By Gerri Griswold, White Memorial Conservation Center Director of Administration and Development
Gerri Griswold holds a rare beauty – an Eastern Red Bat – that lives exclusively in Maple trees and is migratory
Within seconds of speaking with Gerri, you know her mission is to spread the good word about bats. For too long, they have been misunderstood and it is her charge to set the record straight… before it’s too late.
Since 2006, the number of bats in the Northeastern U.S. has plummeted by more than 80% from white-nose syndrome (WNS), a fungus that attacks them during hibernation. In some areas of the Northeast and Canada, the death tolls have reached 90-100%. Here in Connecticut, we have lost 80-90% of our bat population. This sudden and widespread mortality associated with WNS is unprecedented in hibernating bats, among which disease outbreaks have not been previously documented. It is unlikely that species of bats affected by WNS will recover quickly because most are long-lived and have only a single pup per year. Consequently, even in the absence of disease, bat populations do not fluctuate widely in numbers over time.
The white-nose fungus was discovered in New York’s Howe Caverns in 2006 where it was likely introduced by a biologist or explorer who carried it in on shoes or gear after visiting caves in Europe, where white-nose fungus originates. Today, the fungus has been confirmed in 28 states and 5 Canadian provinces and has spread from New York all the way to Alabama and Washington State. Keep in mind, however, that some states have not allocated resources to study their bat populations so it is likely that white-nose fungus has spread even further.
The cold-loving fungus thrives in caves where bats hibernate en masse. The fungus attacks their faces and wings while in hibernation and the discomfort causes them to awaken to scratch. Many use up too much of their reserves battling the fungus and, as a result, cannot survive hibernation. Those that live can end up with brittle wings that develop holes and become less effective in catching prey.
The drop in the bat population is cause for great concern since bats are beneficial to man in several ways. Their survival is essential for a sustainable natural environment. They consume many destructive agricultural pests such as cutworm and corn borer moths, potato beetles, and grasshoppers, saving U.S. farmers billions in crop damage each year. In Connecticut, bats are the single largest predator of night-flying insects, providing a tremendous ecological service. Mosquitoes and similar “people” pests are eliminated much more efficiently by bats than by birds or bug zappers. Consider the mosquito-borne illnesses found just in the U.S.: zika, yellow fever, various forms of encephalitis, dengue, and even our beloved dogs can be stricken with heartworm from a mosquito. In tropical regions, bats pollinate flowers and disperse seeds for many commercially available plants, like almonds, avocados, bananas, figs, and allspice. Bats also have contributed to advances in navigation, vaccine and antibiotic production, birth control and fertility studies, and the development of alternative fuels like gasohol.
What can you do to help bats? Most importantly, share your knowledge with others of just how important bats are to humans. Because bats have long been incorrectly viewed as scary-looking animals with a tendency to carry rabies, their plight has received little support. You can serve as a catalyst to set the record straight through education.
As landowners and gardeners, eliminate the use of pesticides on your property and in your gardens. Although our Connecticut bats eat night flying insects, those insects have been buzzing around your lawn, yard and plants. If you are using harmful chemicals, they will ultimately make their way to the wild life in your community. In addition, minimize the disturbance to natural bat habitats around your home (e.g., reduce outdoor lighting, minimize tree clearing, protect streams and wetlands).
Having appropriate lodgings for bat colonies, which can eat up to 1.5 million insects a year, is important to maintaining ecological balance. Bat houses have been widely used in Europe for nearly 75 years. Like bird houses, they provide an artificial roost site for bats. Much has been learned in recent years about bat roosting preferences. The following factors are critical to the success of bat houses: maintaining suitable temperature ranges, the distance to food and water, the size and shape of inner roosting spaces and the roughness of clinging surfaces. Patterns for a small- and large-sized bat house can be found on the Connecticut Department of Energy & Environmental Protection at: http://www.ct.gov/deep/cwp/view.asp?a=2723&q=325964.
Install boxes where bats currently reside to greatly enhance the likelihood the bats will take to them. Bat houses attached to the sides of buildings have had the greatest reported success. Free-standing poles in open areas also work, but tree-mounted houses generally remain unused. Bat houses placed near water or wetland areas often are most successful. Installing a bat house before April improves the chance of occupancy but don’t be discouraged if bats do not immediately move into their new home. It is not unusual for a house to stand empty for at least a year before it is used.
Connecticut Bats
- Eight species of bats can be found in Connecticut:
- Little Brown Bat (Myotis lucifugus)
- Big Brown Bat (Eptesicus fuscus)
- Eastern Long-eared Bat (Myotis septentrionalis)
- Tricolored Bat (Pipistrellus subflavus)
- Silver-haired Bat (Lasionycteris noctivagans)
- Hoary Bat (Lasiurus cinereus)
- Red Bat (Lasiurus borealis)
- Indiana Bat (Myotis sodalis)
- The two most common bats in Connecticut are the little brown and big brown bats. The 6 remaining species are less common and seldom seen.
- Silver-haired, hoary and red bats are tree-roosting bats and are listed as Connecticut species of special concern.
- The state and federally endangered Indiana Bat was recently found hibernating in Connecticut.
- No confirmed sightings of the eastern small-footed bat (Myotis leibii) have been recorded here in several decades. It is a Connecticut species of special concern.
The White Memorial Conservation Center provides year-round environmental education programs for children and adults that inspire understanding, appreciation and respect for the natural world. Gerri Griswold is available to speak about the importance of bats to groups of all ages. For more information, please visit www.whitememorialcc.org, or contact Gerri at gerri@whitememorialcc.org.