Transcript Slide 1

Feeding Behavior of Myotis lucifugus and Eptesicus fuscus
Holt,J.,G. Basinsky, T. Floria, R. Friesen, A. Page, and J. Paula. Department of Biology, Fitchburg State College
Introduction
Figure 2. Location of
Pisgah State Park,
Cheshire County,
New Hampshire.
Little brown bats, Myotis lucifugus, and big brown
bats, Eptesicus fuscus, (Figure 1), are common
insectivores in the Eastern United States. Big brown
bats feed primarily on beetles (Carter et. al. 2003;
Whitaker, 1972) and are considered beetle specialists
(Freeman, 1981). Little brown bats also consume
beetles but appear to be feeding generalists (Carter
et. al. 2003; Whitaker, 1972). Because fireflies are
common beetles and represent an abundant potential • Analysis consisted of percent frequency of
food source, we hypothesized that they would occur occurrence and mean percent abundance for
in the diet of both species. However, data describing each prey item.
the diets of big brown and little brown bats in New
England were limited.
Fecal samples from 71 little brown bats and 15
The goals of this research were to increase
big brown bats were analyzed. Diets of males
understanding of bat diets in New England and to
and females were similar for both species.
determine if fireflies are eaten by bats.
Little brown bats ate a variety of insects
1a
1b
including members of at least 19 families from
12 orders. However, most of the diet was
represented by 7 orders (Figure 3). Big brown
bats consumed members of at least 11 families
from 8 orders (Figure 4a). Both species of bats
also consumed unidentified insects and plant
Figure 1. Little brown1a (Myotis lucifugus) and big brown1b
(Eptesicus fuscus) bats.
remains. No fireflies were found in the diets.
Results
Methods
• Bats were captured at Pisgah State Park (Figure 2),
N.H. between May and June 2004.
• Bats were captured in a mist net, identified, and
placed in cloth bags for 15 min. to collect feces.
• Bats were identified to species, banded, and
weighed. Age, sex, reproductive condition, and
length of forearm were recorded, and bats were
released.
Neuroptera
2%
Lepidoptera
17%
Lepidoptera
2%
Hemiptera
1%
Hymenopter
a
10%
Cuconidae
1%
Unknown
15%
Unknown
1%
Scarab
13%
Curculioni
dae
11%
Carabeid
ae
19%
Diptera
3%
Elaterida
e
29%
4b.
4a.
Dysticida
e
13%
Coleoptera
79%
Figure 4. Eight most common food items eaten by big brown
bats (Eptesicus fuscus) at Pisgah State Park, NH (4a), and
within order percentages of Coleoptera eaten by Eptesicus
fuscus.
Discussion
•Little brown bats primarily fed on soft bodied
aquatic insects with Diptera, Trichoptera, and
Neuroptera constituting 40% of the total dietary
volume.
•Big brown bats preferred large hard bodied
insects (eg. Coleoptera; Figure 4).
•Both species in general, and big brown bats in
particular, may actively avoid fireflies as potential
prey while consuming other insects of similar
size and shape.
•Detailed behavioral studies of bat feeding will be
needed to investigate possible reasons for the
absence of fireflies in bat diets.
Literature Cited
Unknown
2%
Coleoptera
26%
Trichoptera
17%
Hemiptera
4%
Trichoptera
3%
Freeman, P.W. 1981. Correspondence of food habits and morphology in
insectivorous bats. Journal of Mammalogy, 62:166-173.
Whitaker, J.O., Jr. 1972. Food habits of bats from Indiana, Canadian Journal
of Zoology, 50:877-883.
Hamilton, W. J. 1933. The insect food of the big brown bat. Journal of
Mammalogy, 15:155-156.
Diptera
27%
Hymenoptera
• Fecal pellets from each specimen were placed in
5%
water and teased apart so that insect parts could be
Figure
3.
Eight
most
common
food
items
eaten
by
little
identified.
brown bats (Myotis lucifugus) at Pisgah State Park, New
Hampshire
Carter et. al., 2003. Food habits of seven species of bats in the Allegheny
plateau and ridge and valley of West Virginia. Northeastern Naturalist,
10:83-88.
Acknowledgments
We thank Kevin Austin, Christopher Cratsley, Paul Moosman, Stephanie Poisson,
Howard Thomas, Jacques Veilleux, Matthew Zanghi, New Hampshire Department
of Parks, New Hampshire Department of Fish and Game