Seven things you probably didn't know about bats

There's more to know than bats flying at night and living in caves

Since 2024, I’ve been blogging for Bat Conservation International (BCI), a tremendous conservation organization that works to save bats and their habitats throughout the world. In that time, I’ve learned lots about bats, their diets, life cycles, and habitats. I’ve learned about their ecology, how insectivorous bats control agricultural pests and how fructiferous bats serve as pollinators and seed dispersers.

Blogging for BCI has been a real joy. Here are just seven fascinating things I’ve learned about bats.

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1. Scientists know almost nothing about bats’ evolution.

If Darwin had studied bats, we may not have his theory of evolution. That’s because in the fossil record bats appear suddenly during the early Eocene in the northern stretches of the supercontinent Pangaea, almost as if they were plopped upon the earth by a bat creator. All the evolutionary links are missing. There is no equivalent of Homo Erectus or other human evolutionary links. It’s almost like some evolutionary magic trick. For hundreds of millions of years there is no evidence of bats, no evidence of their ancestors; then poof! Suddenly there are bats!

Even though they have been around for about 50 to 52 million years, in that amount of time, there seems to be very little evolution. The earliest bat fossils reveal creatures who very much resemble present-day bats, with fully functioning wings and the same anatomical traits as modern bats.

2. Bats are related to whales.

OK all the evolutionary links are missing, but because of shared evolutionary traits, scientists are able to group bats into the subclass of placental mammals; that is, mammals whose birth process includes placentas, just like cows, cats, humans, and (wait for it) whales.

Both bats and whales share a common ancestor as demonstrated by their placental birth, and both have the ability to echolocate; i.e., “see” their surroundings by emitting sounds and listening to those sounds reflected back to them. However, both animals evolved echolocation methods through different evolutionary mechanisms.

3. Bats fly at night because of birds.

By the time bats came along, birds had been around for at least 100 million years, and the birds had monopolized the skies during daytime. To avoid competition with insect-eating birds, such as swifts and swallows, bats evolved to fly after the sun went down.

4. There are LOTS of bat species.

Few, if any, creatures have taken to the night sky as bats have done. And when they did so, they were able to take advantage of numerous food sources. Some bats evolved to eat insects, others evolved to eat fruit or nectar from flowers. Bats explored new habitats, too. C’mon, who else lives in a cave?

Because these evolutionary opportunities opened up, bats diverged in what scientists describe as an evolutionary “big bang” unique among mammals. Bats evolved into over 1,400 separate species, comprising 20 percent of all mammal species.

5. A few bats eat fish.

Most bats eat insects; some subsist on fruit or nectar; and a few species are vampire bats, drinking blood from hosts. In addition, there are at least two species of bats that fish. In the Sea of Cortez, the fish-eating myotis (Myotis vivesi) flies low and slow, combing the surface of the water with their large feet to catch fish and other aquatic prey.

The greater bulldog bat (Noctilio leporinus) lives throughout the Caribbean, as well as Mexico and Central and South America. This bat will circle above the surface of a body of water, using echolocation to detect the ripples made by fish below. These bats will also rake across water’s surface facing their feet forward, grabbing fish in their paths.

6. Some bats migrate like birds and other animals.

People usually assume bats live in caves and that’s pretty much it. But a lot of bats roost in trees or other outdoor places. In the United States we usually don’t notice these bats as they are well camouflaged.

Many of these tree-dwelling bats move between summer and winter habitats. They will migrate as much for food availability as to keep warm. Because they are small-bodied, bats lose heat more readily than larger animals, so living in a cold environment is extra taxing. Hoary bats and Mexican free-tailed bats migrate between the U.S. and Mexico according to the seasons.

7. A lot of bats hibernate.

Many bats that don’t migrate will hibernate for a portion of the year. Like other animals, some bats go into hibernation during cold spells and long periods when food is scarce. Typically, during hibernation, a bat’s heart rate drops from around 200 to 300 beats per minute to only ten beats per minute. Breathing rates also drop greatly as well. Additionally, bats can allow their body temperature to fall, in some cases to just above freezing, which slows their metabolism. All this metabolic slowing can reduce the animal’s energy output by 98 percent.

Hibernation usually lasts weeks or months. Bats can also enter a short term hibernation, sometimes lasting just hours, called torpor. Torpor is also brought on by environmental factors such as temperature and food availability.

Do you have a little known fact about bats? Have a recent observation of bats? Please share by clicking the “Leave a comment” button below.

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