The lab is tackling many projects associated with the overarching goal to understand the overall impacts of the devastating disease white-nose syndrome (WNS) on the southeastern bat community. These projects currently include:
Multi-scale habitat selection of tri-colored bats (Perimyotis subflavus)
Little has been published on the spatial ecology and summer habitat requirements of the tri-colored bat, Perimyotis subflavus. P. subflavus utilizes forest landscapes as a summer habitat. Forest management practices have the ability to alter the selected landscape and lead to the depletion of a declining species. We will assess multi-scale habitat selection of P. subflavus and impacts of forest management between sexes. We are specifically interested in 1) roost site selection and fidelity, specifically tree characteristics and 2) home range use, specifically home range size and forest age and management history. We predict tree characteristics and forest history are driving factors that influence habitat selection due to impact on foraging resources. We expect that due to physiological constraints (pregnancy, pups, lactation, predator avoidance) females will differ from males in habitat selection at both scales. This work is lead by graduate student Sarah Zirkle.
Shifts in the reproductive community pre- and post-WNS
Research has shown shifts in the peak proportion of pregnant females to later in the summer in areas where WNS has devastated susceptible populations. These shifts are attributed to the increased energetic demands of WNS during winter and can be problematic if juveniles lack adequate time to gain fat stores before hibernation. At elevations where winter is short and mild, and thus energetic demands of hibernation are low, WNS-susceptible species should not delay reproduction at the same rates compared to elevations with longer, more intense winters. Therefore we predict a shift in the peak proportion of pregnant females to later in the summer in post-WNS populations compared to pre-WNS populations; however, we expect the magnitude of this shift to be driven by elevation and winter severity. Since the timing of pregnancy will drive juvenile growth rates, we also predict a shift in the timing in which post-WNS juveniles reach their maximum adult weight before hibernation. Alternatively, populations build up fat store relative to winter duration and thus we would see the same trends in reproductive condition and juvenile body mass in WNS-susceptible species, regardless of differences in elevation. This work is lead by graduate student Sarah Krueger.
Relationships between forage availability and the bat community
Insects serve as the base for most food chains and studying the relationship with high trophic predators can shed light on poorly understood factors that could lead to improved riparian area management and bat species conservation. We expect a relationship between insect biomass and bat species richness. We hypothesize that insect biomass is driven by water quality and thus drives bat species diversity. We therefore predict a positive relationship between percent insect biomass composed of pollution intolerant aquatic insects (EPT) and bat species evenness. Previous research has shown certain bat species are more sensitive to water quality, such as (Eptesicus fuscus) and others such as tri-colored are not as impacted. If that is the case, we would expect a greater effect of tolerant insect biomass on bat species specific abundance. We also hypothesize that bat species richness is driven by the availability of forage insect species and therefore predict a positive relationship between % biomass composed of bat forage species and bat species richness. This work is lead by graduate student Trevor Walker.