Rabid bats in our belfry
July 3, 2008 · Updated 3:11 PM
Although Halloween is over, the night skies are still being patrolled by dark, winged creatures that flutter, largely unnoticed by people, in search of a meal.
About 15 species of bats inhabit the Puget Sound region and chances are they live in your neighborhood. The mysterious mammals have long been associated with the haunted season and Dracula legends, but the truth is they do much more good than bad in the world.
Yet the main concern with bats is rabies. Two bats that tested positive for the deadly virus were collected from Island County homes in the last three months. One was found in a Camano Island house Aug. 27.
Last week, a Whidbey Island woman found a bat in her bathroom. Lori Clark at the Island County Health Department said the bat apparently flew into the house when the resident took the windows off to clean. It was in the home overnight until it was discovered in the morning.
Clark said both bats were brought to the Health Department, where they were sent out for testing. They both came back positive for rabies. Since the families couldnt rule out contact with the bats, they underwent post-exposure anti-rabies treatment. The painful series of five shots can cost up to $1,000 per person.
Its not that it is common for bats to be rabid. According to Bats Northwest, studies show that less than one-tenth of one percent of wild bats are rabid. But Clark said about 10 percent of bats that are caught and tested turn out to have rabies.
Bats dominated rabies reports
Sarah Schmidt, a Coupeville resident who got her Masters degree studying bats in Arizona, explained that rabies is as prevalent in other wild mammals coyotes, opossums, raccoons as it is in bats. Yet in Washington state, most of the cases of rabies in animals occurred in bats. The reason, Schmidt said, is that there are simply a lot of bats around and they have a tendency to sneak into peoples homes or be found by pets.
It's important that people be knowledgeable about what to do if they encounter a bat, she said, but caution too easily becomes fear and hysteria with these often misunderstood animals. Of course it doesn't help that they are associated in our culture with horror and Halloween. In China they are symbols of happiness and joy.
Nevertheless, Schmidt agrees that the potential for rabies exposure from bats should be taken very seriously. Rabies is a viral disease of the nervous system that is always fatal once symptoms develop.
Rabies is transmitted when an infected bat bites or scratches a person or another animal. In the two Island County cases, people woke up to find a bat in the house. Since there was a potential that they were infected overnight, the people underwent the precautionary treatment.
The two rabid bats were identified as big brown bats, which are about four inches long. Schmidt said that big brown and little brown bats are the most common in the area. They roost during the day in secluded places like hollow trees, attics, crevices in rocks and under eaves.
She recently came upon a hoary bat on Camano Island. People rarely see the larger species of bats because they roost in the foliage of trees and arent attracted to buildings. They hang there and look like a leaf, she said.
Bats feast on mosquitoes
The greatest benefit of having bats in a neighborhood is insect control. The majority of bats in North America feed solely on insects. In the Northwest, bats eat a whole lot of mosquitoes and moths. A single bat can eat 1.25 times its weight in a single night. A single little brown bat can catch 1,200 mosquitoes-sized insects in just one hour.
They play a much more positive role in our environment than we realize, Schmidt said. Most of the time we dont know they are there because we cant hear them and we cant see them in the dark.
Bats arent rodents. In fact, they are most closely related to humans and other primates than to mice. Schmidt said they may have evolved from a lemur-like creature. They are long-lived mammals. One little brown bat lived to the ripe old age of 32, but the common lifespan of a big brown ban is about eight to 10 years. Unlike rodents, bat mother only has one or two baby bats, or pups, a year.
Bats arent blind. All 1,000 bat species in the world have eyes and can see quite well. Fruit- and nectar-eating bats rely completely on eyesight. Most bats that eat insect use echo-location, a type of sonar, to locate their prey in the darkness.
Bats range from a flying fox with a six-foot wing span to a rare species the size of a bumble bee.
For the Count Dracula fans: Schmidt said there are three types of vampire bats that live in South and Central America. They feed solely on the blood of animals. They dont suck blood, but lap it after biting the animal. The bite is so small that sleeping victims often dont even wake up.
With the cold weather coming on, soon the skies over Whidbey Island will be batless. Schmidt said bats either hibernate or migrate, depending on the species, during the winter because of the lack of insects to eat.
You can reach News-Times reporter Jessie Stensland at firstname.lastname@example.org or call 675-6611.