scholarly journals A Protocol for Better Design, Application, and Communication of Population Viability Analyses

2013 ◽  
Vol 27 (4) ◽  
pp. 644-656 ◽  
Author(s):  
GUY PE'ER ◽  
YIANNIS G. MATSINOS ◽  
KARIN JOHST ◽  
KAMILA W. FRANZ ◽  
CAMILLE TURLURE ◽  
...  
Author(s):  
Louis W. Botsford ◽  
J. Wilson White ◽  
Alan Hastings

This chapter describes how models can aid in managing populations to prevent extinction, given uncertainty about their state. From previous chapters, it is clear that avoiding extinction requires keeping both abundance and the replacement rate high. However, for both, the question remains, how high? The question of how high abundance should be to achieve a certain risk is addressed by existing population viability analyses (PVA). By contrast, the problem of maintaining high replacement has received little attention. This chapter describes how uncertainty in population parameters and the frequency spectrum of the environment both affect estimates of the probability of extinction, including examples of PVAs that pay greater attention to those complications. Additionally, an example is provided of tracking both abundance and replacement to avoid extinction for many different populations of a single taxon, Pacific salmon. Finally, the role of portfolio effects (diversity in variance among populations) is explored.


2018 ◽  
Vol 34 (6) ◽  
pp. 1285-1292 ◽  
Author(s):  
Janice L. Albers ◽  
Mark L. Wildhaber ◽  
Nicholas S. Green

2018 ◽  
Vol 75 (12) ◽  
pp. 2149-2158 ◽  
Author(s):  
Andrew R. Murdoch ◽  
Chad J. Herring ◽  
Charles H. Frady ◽  
Kevin See ◽  
Chris E. Jordan

This study examined how a suite of habitat and environmental variables relate to the ability of a stream surveyor to identify (observer efficiency) and distinguish (observer accuracy) steelhead (Oncorhynchus mykiss) redds from other stream features. Two existing spawning survey protocols that included one or two redd observers were used to develop models to estimate redd observer error. In most cases, steelhead redd abundances using raw redd counts were underestimated. Mean annual rates of observer efficiency ranged from 0.44 to 0.57, and observer accuracy ranged from 0.67 to 0.83. Regardless of the observer error model used, adjusted annual redd abundance estimates were generally unbiased (range 1.6–0.6 redds). A Gaussian area-under-the-curve methodology that incorporates redd count data and observer error rates was used to generate unbiased estimates of steelhead redd abundance in the Wenatchee (170 redds, coefficient of variation (CV) = 44%) and Methow (106 redds, CV = 41%) rivers. Unbiased estimates of redd abundance will help inform new population viability analyses to better prioritize those populations with the greatest conservation need.


2001 ◽  
Vol 97 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Andrew P. Chapman ◽  
Barry W. Brook ◽  
Tim H. Clutton-Brock ◽  
Bryan T. Grenfell ◽  
Richard Frankham

Author(s):  
H. Carneiro ◽  
S.R. Paiva ◽  
M. Ledur ◽  
E.A.P. Figueiredo ◽  
V.H. Grings ◽  
...  

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