Effects of Ectoparasites and Reproductive Class on Roost-Switching and Foraging Behavior of Indiana Bats (Myotis sodalis)

摘要

Ectoparasites of bats have been known to cause harm to their hosts and to affect roost-switching. Little research exists on effects ectoparasites may have on roosting and foraging behavior of the federally endangered Indiana bat (Myotis sodalis). From 2008 through 2010, I collected ectoparasite data and documented roost-switching and foraging behavior of Indiana bats on habitat restoration lands owned by the Indianapolis International Airport (IND) in central Indiana. I tested for differences in roosting and foraging behavior between bats with varying ectoparasite loads, and for differences in ectoparasite load, roost-switching frequency, and foraging behavior between different reproductive classes of Indiana bats. I used the volume of ectoparasites of each Indiana bat when analyzing data. I found a significant difference in roost-switching frequency and ectoparasite volume between reproductive classes. Neither reproductive class nor ectoparasite load significantly affected any aspect of foraging behavior. Indiana bats in this study apparently maintained moderate loads of ectoparasites which may not affect foraging and roosting, but the insignificant results found in this study may have been due to a small sample size. The significant difference in roost-switching between reproductive classes likely demonstrates variation in bat thermoregulation. Lactating females and pregnant females have a higher need for group thermoregulation and switch roosts less frequently than post-lactating females and volant juveniles. Because ectoparasites have been found to increase in maternity colonies, volant juveniles and post-lactating females may disperse from the main colony roost and switch roosts more often to avoid higher intensities of ectoparasites.