Movement modeling reveals the complex nature of the response of moose to ambient temperatures during summer

Rising ambient temperatures associated with global climate change threaten the persistence of numerous species of wildlife. Moose (Alces alces), for instance, are purported to experience heat stress occurring when ambient temperatures rise above specific seasonal temperature thresholds. These temperature thresholds, however, were established in a study that linked physiological changes in thermoregulation to ambient temperatures among a small study group of captive-reared moose. Here, we quantified movement rate of 127 moose GPS-tracked during summer from 2006 to 2010 in central Norway as a function of ambient temperature. We found little evidence of a threshold response in moose movement in relation to rising ambient temperatures during summer. We did, however, detect differences in moose movement in relation to temperature variation between daylight and twilight-night periods. Moose increased their movement in the twilight-night period when ambient temperatures were high, suggesting a compensatory response to climate variation. Our analysis identifies that dynamics of moose movement in relation to ambient temperature are complex and may not be well correlated with temperature thresholds that were previously described.