Ornithologist Answers Bird Questions From Twitter

Evolutionary ecologist and ornithologist Sahas Barve answers the internet's burning questions about birds. How do messenger pigeons know where to go? Why are geese so loud? How do owls turn their heads so far? What's the smartest bird in existence? Sahas answers all these questions and much more!

Video Transcript

SAHAS BARVE: I'm Sahas Barve. I'm an evolutionary ecologist and ornithologist at the Smithsonian National Museum of Natural History. Today, I'm here to answer your questions from Twitter. This is Bird Support. [MUSIC PLAYING] This question is from @jehzoo. (READING) "How do messenger pigeons work? Do they have Google Maps or?" Some pigeons have very strong abilities to detect magnetic fields, but they also remember landmarks really well. A lot of homing pigeons also have what is called magnetite in their beaks and magneto receptors in their nervous system or brains. This magnetite basically helps them to orient in the right direction. So even if they can't see the sun, if it's really cloudy and windy and they can't orient themselves, they will know which way is north or east or west and south, based because of this really cool-- these magnetite particles in their beaks. The next question is from @WillJParker. (READING) "Jesus [BLEEP], why are these geese so loud? It's [BLEEP] midnight. Go to sleep, geese." Geese can be loud for multiple reasons. When they are getting ready to migrate, they honk a lot to sort of get their crew together. In the spring, they start pairing up, and they vocalize with each other to sort of [INAUDIBLE]. But they'll also then honk together to keep other pairs of geese away from their territory. They'll probably honk at you very loudly or even may like run up to you or charge you with their wings open if you are too close to their eggs or babies. A question from @imari. (READING) "Wait, how do birds have sex?" Most birds have sex by what is called cloacal kissing. Birds have a common orifice for pooping and peeing and basically having sex. And so first the males and females line up that orifice, and the male transfers the sperm into the female's cloaca. So that's true for most birds. But some male birds, like ostriches, have what pretty much looks like a penis. It's often called a cloacal protuberance. They insert that penis into the female's cloaca to transfer the sperm. Ducks have corkscrew-shaped penises. They go into the female's cloaca, which is also reverse corkscrew-shaped. Because there is so many forced matings in several duck species-- mallards being the most common example-- females actually also have blind alleys that don't lead up to their ovaries and eggs. And so if the female doesn't want to mate with a male that's sort of forcing himself on her, she can just get him to deposit the sperm in one of these blind alleys where his sperm will never be able to fertilize the eggs. The next question is from @br0k3nhalos. (READING) "How do owls turn their head so far around? Is their spine in the center of their neck?" Owls have this crazy ability to turn their heads almost up to 270 degrees, which is absolutely nuts. And here's a specimen of a northern pygmy owl that is showing you what it's doing. It's actually turning its head completely around, and that's something that you cannot do. There are two reasons why birds evolved the ability to do that. The first is that birds cannot move their eyes in their own sockets. So I can follow my finger without turning my head, and that's because I can move my eyes in my sockets. Birds can't do that. And so they have to move their head every time they want to follow another object. The other reason, when I turn my head all the way to the back, after a bit of time, I'm going to cut off the blood supply to my brain. It's not going to be very nice in a few seconds because I'll probably pass out if I keep doing that. But owls have evolved this really cool blood supply network that actually compensates. Other blood vessels take over and keep supplying blood to the bird's brain. This bird is also really cool because it has these markings that look like eyes at the back of its head. A lot of owls around the world have those markings, and they are also supposed to be an antipredatory strategy. Constantly saying, hey, I'm looking at you, even if they're not. By @FunkyDiabetic1, (READING) "How do birds all know where to go at the exact same time?" The simple answer is they're just watching their neighbors. These big murmurations of starlings-- that you may have seen videos of-- do these really cool formations in the air. Well, we don't know exactly why they do that. But they are doing what the next few birds around them are doing. So you will see a few birds turn, and that sort of wave goes through the whole flock. They are not that coordinated as a whole flock of 1,000 birds. But they coordinate with their immediate neighbors that are flying around them. When geese or storks fly in a V, there is some thermodynamic advantage. And the bird in the front is working the hardest. And often the bird in the front will give up and go back in line, and another bird will take its place. Birds sort of coordinate who is doing all the work when they're flying, too. Make everyone's energy use more efficient. Next up, from @locallystupid, (READING) "How do birds not get cold? I feel like they need a jacket." So most birds have a feather that is part down, these fuzzy non-interlocking barbs that basically catch air close to the