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.
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
to Dan Foster, in person, or via email. |
Wind Cave National Park Resource Management News Briefs
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