Birds are the animals most associated with flight. Because of this, any flying creatures—fictional or real—are often given traits like birds. Building nests, singing songs, pecking holes, and so on.
Although birds are the most numerous of all flying vertebrates in terms of sheer number of species, they are only one group of the numerous creatures that take to the skies. Insects and bats are generally excluded from the All Flyers Are Birds trope, since they still live with us and we know their behavior like it's nothing, but prehistoric and fantasy creatures are still at risk. If you come across anything non-sapient with wings, expect it to perch on a tree at some point or another, or worse yet, tweet in a bird-like fashion. This may be acceptable in fantasy animals because they are, of course, original creations/species and you can do whatever the hell you want with them, but it's probably not as good an idea to apply this trope to species that really existed (or even worse, species that still do.)
This is a subtrope of All Animals Are Domesticated, and is essentially the airborne version of All Animals Are Dogs. Can also overlap with Fantastic Fauna Counterpart, if non-avian flyers are treated as the setting's equivalent of birds. For specific examples related to prehistoric life, see Ptero Soarer and Raptor Attack (for the case of Archaeopteryx and other early birds). For examples of birds themselves being treated badly, see Artistic License Ornithology.
- Prehistoric creatures in particular are guilty of this, especially pterosaurs. It's often the case that they stand on two legs, perch in trees, and construct bird-like nests. While it's debatable whether pterosaurs could climb trees, we do know that they were actually quadrupedal and nested on the ground. In a similar manner, Archaeopteryx and other early bird relatives are depicted as being able to perch on trees. In reality they were more similar to non-avian deinonychosaurs, and were most likely ground-dwellers which could only glide for limited periods of time.
- On the mythology side of things, wyverns (a type of dragon or dragon-like creature, depending on the work in question) are often depicted as having birdlike proportions and mannerisms, due to their decidedly avian body plan (two legs and two large wings). For example, you can often expect them to fill the role of Kidnapping Bird of Prey if no other mythological winged monsters are available.
- Griffons tend to be depicted more like birds than lions, despite being half and half. This is probably justified because their heads are mostly birdlike (which would imply a bird's brain), but depicting an animal with the hindquarters of a placental mammal laying eggs is fairly confusingnote .
- Cloudy with a Chance of Meatballs: The ratbirds tend to behave like actual birds, though with some rat-like tendencies, despite being simply rats with wings.
- In How to Train Your Dragon, the Deadly Nadder is the most bird-like of all dragons. It walks on two legs in a rather bird-like or dinosaur-like manner, preens its scales, makes bird-like squawks and warbles on occasion, and turns its head to the side when it looks at you, in a rather similar fashion to the songbirds who hunt worms in your everyday garden. Averted by other dragons, though. Toothless in particular incorporates behaviors of big cats and horses.
- In The Flintstones in Viva Rock Vegas, a pterodactyl bores through wood like a woodpecker.
- Indiana Jones and the Temple of Doom: Done in-universe. Willie Scott, an extremely naïve Midwesterner who has apparently never been anywhere else other than Shanghai (where she performs her nightclub act), is riding an elephant through the Indian forest with Indiana and Short Round. She points out some "big birds" flying overhead — and Indy informs her that those aren't "big birds", but giant bats.
- Jurassic Park:
- Jurassic Park III: The Pteranodon nest in a very bird-like way, although the current paleontological evidence certainly says otherwise.
- Jurassic World: Played with. The Pteranodon have grasping talons and jump to launch rather than vaulting with their wings. They also dive like gannets, but this quality is actually accurate to what real Pteranodons were capable of (indeed, it's believed to have been their main hunting method).
- One Million Years B.C. has pterosaurs with eagle-like talons. Again, the Pteranodon also has a bird-like nest, complete with oversized Pteranodon babies.
