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Dispersal ecology of greater sage-grouse in northwestern Colorado: evidence from demographic and genetic methods
Dispersal ecology of greater sage-grouse in northwestern Colorado: evidence from demographic and genetic methods

​​​​​​​​​​​​​​​​​​​Led By

Anthony D. Apa​ in collaboration with Thomas R. Thompson, Ph.D.​ and Kerry P. Reese, Ph.D. (University of Idaho)

Study Area

Moffat County

Project Status

Completed​

Research Objectives

  • Evaluate the feasibility of hatching chicks in captivity to augment surrogate wild females with broods.

  • Investigate the natal dispersal of sage-grouse using demographic and genetic methods.

  • Investigate chick survival from hatch to 1 year and assess juvenile recruitment.​

Project Description

(Portion of Abstract from Dissertation) The greater sage-grouse (Centrocercus urophasianus; here after sage-grouse) has undergone dramatic population declines over the last 25 years due to habitat fragmentation, and degradation. These declines and the subsequent loss of habitat, necessitates knowledge concerning the juvenile ecology of sage-grouse and information on natal dispersal (essentially unknown for sage-grouse). The overall objectives were two-fold: 1) to assess the feasibility of actively collecting and hatching sage-grouse eggs from wild radiomarked sage-grouse and rearing chicks from 1-10 days of age before augmenting wild sage-grouse broods, and 2) to investigate natal dispersal in greater sage-grouse through both demographic and genetic methods. We investigated wild chick and their captive-reared cohort survival from hatch to 1 year of age in the Axial Basin and Cold Springs Mountain study areas in northwestern Colorado, 2005-2007. Model averaged estimates of brood and chick survival indicated that survival varied both temporally and spatially. Sage-grouse were monitored to determine survival and recruitment of juveniles from 1 September – 31 March. Survival from September through March was similar for all juveniles, but varied by month, study area, and gender. Median dispersal distance was greater for juvenile males compared to females. Patterns of dispersal, gene flow, and genetic structure at varied by population management zones. Genetic analyses suggested that gene flow followed an isolation-by-distance pattern, and supported male-biased dispersal findings based on demographic data. Several aspects of this project will assist wildlife and land managers in assessing population connectivity and productivity as well as provide a novel approach to augmenting small sage-grouse populations. ​

Associated Publications

Thompson, T. R. 2012. Dispersal ecology of greater sage-grouse in northwestern Colorado: evidence from demographic and genetic methods. Ph.D. Dissertation, University of Idaho, Moscow, USA.

Thompson, T. R., A. D. Apa, K. P. Reese, and K. M. Tadvick. 2015. Captive rearing sage-grouse for augmentation of surrogate wild broods: evidence for success. Journal of Wildlife Management 79:998-1013.

Apa, A. D., K. P. Reese, and T. R. Thompson. In Revision. Greater sage-grouse survival, movements, and recruitment in Colorado. Journal of Wildlife Management XX:XXXX-XXXX.