Population characteristics, space use and habitat selection of two non-migratory caribou herds in central Alaska, 1994 - 2009

Abstract

Conservation and management of Alaska’s caribou (Rangifer tarandus granti) herds are important for ecological, cultural, social, and economic reasons.  While most research is directed towards the large migratory herds, smaller herds that may or may not be migratory can be an equally valuable component of the state’s faunal resources; but for many of these smaller herds, basic information on herd size, demographics, space use and movements is lacking.  We compiled Very High Frequency (VHF) telemetry data collected from 1994 - 2009 on 2 such herds in central Alaska, the Hodzana Hills Herd (HHH) and the Ray Mountain Herd (RMH) and estimated abundance, survival, resource selection and seasonal home ranges to inform future management of these herds.  We found that both herds were relatively small and stable with approximately 1000 – 1500 individuals; annual survivorship of adult females was high (93% and 94% for RMH and HHH, respectively) and comparable to other stable or increasing herds in Alaska.  Both herds were non-migratory maintaining seasonal ranges with substantial overlap.  Additionally, despite their close proximity, we did not document any exchange of individuals between the 2 herds.  Their spatial separation may be partly due to a strip of non-preferred habitat that somewhat parallels the Dalton Highway.  While the telemetry data we used were not originally collected for the purpose of this study, careful compilation and application of appropriate analytical techniques allowed us to glean important characteristics of these herds that will be of value to regulatory and management agencies in the future.