Meeting Abstract

80.1  Tuesday, Jan. 6  The dark side of climate change: warmer and drier weather patterns significantly curtail reproductive efforts for western bats. ADAMS, Rick A.; Univ. Northern Colorado, Greeley rick.adams@unco.edu

Climate warming is occurring at an accelerated rate in western North America. This is particularly true at higher elevations throughout the Rockies Mountains and Pacific Coastal ranges whereby mean monthly temperatures, precipitation levels, and water availability have already been significantly affected. In this talk I provide data suggesting that bats provide a bellwether for measuring the effects of ecosystem temperature shifts and loss of water resources. In 2006, we measured visitation patterns to an artificial water source of PIT-tagged lactating and nonreproductive female M. thysanodes and found significance differences between the numbers of drinking passes between these two groups (Nlac = 236, Nnonrepro = 18; Wilcoxon rank-sum, p = 0.0001), with lactating individuals visiting 13 times more often. From these data we construct a decay model for assessing the effects of climate-induced declines in natural water resources on reproductive success of bat populations in areas of western North America currently experiencing climate warming. I take this analysis further by incorporating overall climate data for Colorado on mean temperature, mean precipitation, and mean stream discharge rates over the months of June, July, and August as well as winter snowpack averages and compare these data with a 12-year cumulative record of captures (n = 2,123) and the reproduction status of female bats during that time. Significant declines (p = 0.001) are evident in frequency of female reproductive success as correlated with higher monthly mean temperatures, lower precipitation, and lower stream discharges.