- Rodan: In many of his appearances, Rodan exhibits several examples. He perches like a bird, builds a nest, lays outsized eggs, and grasps things (such as dolphins) in his talons. Considering Rodan is a fictional movie monster, the filmmakers weren't likely going for realism. Early concept art of Rodan went the extra mile and gave him feathers◊. Granted, at least some of these images also bear some resemblance to early artistic renditions of Archaeopteryx so it's possible that Rodan wasn't always intended to be a pterosaur.
- Rodan's incarnation in Godzilla: King of the Monsters (2019) makes him decidedly more avian in mannerisms and behavior, with a much more vulture-like head, grasping talons and a bipedal stance and launch. Once again, feathers were considered in concept art, but ultimately were scrapped.
- One of the creatures in Evolution that terrorizes a mall was a scaly, lizardlike creature with bat-like wings, a total of six limbs like a traditional European dragon, and gave birth by vomitting out young. The film's protagonists, oddly, refer to the creature as a "bird".
- Animorphs: Ax describes the six-winged kafit as one of three "bird" species on the Andalite homeworld.
- The Andy Griffith Show: Barney believes bats lay eggs.
- Primeval: The Anurognathus perch in the trees like birds do.
- Walking with Dinosaurs: Anurognathus appear as a symbiote of Diplodocus, intentionally following it and feeding on the insects living on its skin in the manner of modern birds like oxpeckers and cattle egrets. There is no basis for this, and in fact Diplodocus and Anurognathus lived in different continents (although a close relative of Anurognathus, Mesadactylus, did live in the same place as Diplodocus). Research done since the release of Walking With Dinosaurs suggests that Anurognathus was nocturnal and caught insects while flying. Interestingly, that's still an example of this trope, as the same behavior is exhibited by modern birds like the nightjar.
- The Bible says bats are birds in Leviticus 11:13-19:
"These are the birds you are to regard as unclean and not eat because they are unclean: the eagle, the vulture, the black vulture, 14 the red kite, any kind of black kite, 15 any kind of raven, 16 the horned owl, the screech owl, the gull, any kind of hawk, 17 the little owl, the cormorant, the great owl, 18 the white owl, the desert owl, the osprey, 19 the stork, any kind of heron, the hoopoe and the bat."
- Locusts are also classified as "fowl". The Hebrew translated word pretty much means "flying things" rather than specifically birds, but the King James Translation didn't get the memo.
- The Eternal Cylinder has the Onkifurt: a bizarre-looking Living Gasbag Starfish Alien with a gaseous sac, a vaguely pig-like snout and two tentacles. Despite looking nothing at all like a bird, it seems to behave a lot like one, brooding its eggs in a nest, hunting prey by dropping on them from above, and displaying sexual dimorphism like many birds whereas males are more colorful than females.
- Pokémon: A lot of Flying-type Pokémon that have a bird-like body shape behave in a sort of avian fashion. Aerodactyl, for example, is often seen standing on two legs and carrying things in its talons like a bird of prey. A few bird Pokemon invert this trope, though, such as the flightless Doduo and Dodrio.
- Even the Zubat family can learn moves named for or associated with birds, such as Brave Bird and Sky Attack (in Japanese: "Godbird"). Woobat, however, averts this.
- The animation for Wing Attack shows feathers flying after the opponent is struck, even though Pokemon that can learn this attack include those that are based on bats, pterosaurs, dragons, dragonflies, mantises, manta rays...
- The logic behind Flying-types being strong against Bug-types seems to be "birds eat bugs". That said, this can still be justified with creatures like Zubat, Aerodactyl and Scyther as there are indeed species of bats, pterosaurs and flying insects that eat bugs as well (though a pterosaur as large as Aerodactyl would probably prefer more substantial prey). Less justified when you consider that the aforementioned dragons and manta rays share this advantage.
- Inverted with Lugia who is supposed to be some sort of bird-monster, but looks more like a dragon and doesn't act very bird-like at all (It sleeps in a cave at the bottom of the ocean rather than in a nest). Even the games point this out.
- It appears that the Flying type was originally going to be called Bird, and all bird-based Pokemon in Generation 1 were classified in it, whether they could fly or not. The reason Psyduck isn't is because it isn't based on a duck, but on a platypus.
