperatures that high.
- 12:25Yeah.
- 12:25Wow.
- 12:26Yeah.
- 12:26How does that work?
- 12:27I mean, I think of like we have sweat glands and the sweat is released and then evaporative cooling happens.
- 12:33But what's the deal with dove skin?
- 12:35Like what's the physiological mechanism there?
- 12:37That's been of interest to cosmetic companies.
- 12:41Birds are thin-skinned, so they may actually change the lipid structure of the skin and the blood flow to the skin to make the skin more permeable to water.
- 12:51But that's still an open question.
- 12:53Oh, that's cool that it's still an open question, but it's clearly a very effective way to live at very high temperatures.
- 13:00Right.
- 13:01And they only pant at when they're really eat stressed, right?
- 13:05And so they can pant as well.
- 13:07And so, but they're, again, they're losing so much water.
- 13:10And in doves, you'll often see a white-winged dove nest or a mourning dove nest.
- 13:16I have one in my yard where the adult bird is just sitting out in the open on top of a cactus, exposed to the sun's radiation.
- 13:24So it's sitting out there.
- 13:25It's 105.
- 13:26Uh-huh.
- 13:27Yet it's got deep load from the sun and it just sits there.
- 13:31Not moving, not panting, not doing any evaporating water.
- 13:34Wow.
- 13:36And the doves change once a day.
- 13:37The adults change once a day.
- 13:39I forgot whether the female incubates at night and the male during the day.
- 13:43Oh, cool.
- 13:44But, you know, and doves are interesting from this standpoint that they breed during the summer.
- 13:50They're exposed to solar radiation, and they actually cool their eggs.
- 13:53Yeah, yeah, because they can't.
- 13:54They actually evaporate water to lower their body temperature and cool their eggs so the eggs don't exceed a lethal temperature for the embryos.
- 14:03Yeah, a reverse problem to the chickadees here in Colorado that are just trying to keep their eggs warm.
- 14:08Yeah.
- 14:08Yeah.
- 14:12When heat waves hit, what are we seeing in terms of bird survival or mortality or reproductive impacts?
- 14:19And what do you think we should still be looking at?
- 14:21There's both acute effects, what happens right now on a daily basis and whether birds survive through the day, right?
- 14:27Right, yeah.
- 14:28And so we already know that heat waves, which are increasing in frequency, so they're happening more frequently,
- 14:36The duration is longer.
- 14:37Instead of three to five days, maybe you have seven or eight days where a high-pressure air system stays over an area and just burns it, right?
- 14:45Yeah.
- 14:45And then they're just going to become more and more frequent as well and higher in their temperatures, right?
- 14:52And so we're on a trajectory for warming right now.
- 14:57We're probably looking at three to four degrees Celsius by 2100.
- 15:01Wow.
- 15:02Are we seeing mass die-offs in birds?
- 15:03Like, what are birds telling us about heat waves, what we're about to live through?
- 15:07I mean, you know, France just experienced an unprecedented heat wave.
- 15:11We're experiencing hot weather here in North America as well.
- 15:14I mean, birds, the canary in the coal mine is a real metaphor because canaries would die before people would.
- 15:20Yeah.
- 15:22What are we learning from birds in the context of just heat waves and their broader impacts?
- 15:28I think some of it's pretty subtle, right?
- 15:30Because there's no idiots walking around out in the desert when it's 120.
- 15:34Yeah, so we wouldn't find them if they were dead, yeah.
- 15:36Yeah.
- 15:37How do you survey bird populations?
- 15:38You know, so it's only where you have birds in large numbers that around humans that you see them.
- 15:44And sort of Australia is sort of the poster child for this.
- 15:47Yeah.
- 15:48Right.
- 15:48I've documented some die-offs in 2010 and going forward of things like budgies where there's thousands of budgies under a carport.
- 15:59And next thing you know, there's thousands of dead budgies just from acute heat stress, meaning that they can't cool enough, they can't evaporate enough water to maintain their body temperature below lethal limits.
- 16:12So there's these acute events, these acute effects that are happening.
- 16:17And in Australia, there's been quite some big ones with cockatoos and the palm cockatoo.
- 16:25There was one population.
- 16:27I think they lost half the population in a single event.
- 16:33But most of the birds we don't see that are dying under these fence because they're in low densities, they're out in the desert, and we just see maybe changes in abundance through the different survey techniques we're using.
- 16:49But I think it's subtle.
- 16:50You know, we've lost 30% of the birds in North America since 1970.
- 16:55You know, there's all these different stressors, whether it's land use change or pesticides or...
- 17:02global change or whatever it might be.
- 17:05And heat is definitely one.
- 17:06Yeah.
- 17:07Well, God, cats, Jesus.
- 17:08Yeah.
- 17:10We talked about cats.
