For halloween, take a bat walk… image by Simon Howden

Halloween is coming in a couple of weeks and the Moon is waxing to full by next Sunday. This a great time to get out in the evening, in the cool fall air, and look for those animals that come out in the night. One of my favorite night time animals is the much maligned bat.

Bats start coming out in the evening hours just after sunset, in the dusk hours, seeking the insects that come out at that time of day. A small bat can consume between 600 to 1200 mosquitoes an hour. Yes, that’s an hour. They hunt using a combination of sight and echo location, bouncing sound signals off of their insect prey, to help find them. They can even tell which insects are their favorites by the sounds that bounce off of the insect. The Natural History Museum in London has an awesome animation that shows how this works. Contrary to popular myth, bats are not blind, they actually have better night vision sight than the best night vision glasses.

There are 4 families of bats in the US and 45 species. The most common of the species in N. America are the Big Brown Bat and the Little Brown Bat. In the south you’ll find the Mexican Free Tailed Bat. These are the bats that fly out of Carlsbad caverns each evening from spring to fall. While most bats hibernate or go into a winter torpor when temperatures drop, the Mexican Freetail Bat will migrate south for the winter. Some bats roost in large colonies in caves while others will seek any crack or crevice for their roosts. You cal learn more about bats in your state here

Bats are important to the environment. They are an important indicator species of the health of the environment because they are sensitive to pesticides and habitat loss. Bats that eat insects help keep insect populations in check. Fruit bats spread seeds of the fruit they eat around helping plants to colonize new areas. Other bats eat nectar and are important pollinators. Some plants depend on bats for pollination and when the bat species disappears, the plant can no longer reproduce.

There are many myths about bats but most of them are not true. Some people associate bats with Vampires but most bats are either insect or fruit eaters. There are three species of bats that live in the central and south American tropics of the western hemisphere that do drink blood. They will bite a small hole in the skin of an animal and lick the blood as it drips down. Even this, slightly creepy bat has helped humans. The saliva of the bat has chemicals that keep the blood from coagulating. By studying the bat, scientist were able to develop medicines that help heart patients.

Many people are afraid of getting rabies from bats but this is very unlikely. According to Bat Conservation International only 1 in 200 bats has rabies (that is 1/2 of 1%) and these animals are usually too sick to fly. If you see a bat that allows you to approach it, this is not a good sign. Most bats will fly away from you if you attempt to get near them. Wild animals that will let you near need to be left alone because it is unnatural for them to allow this. Call an wildlife rehabilitator for advice.

In closing, the best place to look for bats is in open areas, near water, there are a lot of insects there. Watch for bats to come out around dusk, just when the sky is becoming dark. Look against the open sky for dark fluttery shadows. Because bats are looking for flying insects, they fly in swoops and dives and unlike birds, their flight patterns are random. If you are in a quiet area you can listen for  the clicks and chirps they use for echolocation. Younger ears are better at hearing them. You can listen to the Big Brown Bat by clicking the link. You can listen to more sound files here.

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