Meeting Abstract

62.1  Friday, Jan. 6  Seasonal changes in energy expenditure, corticosterone and behavior in free-living red crossbills, Loxia curvirostra CORNELIUS, JM*; HAHN, TP; CHAPPLE, TK; WILKELSKI, M; Max Planck Institute of Ornithology; University of California, Davis; Max Planck Institute of Ornithology; Max Planck Institute of Ornithology cornelius@ucdavis.edu

Energy is the currency of life, where a surplus allows survival and reproduction and a long-standing debt leads to death; yet monitoring of energy expenditures in free-living animals has been relatively limited by available technology. Radio transmitters that have been specially modified to detect heart rate, however, allow for real-time estimation of energy expense in free-living, behaving animals. Red crossbills live at northern latitudes year-round and breed opportunistically throughout much of the year. They therefore offer a unique opportunity to examine the eco-physiology of different life cycle stages under drastically variable seasonal conditions. Here we present heart rate data, corticosterone levels and behavioral ecology of free-living, non-breeding red crossbills in the summer and winter, as well as molting red crossbills in the autumn. We discuss these variables in the context of red crossbills’ unique opportunistic and nomadic annual schedules and the highly seasonal conditions of our field site in Grand Teton National Park.