- 17:10We should maybe do a full episode about cats someday.
- 17:13If I really want to.
- 17:14Did you have Pete Mar on to talk about cats?
- 17:15No, but we've thought of it.
- 17:17I just know the cat episode will be extremely.
- 17:19Oh, it'll be contentious.
- 17:22Contentious.
- 17:22Not for me.
- 17:23I mean, I know how I feel.
- 17:25Yeah.
- 17:26You'll get some haters.
- 17:27You'll get some haters on there.
- 17:28When his book came out.
- 17:30I know.
- 17:30There were Amazon reviews were brutal.
- 17:33Brutal.
- 17:33I know.
- 17:34Yeah.
- 17:34Yeah.
- 17:35But cats do kill billions of birds.
- 17:39So that is indisputable.
- 17:40Yeah.
- 17:42Yeah, heat is another thing we need to be thinking about.
- 17:44And you're totally right.
- 17:45I mean, we've talked about bird flu on the podcast as well.
- 17:47And there you can, you know, if it's a colony that dies, you see it.
- 17:51Just like if it's a roosting group of budgies that all die, it's obvious you can count them.
- 17:56But for the most part...
- 17:58birds aren't existing in these large groups.
- 18:00And if they're dying as individuals out when it's 110 degrees, we're not going to see it.
- 18:05And we're going to see it reflected, like you said, in the longer term trends and population sizes and stuff, which as we've talked about many times are declining.
- 18:13So I guess if you live in an area that's experiencing heat waves and you want to do something, like if you want to try to help providing water is really the, the, the main thing you could do.
- 18:26Is that right?
- 18:27Yeah, I think providing water and shade, right?
- 18:29Shaded environments.
- 18:30I mean, these birds will, I mean, birds are very good at selecting the coolest spot in the environment to rest, right?
- 18:37So they're looking for microsites, we call them, that have the coolest microclimate.
- 18:42And so birds are already small, so they can be very selective in where they're sitting in the environment to try to reduce their evaporative costs, right?
- 18:51They can reduce evaporative loss by sitting in these cool shaded microsites for long periods of time.
- 18:58And so they do that.
- 18:59And then providing water.
- 19:00I mean, all these birds will use water when it's available.
- 19:05If you live in a big urban environment, like if you're in Phoenix or even Tucson, you've got a heat island effect where the asphalt is absorbing all this heat from the sun.
- 19:17It's re-radiating it.
- 19:18It elevates their temperatures of the environment by...
- 19:22you know, half a dozen degrees Celsius.
- 19:24And so you're really looking at a brutal environment.
- 19:28Go out and walk.
- 19:29We walk in the evening on the street.
- 19:32Oh, my God.
- 19:33And on a hot day, man, that re-radiation of energy from the asphalt
- 19:39is brutal, right?
- 19:40It is brutal.
- 19:41Yeah.
- 19:42Yeah.
- 19:42And on a previous episode, we talked with Olivia Sanderfoot about providing bird baths and things like that.
- 19:48And if you can, how to keep them clean and make sure that they're good and ready for your local bird population.
- 19:55One of the
- 19:55cutest examples, I think, of the seeking out the right microsite, at least in your area, down in the Southwest is the lovebirds in Phoenix that seek out like the AC coolant areas of the buildings, I'm pretty sure.
- 20:09Yeah.
- 20:12Yeah, that's a well-documented one.
- 20:15You know, one of the things we haven't talked about at all is humidity too.
- 20:19In human environments, prevent evaporation.
- 20:22Right, exactly.
- 20:23Yeah.
- 20:23You're not going to sweat much when it's 100% humidity.
- 20:26You can't sweat at all if it's 100% humidity, right?
- 20:29The sweat pours off you, it drips off you.
- 20:32Well, it's the same with birds.
- 20:33It's harder to evaporate water.
- 20:35And so
- 20:36hot humid environments are going to be particularly devastating for both humans and birds.
- 20:42I mean, there's areas in the Persian Gulf now that are going to be basically, you won't be able to go outside.
- 20:48They will be uninhabitable for humans during periods of the day because you can't cool enough to even get rid of the heat your body's producing.
- 20:56Okay, so many of our listeners are watching backyard birds like robins and sparrows and chickadees.
- 21:01They're not necessarily desert specialists.
- 21:03How well do the temperate species, so these ones not built for extreme heat, cope when a heat wave hits?
- 21:08Are they as adaptable, less efficient, or what's going on with them?
- 21:12So animals are adapted to their environments, right?
- 21:15And so animals that live in more temperate environments, cooler environments, don't have the capacity to deal with heat that desert species have.
- 21:23And so they reach lethal body temperatures more quickly.
- 21:27They can't tolerate the high heat loads.
- 21:29And so we're seeing, you know, die-offs at lower temperatures, right?
