Adopt a Bat: Tracking Hope in the Black Hills

A temporary radio transmitter can help researchers find a northern long-eared bat’s summer home. In the Black Hills, that signal connects a small piece of equipment to a larger question: what habitat do these endangered bats need to survive?

Why finding these bats matters

The northern long-eared bat is a forest-dependent species that typically winters in caves or mines. White-nose syndrome is its greatest threat. The fungal disease disrupts hibernation, causing bats to wake more often and burn the energy reserves they need to make it through winter.

That loss is visible in Black Hills field surveys. A study published in September 2026 in the Journal of Mammalogy compared summer captures from 2017-2019 with those from 2022-2024, after white-nose syndrome arrived. Northern long-eared bat capture rates declined sharply, along with those of several other Myotis species.

Capture rates measure survey encounters, not a census of every bat. This regional study is separate from the BHPFA-supported 2025 project. It explains the urgency behind a basic field question: where are the remaining bats spending their time?

A few days following one bat

In July 2025, Black Hills National Forest wildlife biologist Amy Hammesfahr shared a field milestone with BHPFA: researchers had successfully fitted a pregnant northern long-eared bat with a radio transmitter. They followed her for a few days before it fell off.

That brief attachment was expected. In the Forest Service’s project description, the tiny transmitter was glued onto the bat and designed to detach after a few days. It gave researchers a temporary opportunity to follow an animal that is otherwise difficult to locate.

The Forest Service and South Dakota State University were working to identify roosting habitat and better understand the species’ distribution following white-nose syndrome. BHPFA sponsored transmitters for that effort through Adopt-A-Bat support.

Field account: Amy Hammesfahr, Black Hills National Forest, July 2025.

How a signal becomes habitat evidence

A bat’s daytime resting place is called a roost. Radio telemetry gives a researcher a signal to follow toward a tagged animal. Locating that bat can turn an ordinary-looking tree into a known piece of habitat.

A few days of tracking can document use of a place; it cannot by itself establish a population trend or prove long-term survival.

Different tools answer different questions

The 2025 South Dakota Bat Management Plan explains how tracking and identification methods complement one another:

Why protecting one tree may not be enough

Summer habitat can look very different from a winter cave. Northern long-eared bats use spaces under bark, in cavities and in crevices of living or dead trees. Pregnant females and mothers raising pups need suitable places during the summer breeding season.

A separate habitat study published in September 2025 by Whittle and colleagues helps explain why roost observations matter. Working in Wyoming’s Bear Lodge Mountains, the researchers found that female northern long-eared bats’ roost choices varied with weather and reproductive stage.

A tree used during pregnancy may not meet every need later in the season.

For a forest manager, that points to the value of a range of suitable roost structures and surrounding forest conditions. Mature trees, canopy cover and different roost options can matter together. Tracking helps reveal actual use, adding detail that a forest-cover map alone cannot supply.

The Bear Lodge study offers a management lesson from related regional research. It is not a results report from the 2025 project supported by BHPFA’s transmitter funding.

Testing another tool against white-nose syndrome

Habitat research addresses where bats live. Vaccine research asks whether an intervention can reduce the harm caused by the fungus. The local project team described vaccination plans in 2025; those plans are distinct from the results of trials elsewhere.

In its August 2026 account of white-nose syndrome vaccine research, the USGS National Wildlife Health Center reports that field trials have shown lower fungal loads, less severe wing damage and higher return rates the year after treatment. Returning to a monitored site is useful evidence, but a return rate alone does not establish every animal’s fate.

In 2026, USGS moved toward colony-level comparisons. Researchers are treating a large share of bats in selected maternity colonies and comparing their persistence with nearby untreated colonies over multiple years. Monitoring includes fungal presence and emergence counts before and after young bats begin flying.

These trials are testing a possible management tool. They do not establish a local vaccination outcome or recovery of northern long-eared bats in the Black Hills.

Keep exploring the science

Tree-roost studies, cave surveys and disease trials contribute different pieces of evidence. These sources offer both accessible introductions and more technical detail:

• South Dakota Bat Management Plan, 2025The statewide reference for species, threats, survey tools and management priorities. Printed pages 65-66 explain tracking and marking methods.
• Context matters: habitat choices in an endangered forest batThe 2025 Bear Lodge Mountains study connects roost selection with weather and reproductive stage. A useful next step for readers interested in forest management.
• Changes in summer bat captures in the Black Hills after white-nose syndrome invasionThe 2026 regional paper explains its survey comparisons and what capture data can tell researchers.
• Vaccine fieldwork on San Juan IslandA National Park Service story follows a trial involving a different species and colony in Washington, making the comparison process easier to picture.
• Bats at Jewel Cave National MonumentConnect the science to a Black Hills park, its hibernating bats and visitor guidance.