Masters Theses

Date of Award

12-2004

Degree Type

Thesis

Degree Name

Master of Science

Major

Wildlife and Fisheries Science

Major Professor

Lisa I. Muller

Abstract

Bats are an important component of forest ecosystems. The bats present in southern forests use echolocation to consume great numbers of insects each year. Of the 22 bat species in the southeastern United States, 14 are known to occur in Tennessee. The gray bat (Myotis grisescens) and the Indiana bat (Myotis soda/is), are endangered. However, there has been limited research on bats in Tennessee. This study was designed to identify diversity and distribution of bat species on Chuck Swan Wildlife Management Area (CSWMA), Tennessee. During summer (late May through mid August) 2002 and 2003, 74 and 85 locations, respectively were randomly chosen at CSWMA and actively sampled for bat activity using theAnabat II system to record echolocation calls of bats. The Anabat system transforms those calls into frequencies audible to humans. The calls can then be analyzed in the program Analook. Echolocation calls of most bats are species specific. Active sampling occurred for 20 minutes at each sampling site. Bat detectors were moved to the direction of the bats as they were heard. At each site, habitat type, slope, aspect, temperature, % cloud cover, wind, % canopy cover, % shrub cover, litter depth, number of snags, number of trees with exfoliating bark, and whether or not water was within 10 m of the site was recorded. During fall, 5 September through 15 November 2003, Anabat II detectors were placed in waterproof containers at 2 of the entrances to 3 caves. Sites were continuously monitored from 8:00 p.m. to 6:00 a.m., except for days when rain was forecasted by the National Weather Service. Eight different species of bats were identified by echolocation at the active sampling sites. Species included big brown bats (Eptesicusfuscus), silver-haired bats (Lasionycteris noctivagans ), eastern red bats (Lasiurus borealis ), hoary bats (Lasiurus cinereus), little brown bats_(Myotis lucifugus), Indiana bats, evening bats (Nycticeius humera/is), and eastern pipistrelles (Pipistrellus subflavus). Fisher's exact tests and Multivariate Analysis of Variance were used to determine species habitat relationships. Hoary bats occurred in different habitat types (P<0.001) and canopy cover {P<0.001) than all other species. Little brown bats differed from eastern red bats (P=0.038). Hoary bats occurred in less shrub cover than big brown bats, eastern red bats, silver-haired bats, evening bats, and eastern pipistrelles. Seven species of bats were identified at the cave sites, including big brown bats, eastern red bats, hoary bats, little brown bats, Indiana bats, evening bats, and eastern pipistrelles. As temperatures fell during the fall, bat activity greatly decreased at cave sites. Individual bat species use many different habitat types. A variety of areas are required for day and night roosts, foraging areas, and summer and winter roosts. It is important for CSWMA to remain diverse in habitat type and structure in order to provide suitable habitat for many bats species.

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