Rangeland Ecology & Management

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INFLUENCE OF ENVIRONMENTAL CHANGE AND HUMAN ACTIVITIES ON GREATER SAGE-GROUSE LEK COUNTS
Author
Dinkins, Jonathan B.
Beck, Jeffrey L.
Lawson, Kirstie J.
Publisher
Society for Range Management
Publication Year
2018
Body

Hunter harvest of greater sage-grouse (Centrocercus urophasianus; hereafter �sage-grouse�) has been regulated by wildlife agencies during most of the past century. Range-wide population declines of sage-grouse have prompted wildlife agencies to restrict harvest with increasingly more conservative hunting season regulations since the mid-1990�s. Sage-grouse populations are known to oscillate over time, and population growth can be influenced by seasonal weather and habitat disturbance. We compared sage-grouse lek trends from 21 distinct populations in 9 western U.S. states and 2 Canadian provinces from 1995�2013. We stratified 8 harvest histories characterizing these populations into 3 categories (non-hunted, continuously hunted, and hunting season discontinued between 1996�2003) to evaluate the potential impact of harvest on sage-grouse populations. Concomitantly, we assessed the effects of proportion burned, forested and agricultural habitat; winter, spring, and summer precipitation; and human population, road, and oil and gas well densities on lek counts. Density dependent models (Gompertz or Ricker) fit lek trend data best for 7 of the 8 harvest histories. Higher proportions of burnt, forested, and cropland; and greater human population and oil and gas well densities were generally associated with decreasing equilibrium abundance. We found mixed results regarding the effect of hunting regulations on instantaneous growth rate (r). The cessation of harvest from 1996�2001 in approximately half of the largest sage-grouse population was associated with higher r. Continuously harvested sage-grouse populations with permit hunting seasons had higher r during years with higher proportion of area exposed to permitted tag hunting rather than general upland game seasons. However, more liberal hunting regulations were positively associated with higher r in populations continuously harvested under general upland game hunts. Most state and provincial wildlife agencies were adept at monitoring changes in lek trends and subsequently limiting hunting opportunities to prevent hunting sage-grouse facing drastic declines in lek trends.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Reno, NV