Greater Sage-Grouse Population Dynamics and Probability of Persistence

We updated our earlier comprehensive analysis of Greater Sage-Grouse (Centrocercus urophasianus) population dynamics and probability of persistence from 1965 to 2007 throughout the species range by accumulating and analyzing additional counts of males from 2008 to 2013. A total of 89,749 counts were conducted by biologists and volunteers at 10,060 leks from 1965 through 2013 in 11 states occupied by Greater Sage-Grouse. In spite of survey effort increasing substantially (12.6%) between 2007 and 2013, the reconstructed estimate for minimum number of breeding males in the population, using standard approximations for missing values from Colorado, fell by 56% from109,990 breeding males in 2007 to 48,641 breeding males in 2013. The best model of annual rates of change of populations estimated across the Sage-Grouse Management Zones was a stochastic density dependent Gompertz model with 1-year time lags and declining carrying capacities through time. Weighted mean estimates of carrying capacity for the minimum number of males counted at leks for the entire range-wide distribution, excepting Colorado, were 40,505 (SE 6,444) in 2013 declining to 19,517 (SE 3,269) in 30 years and 8,154 (SE 1,704) in 100 years. Starting with the estimated abundance of males counted at leks in 2007 a simple effort to evaluate the validity of future forecasts of abundance was conducted by forecasting abundance in 2013 from Gompertz density dependent models with 1year time lag and declining carrying capacity models of 6 of the 7 management zone populations. Estimated mean abundance in 2013 predicted 97.8% of the variation in true abundance in management zones. Concerted efforts across both public and private land ownerships that are intended to benefit Greater Sage-Grouse show little current evidence of success but more will be required to stabilize these declining populations and ensure their continued persistence in the face of ongoing development and habitat modification in the broad sagebrush region of western North America. _____________________________________________________________________________ 1 Emeritus Professor, University of Idaho, Moscow; 2 Washington State University, Vancouver; 3 Texas AM 4 Retired Research Scientist, Idaho Department of Fish and Game, Blackfoot

[1]  C. Krebs,et al.  What Drives the 10-year Cycle of Snowshoe Hares? , 2001 .

[2]  Anthony D. Apa,et al.  DISTRIBUTION OF SAGE-GROUSE IN NORTH AMERICA , 2004 .

[3]  L. Burnett.  The Sage Grouse, Centrocercus urophasianus , 1905 .

[4]  David R. Anderson,et al.  Model selection and multimodel inference : a practical information-theoretic approach , 2003 .

[5]  R Core Team,et al.  R: A language and environment for statistical computing. , 2014 .

[6]  D. Naugle,et al.  Greater Sage-Grouse Winter Habitat Selection and Energy Development , 2008 .

[7]  S. Stiver.  Greater Sage-grouse Comprehensive Conservation Strategy , 2006 .

[8]  Cameron L. Aldridge,et al.  West Nile virus and sage-grouse: What more have we learned? , 2005 .

[9]  L. Keith.  Role of food in hare population cycles , 1983 .

[10]  C. Aldridge.  DO SAGE-GROUSE HAVE A FUTURE IN CANADA ? POPULATION DYNAMICS AND MANAGEMENT SUGGESTIONS , 2001 .

[11]  C. Bradshaw,et al.  Strength of evidence for density dependence in abundance time series of 1198 species. , 2006, Ecology.

[12]  Brian Dennis,et al.  DENSITY DEPENDENCE IN TIME SERIES OBSERVATIONS OF NATURAL POPULATIONS: ESTIMATION AND TESTING' , 1994 .

[13]  P. Rothery,et al.  WEATHER AND SYNCHRONY IN 10‐YEAR POPULATION CYCLES OF ROCK PTARMIGAN AND RED GROUSE IN SCOTLAND , 2000 .

[14]  J. Connelly,et al.  Distribution, movements and habitats of sage grouse Centrocercus urophasianus on the Upper Snake River Plain of Idaho: changes from the 1950s to the 1990s , 2000, Wildlife Biology.

[15]  M. Holloran,et al.  GREATER SAGE-GROUSE (Centrocercus urophasianus) POPULATION RESPONSE TO NATURAL GAS FIELD DEVELOPMENT IN WESTERN WYOMING , 2005 .

[16]  Sharon Baruch-Mordo,et al.  Saving sage-grouse from the trees: A proactive solution to reducing a key threat to a candidate species , 2013 .

[17]  C. Braun.  SAGE GROUSE DECLINES IN WESTERN NORTH AMERICA: WHAT ARE THE PROBLEMS? , 1998 .

[18]  R. Lande,et al.  Estimating Density Dependence from Population Time Series Using Demographic Theory and Life‐History Data , 2002, The American Naturalist.

[19]  A. Pocewicz,et al.  Measuring the Effectiveness of Conservation: A Novel Framework to Quantify the Benefits of Sage-Grouse Conservation Policy and Easements in Wyoming , 2013, PloS one.

[20]  U. Fish.  Endangered and threatened wildlife and plants , 1987 .

[21]  D. Naugle,et al.  Greater Sage-Grouse Population Response to Energy Development and Habitat Loss , 2007 .

[22]  Brian Dennis,et al.  Estimation of Growth and Extinction Parameters for Endangered Species , 1991 .

[23]  S. Lele,et al.  ESTIMATING DENSITY DEPENDENCE, PROCESS NOISE, AND OBSERVATION ERROR , 2006 .

[24]  H. Akaike,et al.  Information Theory and an Extension of the Maximum Likelihood Principle , 1973 .

[25]  J. Connelly,et al.  Greater Sage-Grouse and Sagebrush: An Introduction to the Landscape , 2011 .

[26]  M. Holloran,et al.  SPATIAL DISTRIBUTION OF GREATER SAGE-GROUSE NESTS IN RELATIVELY CONTIGUOUS SAGEBRUSH HABITATS , 2005 .

[27]  Bernd Blasius,et al.  Complex dynamics and phase synchronization in spatially extended ecological systems , 1999, Nature.

[28]  Brian Dennis,et al.  COMPLEX POPULATION DYNAMICS IN THE REAL WORLD: MODELING THE INFLUENCE OF TIME-VARYING PARAMETERS AND TIME LAGS , 1998 .

[29]  K. Burnham,et al.  Model selection: An integral part of inference , 1997 .

[30]  Cameron L. Aldridge,et al.  West Nile virus: pending crisis for greater sage-grouse , 2004 .

[31]  J. Connelly,et al.  Long-term changes in sage grouse Centrocercus urophasianus populations in western North America , 1997, Wildlife Biology.

[32]  Michael J. Wisdom,et al.  Characteristics of Sagebrush Habitats and Limitations to Long-Term Conservation , 2011 .

[33]  Michael A. Schroeder,et al.  Conservation assessment of greater sage-grouse and sagebrush habitats / , 2004 .

[34]  Jeffrey L. Beck,et al.  Consequences of Treating Wyoming Big Sagebrush to Enhance Wildlife Habitats , 2012 .

[35]  Steven E. Hanser,et al.  Connecting pattern and process in greater sage-grouse populations and sagebrush landscapes , 2011 .

[36]  R. Patterson,et al.  The Sage Grouse in Wyoming , 1953 .

[37]  E. Michael.  THRESHOLDS FOR SURVIVAL: MAINTAINING FITNESS AND EVOLUTIONARY POTENTIAL , 2008 .

[38]  D. Naugle,et al.  West Nile Virus and Greater Sage-Grouse: Estimating Infection Rate in a Wild Bird Population , 2007, Avian diseases.