Evaluating Survival of Greater Sage-Grouse Chicks in Strawberry Valley, Utah, by Use of Microtransmitters: Does Handling Time Negatively Influence Survival Rates?

Research indicates that low nest success and juvenile survival may be factors contributing to Greater Sage-Grouse population declines. Recent technological advances in microtransmitters have allowed researchers to monitor individual chicks and broods. We initiated a chick survival study in 2006 and used microtransmitters to (1) examine the viability of using microtransmitters on chicks to assess survival, including the effect of handling time during the suturing process; (2) estimate overall chick survival; and (3) compare chick survival in the Strawberry Valley population to other published reports. We used a known-fate model in program MARK to estimate ĉ (overdispersion), weekly survival rates, and 49-day survival of radio-marked chicks. Chick survival rates were lowest during the initial 3 weeks of life, after which point weekly survival stabilized. Survival over 49 days was estimated at 0.25 (SE 0.10) and was comparable to estimates from other populations. Handling time was negatively associated with chick survival, and chicks were 2 times more likely to survive to 49 days when handled for only 5 minutes instead of 19 minutes. We recommend that researchers be judicious in using microtransmitters and make every effort to reduce handling time during transmitter attachment.