Bats: World's Only Flying Mammals
Most Species Control Insect Pests While Others Pollinate Plants
Long misunderstood and feared, bats are a vital part of the environment. They are beginning to get protection as habitat loss and pesticide use threatens some species.
Despite the sensationalism surrounding vampire bats, only ten species of bats are actually carnivorous, with only three of those ten being vampire bats. A few other bats are fruit or nectar eaters, acting as seed dispersers and plant pollinators. The rest of the bats, nearly 70% of the thousands of species , are insectivores that play an important role in controlling mosquitoes, moths and many crop pest species.
Interestingly, one of the carnivorous species has evolved to eat fish. The other carnivores tend to prey on small birds and mammals or even other bats. All carnivorous bats eat insects as well.
Fruit eating bats tend to be larger and have a better developed vision and sense of smell than the insectivorous bats, which rely more on echolocation. Many of the fruits these bats eat are not easily accessible to birds, making bats the key seed dispersers.
Another small group of bats have become nectar eaters, with research suggesting that some flowers have evolved into a shape that reflects bat echolocation making it easier for the bats to find the flowers.
Bats and Rabies
Once feared as a rabies vector species, it is now known that fewer than 1% of bats will contract rabies. Most of them will sicken and die quickly, not becoming a threat to humans. This does not mean that caution shouldn’t be used around bats. It is still best to exclude them from the home to prevent accidental contact. Bat boxes on the property will provide them with an alternate roost.
Bats, Insects and Pesticides
The majority of bats are insect eaters. In particular they tend to prey on species such as mosquitoes, moths and many species that damage crops. Pesticides are affecting bats in two ways. Killing of large numbers of insects reduces the prey species available to the bats. And bats forage in the evening, a prime time for spraying crops. The bats may be killed immediately upon exposure to the insecticide.
There is also some concern that the use of neonicotinoid pesticides may be causing abnormal behavior in both bats and bees. The role of these pesticides in bee colony collapse disorder and the bat die off in the eastern US is being examined very closely.
Habitat Loss and Disturbance Affect Bats
Humans are affecting bats in other ways. Deforestation results in the loss of roosting sites, especially for tree dwelling species. Entering caves, particularly when bats are hibernating, can disturb the colony, causing them to waste precious energy. In maternal colonies, disturbance can cause young bats to be abandoned or to lose their grip and fall to their death.
Loss of riparian areas such as riverbanks and lakesides means loss of insects for food and fresh water for the bats to drink. When combined with aquatic pollution, the danger to bats is clear.
How to Help Bats
There are some things that everyone can do which will help bats
- Put up a bat house
- Plant native plants that attract night insects
- Put a bat light in the garden to attract more of those night insects
- Don’t use pesticides
- Don’t enter caves without determining whether bats are present
- Leave a wildlife corridor between wooded areas
Bats have proven to be an ally of man. Its time man returned that favor.
Photo Credit: J P K Witter
