Bats are mammals of the order Chiroptera, and are actually not closely related to birds at all.
However, it is a common misconception that bats are a type of bird, so what’s causing the confusion? Why do some people think that bats are birds, and what characteristics make them definitively mammals?
Why do people think bats are birds?
Bats are most often mistaken for birds because they can fly, which is a pretty unusual talent for mammals. In fact, bats are the world’s only flying mammal and even their wings are pretty unique. The word ‘Chiroptera’ is derived from Ancient Greek and translates literally as ‘hand wing.’ This is because, unlike birds, the wings of bats are adapted from their hands.
Each supporting bone in the wing of a bat is actually an elongated finger bone, and the webs between them are made from flaps of membranous skin. This is very different to birds, whose wings are formed from the whole arm. Bird wings are also rigid and feathery, and the whole wing must be flapped to allow the bird to fly.
Bat wings, on the other hand, are highly flexible.
This allows them to change direction quickly while flying and enables them to capture insects in mid-flight.
Why are bats classed as mammals?
Bats and birds are both able to fly, and both share a diet of fruits, nectar, and insects. But this is where the similarities end, and there are several big differences between bats and birds.
Do bats have feathers or fur?
Unlike birds, which have feathers, bats are furry. Bats have fur on their bodies, and sometimes on their heads, but their wings are bald.
Do bats lay eggs or give birth?
Birds lay eggs, whereas bats give birth to live young. The pregnancy of bats lasts for 6 to 9 weeks, depending on the species, after which they give birth to a single baby (called a pup). Bats typically have one pup per year.
Do bats feed their babies milk or bugs?
Like all mammals, bats lactate and feed their pups on milk. Birds do not produce milk, and instead feed their chicks on partially digested, regurgitated food. When the chicks get a little older, they may also be fed whole insects and worms.
Do birds have beaks or teeth?
Birds have beaks, but bats do not. Instead, bats have jaw bones and a set of sharp teeth.
Similarities between bats and birds
Bats are mammals and are, therefore, very different from birds. However, there are some similarities between the two.
Bats and birds both fly
The biggest similarity between bats and birds is that they can both fly. Bats are the only mammals on Earth to have evolved this skill, which is why they used to be thought of as featherless birds
Bats and birds eat a similar diet
Bats and birds are both insectivores, meaning they eat insects. In fact, they are even thought to eat the same types of insects, namely flies and mosquitoes. Both bats and birds may also eat fruits and nectar.
Bats and birds both spread diseases
Both bats and birds can spread diseases in their droppings. Histoplasmosis is caused by a type of fungus found in the poop and guano of pigeons, starlings and bats and, though rare, can cause serious symptoms. Bats are also known to transmit rabies, though birds cannot contract or spread this disease.
Are bats dangerous to humans?
Globally, bats have a bad reputation.
This is partly due to their role in popular horror fiction (like Dracula), partly because of their reputation as rabies-carriers, and partly due to myths about them getting tangled in long hair.
The truth is that most bats are completely harmless, and are actually shy creatures that will usually avoid contact with humans. Yes; vampire bats exist, and yes; they are the only known species of bat that feeds entirely on blood. However, their blood of choice is bovine, and attacks on humans are exceedingly rare.
Rabies is a more valid concern, as bats are known carriers of the disease. In fact, bats are known vectors for dozens of viruses, some of which (like Ebola) can have devastating effects on human health. Fortunately, only a very low percentage of bats actually have rabies, so your chances of contracting the disease from them are negligeable.
Though it’s not always possible to tell if a bat has rabies, you can avoid contracting the illness from them by never attempting to handle them (or any other wild animal).
Warning signs for rabies in bats include:
- Daytime activity
- Obvious disorientation or inability to fly
- Unusual resting activity (e.g., in your house or backyard)
- Willingness to be approached
Bats and birds are both capable of flight, and both have a similar diet. However, this is where the similarities end, as bats are actually mammals. This means that, unlike birds (which lay eggs), bats give birth to live young, which they feed on milk. They also have fur instead of feathers, and a jawbone with teeth in place of a beak.
The wings of bats are also very different from those of birds and are, in fact, elongated hands with membranous skin stretched between the fingers. These skin-wings are highly flexible (unlike the rigid, arm-like structure of the bird’s wing), allowing them to change direction very quickly while flying.