NATURE NOTES – Number 37 January 28, 2022
Introduction:
We often think of winter as a time for many animals to go into hibernation, such as bears, but I’m willing to bet many scouts have not thought about this group of critters that is also hibernating:
Our Current Topic: Bats
Bats have a bad reputation. They are often pictured as some evil creature swarming out of a cave, or as Halloween decorations, but in reality they are valuable part of the ecosystem. Anything that eats half of its body weight in insects each night can’t be all bad. Bats are the only true flying mammal. Their unique arrangement of fingers and skin serve as wings allow them very rapid and agile flight. Worldwide, there are over 1000 species of bats. Some are fruit-eating bats, but all of Virginia’s 17 species are insect-eating bats. Some of these are restricted to very limited areas (mostly caves). All of them hibernate in the winter when insects are not available. Old houses, attics and chimneys are also favorite roosting sites in more urban areas. Bats are divided into “cave bats”, favoring caves and rock crevices for roosting and hibernation, and “tree bats” that use trees. Some species will use both. They locate their food using a special sensory system called “echolocation” to maneuver through the dark. This system, similar to radar, emits a high-pitched sound that bounces off of objects and returns to the bat to outline the distance, size, shape, etc. of the surroundings – including the insects they seek.
Many bats are declining due to several factors, including disturbance of habitant by humans and the low rate of reproduction (often only one or two “pups” a year) that makes it difficult for the species to rapidly recover from population declines. Bats in general live a long time, some individuals up to 20+ years. There are two current threats to the well-being of bat populations. One is the promotion of wind farms as a source of energy. Some studies have shown that the turning turbines above ridges are a threat to bats. As a result, agreements have been reached between the wind tower operators and environmental regulators to limit the times the turbines can be operated, posing less danger to the bats. Another threat is the white-nose syndrome (WNS), a fungus that affects bats. For years, Virginia had dodged WNS, but it’s now here. This is believed to have been spread by boots of spelunkers that visited infected caves out-of-state. The Little-brown bat and the Tri-colored bat have suffered a decline of over 90% due to WNS.
Several human diseases have been associated with bats, including rabies. Bats should NOT be handled. Dispose of any bat remains with caution, using gloves and long-handled tools. Bat bites can be difficult to detect, so if you have been in close proximity of bats, have someone check your scalp and neck for any bite marks. Bat guano, which can be found in large quantities in areas inhabited by roosting bats, such as attics or barns, can contain a microscopic fungus that can cause a serious human lung disease. Also, as we have all heard, the current COVID-19 is alleged to have originated in Asian bat populations. Identifying bats can be somewhat difficult. Here is a list of some of the species found in western Virginia that might help you if you want to pursue this. For more details, use the Virginia Department of Wildlife Resources web site: dwr.virginia.gov/wildlife/bats. A scan of the notes below shows the diversity in bat habitats and habits.
Virginia Big-eared Bat. 4” long. Mostly a moth feeder, this brownish bat is found in very limited locations in the western edge of Virginia. It is the official state bat. On Federal Endangered Species list.
Little-brown Bat. 3” long. Very common summer bat that feeds over water. Roosts in old buildings, bridges, and trees. Hibernates in caves and mines in western part of the state.
Eastern Red bat. 4-5” long. The most common tree bat that is “Irish Sitter red”. Common around lights in suburban areas. Hibernates in log piles.
Northern Long-eared Bat. 2-4” long. A cave bat similar to the Little-brown bat. Found throughout the state in various habitats.
Big-eared Bat. 5” long. Wide distribution in Virginia. Locally abundant. Roosts in old buildings.
Tri-colored Bat. 3” long. Statewide. An early evening feeder at treetop level. More common west of the Blue Ridge. Solidary hibernator in caves, it spends summers roosting in buildings and hollow trees.
Evening Bat. 3-4” long. A small dark brown tree bat found east of the Blue Ridge. Not a lot of detail is known about this bat.
Indiana Bat. 3-4” long. Similar to Little-brown bat, but with multi-colored fur. Hibernates in large colonies in a very few caves in western Virginia. Federally Endangered Species.
Silver-haired Bat. 4” long. A solitary tree bat that migrates through the state. Found near waterways.
Northern long-eared. 3” long. A cave bat similar to the Little-brown bat. Throughout Virginia. Impacted by WNS.
Opportunity
Bats are easier to see than many expect. They can often be seen just before dark as they twist and turn searching for their dinner in urban, suburban, and rural areas. Remember that bats are constantly beating their wings and not alternating beats with soaring like evening birds. Just pointing out a bat, or a whole colony, during an outing can be an eye-opener for young scouts.
Building bat boxes and placing them in the right place is a worthwhile project that scouts can do. Placement and use can be tricky, so go to the Virginia DWR web site for some good initial guidance before getting started.
Again, our goal here is interest scouts in nature. If bats will do that, GREAT! Use this info during an outing to open that door to nature. Thanks for reading NATURE NOTES. Contact me at:
