Meeting Abstract

9.2  Monday, Jan. 4  How important are water developments to the Sonoran Desert bat community? ORR, T.J.*; HYDE, T.C.; WOLF, B.O.; University of California, Riverside; University of New Mexico teri.orr@email.ucr.edu

The significant role water serves to desert vertebrates is intuitive, but in many cases remains to be fully quantified in the context of percent of water intake from a known water source. When bats from a single guild co-occur but have differing water concentrating abilities we might expect each species’ utilization of free standing water to vary in accordance with these known physiologies. However, in extreme settings physiological differences may be masked by the overall scarcity of resources. We were interested in determining the relative contribution of known sources of water to total body water of the members of a sonoran bat community. We also wished to examine how reproductive state might impact water utilization. We predicted water use would be higher in pregnant females than non-pregnant females, and highest in lactating females, but would not differ between non-reproductive females and non-reproductive males, nor males at different reproductive stages. To assess these predictions, we netted the Sonoran Desert bat community at water developments at the Kofa Wilderness Refuge in south-western Arizona for 3 summers (2007, 2008, and 2009). By labeling water sources with known concentrations of stable isotopes of hydrogen (deuterium) we assessed percent of isotopes in the plasma of bats captured at watering holes. An average of 12% of total of total body water was derived from labeled sources of water. Given an insectivorous diet that constitutes a food source between 60 and 80% water, their large usage of water developments is likely due primarily to the abiotic environmental extremes these bats endure. Interesting water use patterns were noticed in females from different reproductive stages. By directly quantifying the use of supplemented water sources by the sonoran bat community we might determine the effectiveness of current wildlife man