[MARMAM] paper on scaling pup counts up to abundance estimates for grey seals

Mike Lonergan mel at mcs.st-andrews.ac.uk
Tue Jun 28 00:47:39 PDT 2011


An Approximate Bayesian Method Applied to Estimating the Trajectories of 
Four British Grey Seal (Halichoerus grypus) Populations from Pup Counts.
by  Mike Lonergan, Dave Thompson, Len Thomas and Callan Duck (2011).
Journal of Marine Biology, vol. 2011, Article ID 597424, 7 pages. 
doi:10.1155/2011/597424

Abstract

For British grey seals, as with many pinniped species, population 
monitoring is implemented by aerial surveys of pups at breeding 
colonies.  Scaling pup counts up to population estimates requires 
assumptions about population structure; this is straightforward when 
populations are growing exponentially but not when growth slows, since 
it is unclear whether density dependence affects pup survival or 
fecundity.  We present an approximate Bayesian method for fitting pup 
trajectories, estimating adult population size and investigating 
alternative biological models.  The method is equivalent to fitting a 
density-dependent Leslie matrix model, within a Bayesian framework, but 
with the forms of the density-dependent effects as outputs rather than 
assumptions. It requires fewer assumptions than the state space models 
currently used and produces similar estimates. We discuss the potential 
and limitations of the method and suggest that this approach provides a 
useful tool for at least the preliminary analysis of similar datasets.

JMB is open access, so anyone interested should be able to get the paper 
here:
http://www.hindawi.com/journals/jmb/2011/597424/

Please email me if there are any problems about getting, or with, the paper.

Cheers,

Mike.

-- 
Mike Lonergan
NERC Sea Mammal Research Unit,
Scottish Oceans Institute,
University of St Andrews
________________________________________________________________________________
"The University of St Andrews is a charity registered in Scotland : No SC013532"




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