Re‐Evaluation of Yellowstone Grizzly Bear Population Dynamics not Supported by Empirical Data: Response to Doak & Cutler

Conservation Letters

Frank T. van Manen¹  Michael R. Ebinger⁴  Mark A. Haroldson¹  Richard B. Harris⁴  Megan D. Higgs³  Steve Cherry³  Gary C. White² 

[1]U. S. Geological Survey, Northern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team, Bozeman, MT, USA

[2]Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, USA

[3]Department of Mathematical Sciences, Montana State University, Bozeman, MT, USA

[4]College of Forestry and Conservation, University of Montana, Missoula, MT, USA

关键词: Chao estimator;    demographic projection;    Doak & Cutler;    grizzly bears;    population trend;    rebuttal;    scientific review;    Ursus arctos;    Yellowstone;   

DOI  :  10.1111/conl.12095

来源: Wiley

【 摘 要 】

Abstract

Doak and Cutler critiqued methods used by the Interagency Grizzly Bear Study Team (IGBST) to estimate grizzly bear population size and trend in the Greater Yellowstone Ecosystem. Here, we focus on the premise, implementation, and interpretation of simulations they used to support their arguments. They argued that population increases documented by IGBST based on females with cubs-of-the-year were an artifact of increased search effort. However, we demonstrate their simulations were neither reflective of the true observation process nor did their results provide statistical support for their conclusion. They further argued that survival and reproductive senescence should be incorporated into population projections, but we demonstrate their choice of extreme mortality risk beyond age 20 and incompatible baseline fecundity led to erroneous conclusions. The conclusions of Doak and Cutler are unsubstantiated when placed within the context of a thorough understanding of the data, study system, and previous research findings and publications.

【 授权许可】

Unknown   
©2014 Wiley Periodicals, Inc.