bird's body, very similar to mammal fur. Penguins live in really cold environments, and they have extremely dense feathers. There are other birds that live in very cold environments as well. In Northern Canada, there are chickadees that live in like -20 degrees outside, and the chickadee is like the same weight as a couple of teaspoons of sugar. The feathers in your down jackets come from geese and ducks. And so we have actually used their feathers to keep us warm now. Next up is a question from @tonysabad, "say-bad"? (READING) "What's the smartest bird? I bet you it's none of them." New Caledonia crows are supposedly wicked smart because they can design their own tools. And you can give it a stick, and it will make it into a tool that it will use then to get to a treat that you set up for it. Also, birds are really smart because they can fly from Alaska to New Zealand and find the exact same spot that they found last year. Try going anywhere without Google Maps yourself, let alone across continents. @CbdElizabeth, (READING) "Do all birds lay unfertilized eggs the way chickens do? Do wild songbirds lay empty eggs?" Most birds don't want to lay unfertilized eggs because unfertilized eggs is a lot of energy and resources. Some birds lay eggs that are as much as 20% of the bird's body. There are birds that lay unfertilized eggs but as part of a bigger clutch of eggs of fertilized eggs. Chickens that lay unfertilized eggs have been manipulated hormonally generally to produce eggs that are unfertilized. Do wild birds-- wild songbirds lay empty eggs? If you mean something like a ping-pong ball, then they don't because the egg shell is actually a covering that goes onto an embryo. So inside of the egg forms first, and the egg shell is sort of like sprayed on around it and then hardens. They can't just form the outside without the inside, so they don't lay empty eggs. This question is from @DudasClancy. (READING) "Do birds eyes dry out as they soar through the skies?" Birds have this third eyelash, called the nictitating membrane. It's a transparent membrane so birds can actually use it while they're flying. If you watch a bird up close, you can actually watch them use their nictitating membrane to wink their eye close and shut. But the nictitating membrane itself is completely transparent, and so the bird can still keep seeing when it's doing that. Next question is by @DekelDw. (READING) "Do all birds build nests?" Most birds build nests. But several different families of birds evolved what is called brood parasitism, where females lay eggs in another individual's nest, and that can be another individual of the same species or another individual of a completely different species. Cuckoos, for example, go and lay their eggs in the nests of other birds. Those eggs generally hatch out earlier and push out all the other babies. And then the parents end up raising just the cuckoo chick. A quick anecdote about that is that cuckoos know that the host birds can count. When they go to lay their eggs, if they find four eggs in the nest, they will lay one egg and then take out one of the host eggs to make sure that the host doesn't find out that there are suddenly five eggs when they only laid four. @mistress_time, (READING) "What the [BLEEP] are emus? Why do they make that sound? They're literally dinosaurs wtf. Why the hell is there a bird that's taller than me? This isn't fair." The emu is not even the biggest bird in the world. So the ostrich is bigger than the emu. They are pretty big. Well, I'm glad you brought up dinosaurs because birds are, in fact, more closely related to dinosaurs than any other animal that ever lived on Earth. Why are they so big? Well, there's a bunch of birds, ostriches, emus, and cassowaries. These three birds are really, really big. They can be as tall as people or even bigger. They are just an ancient lineage of birds. Now that you know that birds are actually dinosaurs, they're actually pretty small, right? From @humusbeings or "hoomus" beings, (READING) "What's the loudest bird for its size? Two New Holland honeyeaters can make quite a racket." Loudest recorded bird is a white bellbird. [LOUD BIRD CALL] Most of their sounds they make are above the frequencies that we can actually hear. But they can be extremely loud. Those birds can be louder than some planes even. They often use that to attract mates. From @martymush, (READING) "Do birds ever know where they're actually going when they go south? Or do they keep flying until it's warm? I feel like they aren't just like we're going to Florida. Pack it up." Well, birds do know where they're going, and they'll often use the earth's magnetism, the stars, and several landscape features to direct where they're going. Birds have the ability to go across continents and find the same patch of forest that they spent last winter in. GPS trackers have shown that some birds, like the bar-tailed godwit, fly nonstop for 12,000 miles from Alaska to New Zealand and find the exact same patch of wetland that they used the previous winter. @eelaizha, (READING) "Are there any birds with teeth?" That's one of the weird mysteries of bird evolution. Before the dinosaurs went extinct, there were a lot of birds with teeth. And then after that, there are no birds with teeth. There is no real reason why there are no birds with teeth today. None of them, for some reason, survived the same apocalypse that wiped out the dinosaurs. From @rainelew3, (READING) "How do birds fly in the rain? Explain it to