Timing and geography structure heat wave and drought effects on avian community dynamics

Thomas Albright, University of Nevada, Reno, talbright@unr.edu (Presenter)
Chadwick Rittenhouse, University of Connecticuit, cdrittenhous@wisc.edu
Anna Pidgeon, University of Wisconsin-Madison, apidgeon@wisc.edu
Patrick Culbert, University of Wisconsin, pdculbert@wisc.edu
Murray Clayton, University of Wisconsin-Madison, mkc@plantpath.wisc.edu
Curtis Flather, USFS/Rocky Mtn., cflather@fs.fed.us
Brian Wardlow, University of Nebraska-Lincoln, bwardlow2@unlnotes.unl.edu
Volker Radeloff, University of Wisconsin-Madison, radeloff@wisc.edu

Climate warming and increased variability in temperature and precipitation are expected to produce more intense heat waves and droughts in the 21st century over much of the Earth. We sought to elucidate the fundamental, but poorly understood, effects of these extreme weather events on avian communities across the conterminous United States. Specifically, we explored: 1) the effects of timing and duration of heat and drought events, 2) the effects of jointly occurring drought and heat waves relative to these events occurring in isolation, and 3) how effects vary among functional groups related to nest location and migratory habit, and among ecoregions with differing precipitation and temperature regimes. Using mixed effects models, we quantified the effects of heat waves and droughts on US avian communities using 2000-2008 data from the North American Breeding Bird Survey, the remote sensing instrument MODIS, and a network of precipitation measurements. We found large changes in avian abundances related to 100-year extreme weather events occurring in both breeding and post-fledging periods. We also found that jointly-, rather than individually-occurring heat waves and droughts were both more common and more predictive of abundance changes. Declines in avian abundance following heat waves and droughts were largest in the arid southwest, and among ground-nesting birds and Neotropical migrants. These results indicate the importance of functional traits, timing, and geography in avian responses to weather extremes.

Presentation Type:  Poster

Session:  Global Change Impact & Vulnerability   (Tue 11:30 AM)

Associated Project(s): 

• Pidgeon, Anna: Effects of fire, extreme weather, and anthropogenic disturbance on avian biodiversity in the United States ...details

Poster Location ID: 108