Bat Population Monitoring in Richmond National Battlefield Park

Northern long-eared bats (Myotis septentrionalis) are one of the rarest bats in the park. Here, a biologist examines a northern long-eared bat for wing damage from white-nose syndrome. By studying what habitats these bats need, the park can better protect this federally threatened species.

NPS photo / Morgan Ingalls

Why is the park 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 in the park, including two federally threatened or endangered species.
• White-nose syndrome has likely negatively affected several of these species.
• Bat activity was relatively high, particularly at Cold Harbor and Gaines Mill.
• Little brown bats (Myotis lucifugus), 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 unique animals. Bats use echolocation to navigate and catch insect prey during the night. People can’t hear these bat calls, so biologists use special microphones, called acoustic detectors, to record the sounds. Individual 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.

Figure 1. Activity levels of bat species in Richmond National Battlefield Park recorded by acoustic detectors, 2016-2017.

The most commonly detected bat species 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, a state endangered species which is susceptible to the disease, was also relatively common. One area in Gaines Mill had 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 or snags. Identifying these locations and limiting disturbance to these areas can help bats.

What about rare 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 were rarely recorded by the acoustic detectors. All of these rare species are sensitive to the disease.

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.

During studies in 2016-2017, bat activity across the park was relatively high. Particularly high levels were observed at Cold Harbor (above) and Gaines Mill.

Photo courtesy of Ausra Huntington.

What is the park doing to help bats?

The data being collected on bats will help park managers conserve bats and their habitat. Protecting trees and buildings 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.

What to learn more?

• Bats in national parks
• White-nose syndrome response team
• Bust some bat myths!

For more information:

Contact Kristen Allen, Chief of Natural and Cultural Resources

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