Re-evaluation of Yellowstone grizzly bear population dynamics not supported by empirical data: response to Doak & Cutler

Conservation Letters
By: , and 

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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.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Re-evaluation of Yellowstone grizzly bear population dynamics not supported by empirical data: response to Doak & Cutler
Series title Conservation Letters
DOI 10.1111/conl.12095
Volume 7
Issue 3
Year Published 2014
Language English
Publisher Society for Conservation Biology
Contributing office(s) Northern Rocky Mountain Science Center
Description 9 p.
First page 323
Last page 331
Online Only (Y/N) N
Additional Online Files (Y/N) N