- Altaria is a inversion of this trope. It's a bird, but it's a Dragon type. When it mega evolves, it becomes Dragon/Fairy, while still remaining a bird. All that changes is it get more clouds and its tail grows longer.
- Spyro 2: Ripto's Rage! has "pterodactyls" that look like birds, grasp like birds, and make hawk-like noises.
- Star Control II: The Yehat have particularly bird-like mannerisms, and call themselves birds, despite clearly resembling either dragons or pterosaurs of some sort. Despite this, they are not earth animals at all, and are aliens. Their original dialog, before the 3DO version, and later the PC port The Ur-Quan Masters added voice, even had them squawking and making other various bird noises. This was replaced with a Scottish accent in the voiced editions.
- Tales of Symphonia: Occurs only in writing, where, presumably for simplicity, creatures such as bats are classified as birds in the bestiary.
- Mortasheen actually inverts this trope. Most of the birdlike monsters there don't behave like real birds at all, and the one monster that is claimed to actually make a bird-like song doesn't even look like a bird at all!
- Hamster's Paradise averts this with the ratbats, the flying descendants of hamsters that fill various avian niches. Aside from their ability to fly they have nothing in common with birds and are anatomically and behaviorally more alike to bats and pterosaurs. Conversely they expand into ecological niches never taken by either bats or pterosaurs as flightless penguin-like swimmers, terror-bird like predators and ratites, so its more like "all former flyers are bird". However, in the original concepts, a much later clade of hamsters called the ratbirds plays this trope straight: they are bipeds with perching feet, have slotted wings resembling "feathers", have rodent incisors modified into "beaks", and lay a mammalian equivalent of an egg.
- Avatar: The Last Airbender: A fair few of the Mix-and-Match Critters are partially based on birds, and so have bird-like mannerisms. The ostrich-horses are an exception, though, because their behavior is a lot more equine.
- The Flying Squirrel features a flying squirrel. While it doesn't flap its arms in imitation of a bird, its flight movements are birdlike in every other way. It can move up and down and a couple of times it even hovers.
- I'm A Dinosaur has feathered, bipedal pterosaurs that live in trees.
- Dino Ranch's baby Pteranodon Pteddy acts as the farm's rooster, crowing at sunrise to wake everyone up. He even walks around on two legs like a bird rather than on all fours like real pterosaurs did.
- Early classification systems classified bats and bees as birds. However, this was less due to poor scientific understanding and more because people in ancient times used "bird" as a generic term for any winged creature. The modern usage of bird to refer to feathered, beaked, egg-laying, present-day dinosaurs came about with the rise of proper scientific study. The term "fish" has evolved in a similar manner, having been formerly used to refer to any water-dwelling creature from whales and crabs to octopuses and turtles.
- Many pterosaurs in real life did in fact fill specific niches similar to those of modern birds. The famous Pteranodon fed like a pelican, diving into the water and snatching fish up in its beak. Rhamphorhynchus fed much like a seagull. Pterodactylus was a wader/prober like a shorebird. Pterodaustro filter fed like a flamingo. The giant Quetzalcoatlus was a massive marabou stork in behavior, picking up small animals with its long beak while walking around and swallowing them whole. Harpactognathus hunted like an eagle. Istiodactylus scavenged like a vulture. Anurognathus and its ilk were nocturnal aerial insectivores like nightjars (and bats). Tapejara and Tupandactylus may have been omnivorous fruit-eaters like hornbills. Indeed, some scientists believe that birds developed the diversity they have now to fill the niches left behind by pterosaurs after they went extinct (though this is somewhat controversial).
- If you want to have some fun with cladistics and define "bird" as everything that is closer related to modern birds than to modern crocodiles (the most liberal possible definition; this clade is currently called Avemetatarsalia or Pan-Aves, although Ornithosuchia was used prior to 1990), then that would indeed include the pterosaurs. But it would also include all dinosaurs, of which most note definitely could not fly.