Last updated: November 20, 2019
Article
Bat Population Monitoring in Petersburg National Battlefield
NPS photo / Morgan Ingalls
Why is the Petersburg National Battlefield interested in bats?
Bats are an important part of ecosystems and food webs. Though some species of bats feed on fruit, seeds, or pollen, the species that live in Virginia are insectivores. They consume huge numbers of insects every night, filling a unique ecosystem role as nocturnal insect predators. Unfortunately, a new disease called white-nose syndrome is affecting bats across the United States. To better protect bats, biologists are studying how local bat populations are changing.
Research Highlights
- Recent monitoring detected 11 species of bats, including two federally threatened or endangered species.
- White-nose syndrome has negatively affected several species of bats in the park.
- Overall, bat activity was highest in the Eastern Front, but Five Forks also had relatively high activity of several rare species.
- Little brown bats, a state endangered species, may be reproducing in the park.
How do biologists study bats? What have they learned about bats in the park?
Biologists have creative ways of studying these animals. Bats use echolocation to navigate and catch insect prey during the dark of night. People can’t hear these bat calls, so biologists use special microphones, called acoustic detectors, to record the sounds. Specific bat species can then be identified by analyzing the bat calls.
From 2016-2017, scientists used acoustic detectors to document 11 species of bats in the park. Generally, the most bat activity was observed in the Eastern Front. The lowest activity occurred at Five Forks.
The most commonly detected bat species overall was the big brown bat (Eptesicus fuscus)—this species is less susceptible to white-nose syndrome than many other species. Interestingly, the little brown bat (Myotis lucifugus), a state endangered species which is extremely susceptible to the disease, was also relatively common. Despite generally low bat activity at Five Forks, an exception occurred at one site that had very high levels of little brown bat activity. This suggests that little brown bats may be reproducing there.
Researchers are also capturing bats and using tiny radio-tracking devices to follow bats to important habitats. Park managers can then better protect these areas. For example, some bats return to the same breeding locations every year, including specific hollow trees, buildings, or snags. Limiting disturbance to these areas is essential to maintaining bat habitat.
What about other rare bat species?
During the summer, there are four rare bat species that can be found in the park. In addition to the little brown bat, the tri-colored bat (Perimyotis subflavus), the Indiana bat (Myotis sodalis), and the northern long-eared bat (Myotis septentrionalis) are also present. The latter two are protected by the Endangered Species Act and all three were rarely recorded by the acoustic detectors. This indicates that they are not common. All of these rare species are sensitive to white-nose syndrome.
These rare bats spend their summer days roosting in tree cavities and snags, under tree bark, or in buildings. At night, they emerge to feed across the park’s landscape. During the fall, these species of bats usually travel to caves or mines, where they hibernate for the winter. In these caves and mines, they can contract white-nose syndrome and die.
NPS photo
What is the National Park Service doing to help bats?
The data being collected on bats will help park managers conserve bats and their habitat. Protecting hollow trees and snags where bats raise their young and preserving mature hardwood forests will help reduce the impacts of the disease. White-nose syndrome remains an extraordinarily dangerous threat to bat populations—sadly, some species may ultimately disappear from the region.
Want to learn more?
For more information:
Contact Natural Resource Manager Tim Blumenschine.
Download a printable pdf of this article.