me now." Birds fly in the rain just like they fly in any other weather. Bird feathers have highly water-resistant parts called the pennaceous part, which stops the water from actually going in and soaking the rest of the bird. When they take a bath, they can dunk themselves in water. Many ducks, you may have seen on the water, and they emerge without getting wet. It's because they are like wearing a rain shell the whole time. @imReactss, (READING) "Do birds ever fly just for fun or are they always on some sort of a mission?" Just like you and me, many birds play. Crows and ravens will often play, and you will see them doing these really cool tumbling dives through the air. Crows and ravens are a good example. They will fly to have a game with their flock mates, and they will fly around just when it's really windy. Or I don't know, just for the fun of it. @ziahxt, (READING) "Bro, how do owls not produce sound while flying?" That's a great question. Owls have really cool adaptations to reduce the amount of sound they make. Owls are generally nocturnal. And most animals that are nocturnal have a really good sense of hearing. Owls have evolved this way to sort of cancel the amount of noise that they're making when they're flying from the flapping by the cool feathers they have. So the owl feathers, the ends of the barbs, have like combs or little brushes that basically break up the air in a way that it doesn't produce a sound when it's flying. Not all owls have that, but most owls have that. From @mkangwenyi, (READING) "Is there a Shazam for bird call?" You can download an app called Merlin and then record a bird call. And then Merlin will help you ID it and tell you what bird it is. But you can generally filter down from all the birds that are in your field guide to just a few species, based on the size of the bird, the habitat you're seeing, and where you are seeing the bird on Earth. That's something that you learn to do from when you start birding. Next question is from @AuthorRKK, (READING) "How do birds learn how to use tools? I'm curious." Several birds show tool use. Egyptian vultures will use giant rocks to smash open ostrich eggs. Darwin's finches on the Galapagos Islands will use little sticks as spears to fish out caterpillars and beetle larvae that are hiding underneath the bark of plants. We don't know how birds learn to use tools. They definitely watch others as they make tools. We know this from New Caledonian crows, and we know this from ravens and from keas that they are very, very good social learners. You and I learn new tricks from watching someone else do it. Birds, they watch another bird. Study what the other bird is doing. Especially if the tool the other bird is using ends up in them getting a treat, then they'll definitely be very, very careful about learning that and then go try it themselves. By @Ubermoogle, (READING) "Curious amateur birding question, is beak color variable within species, or is it a defining character?" Beak color changes both within species and within an individual also. European starlings will actually change the color of their beak in the summer than in the winter. And color of the beak is also driven by some of the same compounds that drive the color of feathers. The variation in bird beak color within the species is often used to identify different populations from each other. @SUEtheTrex, (READING) "Ornithology question: do birds in tropical zones migrate like they do in temperate climates? How can you tell what species will be where throughout the year?" Many birds will often migrate just to find food. So a lot of birds will fly between areas with high rainfall to areas with low rainfall. This includes a lot of birds in Australia and a lot of birds in Africa that follow the rain clouds across the continent rain generally produces a new flush of vegetation, which produces a new flush of insects that these birds feed on. Parrots will follow fruiting cycles of different species of trees, just because they know that their favorite fruit will be fruiting in that area. (READING) "How can you tell what species will be where throughout the year?" Your bird guide will generally tell you whether a bird is a year-round resident or is found only in the winter or in the summer. That's something for you to find out as well. You can go birding and make a list of birds that you see. At the end of one entire calendar year of birding, you will know what birds you see throughout the year. This question comes from @drdelarocker. (READING) "Ornithology question: do birds breed interspecies? My wife and I were talking about dogs and mutts, and we realized that we don't know if there's a bird equivalent. Can an albatross mate with a wren or something like that?" Two breeds of dogs, even a Great Dane breeding with a chihuahua, is the same species breeding with each other. An albatross and a wren, probably as distantly related to each other as a human and a goat are. There are many species of birds that do hybridize with other species, but those are very closely related to each other. A good example maybe a wolf and a coyote breeding with each other. That happens pretty regularly in nature. Just because they're birds doesn't mean that they can mate with each other, although closely-related species will often hybridize with each other to produce offspring. I enjoyed answering your questions today. And I hope you learned a little more about birds and appreciate birds a little more. Happy birding. [MUSIC PLAYING]