Bat foraging in winter vs summer

Unlike bats in cold northern regions, bats in the South can be active year-round. However, most studies of bat habitat use have been conducted during the summer, Little is known about winter bat habitat.

In summer and winter 2018 and 2019, USDA Forest Service scientist Susan Loeb, Clemson University graduate student Kyle Shute, and his professor, David Jachowski, staked out 121 sites in upland forests, bottomland forests, fields, ponds, and salt marshes in the Coastal Plain of South Carolina to determine if bats change their foraging habitats between summer and winter. They were listening to the nightly activities of four bat species, each threatened by habitat loss in this rapidly urbanizing area.

The team found that northern long‐eared bats (Myotis septentrionalis) and southeastern myotis (Myotis austroriparius) did not change habitats and used sites near hardwood or pine forests that had fresh water year‐round.

During the summer tricolored bats (Perimyotis subflavus) used all available habitats equally – but during the winter, they were much more selective about where they foraged. They used bottomland forests, fields, and ponds more than they used salt marshes and upland forests.

Northern yellow bats (Lasiurus intermedius) also changed their preferred foraging habitats between seasons. In summer they used sites close to fields and water: fresh water, salt marshes, or ponds. In winter they avoided salt marshes and foraged in fields, ponds, or bottomland forests.

The study shows that it is important to study bats’ habitat use throughout the year, as some habitats are important during different seasons. It further shows that conserving bottomland forests, ponds, and salt marshes is important to year-round bat conservation in the Coastal Plain of South Carolina.

Read the research in The Journal of Wildlife Management. For more information, email Susan Loeb at susan.loeb@usda.gov.