Greater sage-grouse juvenile survival in Utah

摘要: Greater sage-grouse (Centrocercus urophasianus; sage-grouse) adult hen and juvenile survival have been shown to significant influence on population growth rates. However, assessing the sensitivity of rates variability in has proven difficult because limited information concerning potentially important demographic rate. Sage-grouse are commonly assessed using necklace-type radio transmitters. Recent technological advances lead increased interest deployment dorsally mounted global positioning system (GPS) transmitters for studying ecology. use not thoroughly evaluated sage-grouse, leading concern that birds fitted with these may experience differentialmortality Weevaluated theeffect oftransmitter positioning(dorsal vs.necklace) a controlled experimental design necklace-style suture-backpack very high frequency (VHF) To evaluate theeffects oftemporalvariation, sex, andtransmitter type survival, we monitored 91 juveniles captured south-central Utah from 2008 2010. We instrumented 19 females backpacks, 14 males 39 necklaces, necklaces. used Program MARK analyze data. Although effects were only marginally statistical perspective, sex (P ¼0.103) transmitter ¼0.09) deemed biologically meaningful impacts survival. Dorsally appeared negatively affected daily (btransmitter ¼� 0.55, SE ¼0.32). Temporal variation sage- grouse was best described by quadratic trend time, where lowest late September overwinter. An interaction between time year resulted low point shifting within season years (27 vs. 17 Sep 2009, respectively). Overall (15 Aug-31 Mar) derived ranged 0.42-0.62 0.23-0.44 males. For all pooled, probability death due predation 0.73, reported harvest 0.16, unreported 0.09, other undetermined factors 0.02. observed 0% 6.8% crippling loss (from hunting) respectively. recommend adoption management strategies attempt shift away incorporate In addition, future studies should caution if implementing potential bias. 2014 The Wildlife Society.