- 21:34And a place to look at this is, it's really anecdotal now.
- 21:39I don't think there's been any good studies, but I've talked to people up in the Arctic.
- 21:42The Arctic is warming four times faster than the temperate regions.
- 21:47Yeah.
- 21:47And so they've had anomalies where the air temperature's 20 or more degrees above what the average air temperature should be.
- 21:56You know, when it's 90 or 100 in Anchorage, Alaska, or 120 in British Columbia, right, there's nothing that's adapted to those kinds of air temperatures.
- 22:07And so, especially for breeding birds like up in the Arctic, maybe like waterfowl, they're.
- 22:15that are sitting in a feather-lined nest exposed to high solar heat loads, and all of a sudden the air temperature should be 50, but it's 90 or something, right?
- 22:25Or 55 or 60, and it's 90, and you've got this solar heat load.
- 22:29So I think for temperate species as well,
- 22:33They're less tolerant of high heat loads.
- 22:36And so they've got to deal with it, right?
- 22:41And I think that, again, that kind of chronic exposure is going to have real effects on both reproduction and survival.
- 22:49Yeah, totally.
- 22:50Just population sizes for sure.
- 22:52We've reached the part of the show we call That's BS or That's Bird Stuff, where we give our guests an opportunity to debunk a myth that ruffles their feathers.
- 22:59So Blair, what do you want to call BS on?
- 23:00Yeah.
- 23:01I mean, people seem to have this idea that birds are these very delicate little fluff balls of feathers.
- 23:09When you look at birds or if you work with birds or handle birds, you know that they're super tough and resilient as far as when you interact with them on a minute to minute basis.
- 23:20I mean, they may be canaries in the coal mine.
- 23:24or sensitivity to environmental perturbations, right?
- 23:27Whether it's pesticides or heat or some other thing because they have very high metabolisms.
- 23:36They, you know, use lots of energy and have high rates of respiration, all that.
- 23:40So they're really coupled with the environment.
- 23:42And so any, you know, any, say, insecticide in the food they're eating is going to accumulate very rapidly in their tissues because they have such...
- 23:52They bring in so much energy.
- 23:53But if you look at them on a day-to-day basis, I mean, they are super tough.
- 23:57Yeah, they're tough birds.
- 23:58Yeah.
- 23:59You know, you handle a hummingbird or something like that, and they just barely tolerate you.
- 24:04If they're a little bigger, they would attack you and try to kill you.
- 24:07Yeah, a hummingbird would be a dangerous beast if it was a big bird.
- 24:11Birds, by and large, have an attitude of where, you know, I can't be defeated.
- 24:16They're very resilient creatures, you know, and they're tough.
- 24:24Yeah.
- 24:24You know, they do incredible things.
- 24:26They're all Olympic athletes, right?
- 24:29If we look at human populations, there's one in a million that is an Olympic gold medal winner.
- 24:35Whereas in birds, they're all trained Olympic athletes that perform at the highest level.
- 24:40Yeah.
- 24:41And so I don't think we think of it that way because we think about our own performance and how miserable most of us are and pathetic.
- 24:49And yet birds are all Olympic athletes.
- 24:52I love that.
- 24:53Yeah.
- 24:53Yeah.
- 24:54That's it's BS that birds are fragile and delicate.
- 24:57They are these amazing creatures.
- 24:59Yeah.
- 25:00And I love that.
- 25:00Thanks so much for joining us today.
- 25:02It's been really awesome to chat with you about heat and though a bit depressing, super interesting to understand how birds are coping when we are experiencing these high heat events that we are more frequently now.
- 25:11So thanks again for joining the podcast.
- 25:13It's been my pleasure.
- 25:14It's been great.
- 25:15Lots of fun.
- 25:16Thank you.
- 25:20Birds are dinosaurs, and around here we like our snacks, so we end each episode with a dinosaur nugget.
- 25:24Today's nugget is, to start, birds run hot.
- 25:28Their body temperatures often sit in the 40s Celsius, temperatures that would easily kill you or me.
- 25:33We start to die around 107 or 108 Fahrenheit, roughly 42 Celsius.
- 25:38A bird can cruise right past that, and running hot is actually a feature, not a bug.
- 25:42The hotter a bird is compared to the air around it, the more easily it can dump heat the freeway passively with less expenditure of water.
- 25:49So when a heat wave pushes the air up toward a bird's own blazing body temperature, that cushion vanishes and staying cool suddenly starts to cost them.
- 25:56That's a wrap on this week's episode, Okay, but how do birds handle a heat wave?
- 26:00If you've ever been too hot, show us some love with a rating because we're sweating through this one in a studio with no AC in July.
- 26:06Catch you next time.
- 26:07Bye.
- 26:12Okay, But Birds is hosted by Scott Taylor with production and creative by Zach Carl.