• Wind Cave National Park - Two Worlds

    Wind Cave

    National Park South Dakota

Resource Ramblings 2004-09

Townsend's Big-eared Bat - Plecotus townsendi

Townsend's Big-eared Bat - Corhynorinus townsendii

NPS Photo

Wildlife of the night abound at Wind Cave National Park

As the summer season winds down, we thought you might be interested in some Park research begun in August. Mist nets were set up at five locations in the
Townsend's big-eared bat. Beaver Creek canyon, Reeve’s Gulch, and at the Herp Pond within the park. The people conducting the research were Dr. Cheryl A. Schmidt, Shauna R. Marquardt and Dan Foster. Other people have helped as well. This is being completed for two purposes. First, as a part of the National Park Service Biological Inventory, we desired to document all of the species suspected of residing in, or utilizing the park. Second, we desire a better understanding of the effects of habitat manipulation, particularly through the use of fire, on bat population dynamics and their insect prey base.

The availability of areas for bats to hibernate, proximity to foraging areas, abundance of water sources, and an abundance of summer and maternity roost sites makes the Black Hills excellent habitat. A number of migratory species, such as silver-haired bats, are documented to use the Black Hills for summer activities, including maternity roosting. With this, the Black Hills represents an island ecosystem within the mixed- and short-grass prairie/pastureland matrix of western South Dakota and eastern Wyoming.

 
Red Bat - Lasiurus borealis

Red Bat - Lasiurus borealis

NPS Photo

During the first round of surveys, we were able to document 10 of 11 species of bats suspected as users of the park’s habitats. All of these species are listed as being residents in the Black Hills, but not all had been documented in the park before. In addition, we were able to add a new species to the park’s species list, red bat. The following is a list of the species found:

  • Townsend’s big-eared bat (Corhynorinus townsendii)
  • Big brown bat (Eptesicus fuscus)
  • Silver-haired bat (Lasionycteris noctivagans)
  • Red bat (Lasiurus borealis)
  • Hoary bat (Lasiurus cinereus)
  • Small-footed bat (Myotis ciliolabrum)
  • Little brown bat (Myotis lucifigus)
  • Northern long-eared myotis (Myotis septentrionalis)
  • Fringe-tailed bat (Myotis thysanodes)
  • Long-legged myotis (Myotis volans)

In addition, acoustic surveys were conducted at sites to collect travel and search calls, as well as feeding buzzes. Without using their vision (which they have), many bats can find food and avoid obstacles with great ease, by use of echolocation or sound waves. An Italian scientist, Lazarro Spallanzani, living in the late 1700s, helped us begin to understand how bats operated in the dark. He placed a bat and an owl in a semi-dark room and found that both could orient well in low light. In complete darkness, the bat flew effortlessly while the owl bumped into objects in its flight path. When he placed a sack over the bat's head, it too, became disoriented. Spallanzani concluded that bats used a "sixth sense" to orient and after revising his experiments, concluded that bats could “see” using their ears and sound. The sounds we recorded will be analyzed this fall and help in developing an electronic library of language for each species of bat within the park and Black Hills.

Four species documented (Northern long-eared myotis, Fringe-tailed bat, Silver-haired bat, and Townsend’s big-eared bat) are listed as South Dakota species of concern and four (Townsend's Big eared bat, Fringe-tailed myotis, Long-legged myotis, and Western Small-footed myotis) are listed as species of concern by the U.S. Fish and Wildlife Service.

So what is so important about bats and why should we care? Well, consider these facts:

  • A single Little brown bat can catch 1,200 mosquito sized insects in one hour.
  • A red bat eating 100 moths may prevent egg-laying that produces 25,000 new caterpillars that may attack crops.
  • Silver-haired, long-eared, and other bats feed on a variety of forest insects, keeping them in check.
  • A colony of 150 big brown bats can protect local farmers from up to 33 million or more rootworms in a summer.
  • Bat droppings in caves support entire ecosystems of unique organisms, including bacteria useful in detoxifying wastes, improving detergents, and producing gasohol and antibiotics.

Bats are an integral part of the ecosystem, filling a niche not utilized by other species. However, the most significant threat to bat survival and their vital ecosystem role are human persecution and loss of habitat. Vandalism and disturbance of roosting caves, loss of tree snags, and careless use of pesticides all seriously threaten bat populations.

Comments and feedback about Resource Ramblings are encouraged and can be made via email.

Did You Know?

Stemless Hymenoxys

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