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Vol. 43 No. 3, 2004
Flight Activity and Food Habits of Three Species of Myotis Bats (Chiroptera:
Vespertilionidae) in Sympatry
Ya-Fu
Lee1,* and Gary F. McCracken
1Department
of Ecology and Evolutionary Biology, the University of Tennessee,
Knoxville, TN 37996, USA
Ya-Fu
Lee and Gary F. McCracken (2004) Spatiotemporal distributions
in nocturnal flight activities and variations in food resource use
among the little brown (Myotis
lucifugus), northern long-eared (M. septentrionalis), and Indiana
myotis (M. sodalis) were
studied in central and northern Indiana where the 3 species occur in
sympatry. We netted pairs of these 3 species on the same nights at 4.3%
to 8.5% of the total netting sites, while all 3 species were netted on
the same night at only 1 site (~1.1%). When each species was captured
alone, the mean capture time of the little brown myotis was earlier
than those of the Indiana and northern long-eared myotis; but the 3
species did not differ in heights of capture. At sites where paired
species were caught, the mean capture time of the Indiana myotis
shifted from being no different from, to being earlier than, that of
the northern long-eared myotis; and the mean capture height of the
Indiana myotis shifted from being no different from, to being higher
than, that of the little brown myotis. Based on analyses of feces, the
little brown myotis has a more-diverse diet, feeds on more beetles of a
smaller size range, and consumes more aquatic insects than do the
Indiana and northern long-eared myotis. While the northern longeared
myotis fed primarily on beetles, moths, and dipterans, and took greater
quantities of large-sized (4~6 mm and > 6 mm) beetles, moths were
the major prey of the Indiana myotis. Variations in diets among these 3
species are consistent with their foraging behavior, are correlated to
their temporal activities, and support predictions based on previously
reported differences in their mean lengths of the maxillary tooth-row.
Key words: Activity,
Diets, Bats, Myotis, Sympatry.
*Correspondence:
Department of Life Sciences and Institute of Biodiversity, National
Cheng Kung University, Tainan 701, Taiwan. Tel: 886-6-2757575 ext.
65524. Fax: 886-6-2742583. E-mail: yafulee@mail.ncku.edu.tw
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