Bats are one of the most important animals to share our space on this planet. They are also some of the most misunderstood. Throughout recorded history bats have been associated with evil, witchcraft, and generally scary things—the legend of Dracula, Halloween, and in recent times, beliefs that bats will attack people, get caught in their hair, or that “they all carry rabies.” It is time to set the record straight.
In reality, all bats are an important part of their ecosystems. Some bats feed on nectar and fruit and pollinate the plants that provide them. A few of these bats (the so-called vampire bats) are fairly large and feed also on small amounts of blood from animals. They do not bite people on the neck. And they only live in tropical areas, not in the Central Highlands of Arizona.
Bat box in the Highlands Center meadow
There are about fifty species of bats native to the United States. Nearly all are insectivores. Bats can eat a prodigious number of insects. Arizona is home to only six species: the big brown bat, the little brown bat, the red bat, the hoary bat, the Brazilian free-tailed bat, and the silver-haired bat. These bats are all very small, ranging in size from two to four and one-half inches in length. Bats are the main predators of night-flying insects, each one eating nearly its entire body weight each night. And a nursing mother bat has to eat even more in order to provide milk for her pups.
Bats are extremely interesting creatures. They are the only mammal capable of true flight. (Flying squirrels don’t count. They can only glide from one perch to another or to the ground). Although bats can see fairly well, they use a system of echolocation to locate their prey. The bats make an extremely high-pitched noise, which bounces off an insect and back to the bat’s ears, enabling them to find their meal.
Most bats use their interfemoral membrane (connecting the back legs to the tail) or wing membranes to actually catch the insects, which they then pick up with their mouths. Only the Brazilian free-tailed bat actually catches its prey with its mouth, because its tail is not attached to the membrane.
Bats migrate to warmer climates in the fall and hibernate during the winter. Most bats live in colonies and often roost closely together for warmth. They like dark places like caves or attics (they sleep during the day, after all) where the temperature is relatively constant. Areas, where large numbers of bats hibernate together, are called hibernacula. Female bats have one or two pups in the spring or early summer, after waking from their winter sleep. The babies cling to their mothers’ fur during sleep periods. When females are foraging, babies are left in the roost, but checked on frequently. Mother bats nurse their pups until they are able to fly.
Next month: more information about bats. Are they in danger?
Contributed by HCNH Naturalist Sandy Stoecker