Investigating Roosting Behaviors of the Hawaiian hoary bat (Lasiurus cinereus semotus) on Hawai'i Island
Sean Moura1, Kristina Montoya-Aiona2, Frank Bonaccorso2
1Hawaiian Electric Company, Honolulu, HI. 2U.S. Geological Survey, Pacific Island Ecosystems Research Center, Hawaii Volcano National Park, Hawaii


II. Building the Future


The Hawaiian hoary bat (Lasiurus cinereus semotus), a federally and state listed endangered subspecies, is the only extant native terrestrial mammal in the Hawaiian archipelago. It is an insectivorous, solitary and foliage-roosting species that generally roosts alone or in mother-pup family groups. We observed roosting behavior of five solitary adults using thermal imagery and surveillance video from May 24th to September 14th of 2017. We recorded a total of 56 hours of video at three separate day roost trees. We characterized behavior of bats at day roost sites and quantified time spent sleeping, grooming and other arousal events. Additionally, we collected body temperature (fur/skin temperature) data and surrounding foliage ambient temperature data at well shaded roost sites. Hawaiian hoary bats typically enter shallow torpor during the day while maintaining a mean differential above ambient temperature of 6.0 ± 1.28 ˚C.  Spikes in body temperature can be associated with arousal from sleep and activity such as urination or grooming. This study represents a novel approach to studying the roosting behavior of L. c. semotus and in the future we hope to study mothers with pups during the critical maternity season.