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

      2012-01-19
      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.
    • Impact of Forest Management Techniques on Bats with a Focus on the Endangered Indiana Myotis (Myotis Sodalis)

      Sheets, Jeremy J (2010-07-20)
      Understanding how forest management practices impact bats is important for maintaining a diverse bat community; rare species, especially the federally endangered Indiana myotis (Myotis sodalis) need special consideration. Bats play an important role in the environment because they prey on insects, especially pest species, and conservation of viable foraging and roosting habitats is critical. Positive and negative aspects of the implementation of forest management techniques are discussed for each bat species. Bats were sampled using mist nets at four locations in Morgan-Monroe and five locations in Yellowwood State Forests twice during each summer 2006-2008. Netting locations were adjacent to or in forest stands scheduled for experimental manipulations following conclusion of netting in 2008. This effort produced 342 bats. These data provide a baseline to understand how bats are affected by long-term forest manipulations. An acoustical survey was conducted in summer 2007 to determine forest habitats where bat species occur. Anabat II bat detectors in four habitat types,--interior forest, canopy gap, forest edge, and corridors--produced calls from 7 species, a total of 3113 calls (842 corridor, 681 forest edge, 1075 canopy gap, and 515 forest interior) during 337 sample nights. Occupancy of each habitat by each species was determined; canopy gaps were occupied most, followed by forest edge, corridors, and interior forest. These data are used to predict the response of bats to forest manipulations.
    • Summer Indiana Bat Ecology in the Southern Appalachians: An Investigation of Thermoregulation Strategies and Landscape Scale Roost Selection

      Hammond, Kristina (2014-03-18)
      In the southern Appalachians there are few data on the roost ecology of the federally endangered Indiana bat (Myotis sodalis). During 2008-2012, we investigated roosting ecology of the Indiana bat in ~280,000 ha in the Great Smoky Mountains National Park, Cherokee National Forest, and Nantahala National Forest in the southern Appalachians Mountains of Tennessee and North Carolina. We investigated 2 aspects of the Indiana bat’s roosting ecology: thermoregulation and the extrinsic factors that influence body temperature, and landscape-scale roost selection. To investigate thermoregulation of bats at roost, we used data gathered in 2012 from 6 female Indiana bats (5 adults and 1 juvenile) to examine how reproductive condition, group size, roost characteristics, air temperature, and barometric pressure related to body temperature of roosting bats. We found that air temperature was the primary factor correlated with bats’ body temperatures while at roost (P < 0.01), with few differences detected among reproductive classes in terms of thermoregulatory strategies. To understand how Indiana bats select roosts on a landscape-scale, we created a presence-only model through the program MaxENT using 76 known roost locations to identify areas important to summer roosting habitat within our study area and to identify important landscape-scale factors in habitat selection. The final model showed that Indiana bats selected roosts on the upper portion of ridges on south facing slopes in mixed pine-hardwood forests at elevations of 260-700 meters. Unfortunately, due to small sample size and the large effort required to fully investigate thermoregulation of Indiana bats in the southern Appalachians, we only were able run correlations with temperature data, and further investigation is needed to make concrete conclusions. However, the new advancements in resolution of landscape cover data and new programs in spatial modeling have enabled us to produce a large scale spatial model for identifying Indiana bat summer roosting habitat within our study area. Our findings have added to our understanding of Indiana bat roosting ecology, particularly in the southern Appalachian Mountains, and will aid land managers in effective management for this federally endangered species.