[MARMAM] New publication on mark-recapture modelling when there is heterogeneity linked to reproductive state: application to southern right whales

Emma Carroll ecar026 at aucklanduni.ac.nz
Thu Apr 18 15:15:33 PDT 2013

Dear Colleagues,

We are pleased to announced the publication of the following paper

Carroll, Emma, Simon Childerhouse, Rachel M. Fewster, Nathalie J.
Patenaude, Debbie Steel, Glenn Dunshea, Laura Boren, and C. Scott
Baker. In press. Accounting for female reproductive cycles in a
superpopulation capture-recapture framework. Ecological Applications.

Accounting for female reproductive cycles in a superpopulation
capture-recapture framework

Emma Carroll 1,*, Simon Childerhouse 2, Rachel M. Fewster 3, Nathalie
J. Patenaude 4, Debbie Steel 5, Glenn Dunshea 6, Laura Boren 7, and C.
Scott Baker 8

Superpopulation capture-recapture models are useful for estimating the
abundance of long-lived, migratory species as they are able to account
for the fluid nature of annual residency at migratory destinations.
Here we extend the superpopulation POPAN model to explicitly account
for heterogeneity in capture probability linked to reproductive cycles
(POPAN-τ). This extension has potential application to a range of
species that have temporally variable life stages (e.g. non-annual
breeders such as albatrosses and baleen whales) and results in a
significant reduction in bias over the standard model. We demonstrate
the utility of this model in simultaneously estimating abundance and
annual population growth rate (λ) in the New Zealand (NZ) southern
right whale from 1995-2009. DNA profiles were constructed for the
individual identification of more than 700 whales, sampled during two
sets of winter expeditions in 1995-1998 and 2006-2009. Due to
differences in recapture rates between sexes, only sex-specific models
were considered. The POPAN-τ models, which explicitly account for a
decrease in capture probability in non-calving years, fit the female
dataset significantly better than standard superpopulation models
(ΔAIC>25). The best POPAN-τ model (AIC) gave a superpopulation
estimate of 1162 females for 1995-2009 (95% CL 921, 1467) and an
estimated annual increase of 5% (95% CL -2%, 13%). The best model
(AIC) gave a superpopulation estimate of 1007 males (95% CL 794, 1276)
and an estimated annual increase of 7% (95% CL 5%, 9%) for 1995-2009.
Combined, the total superpopulation estimate for 1995-2009 was 2169
whales (95% CL 1836, 2563). Simulations suggest that failure to
account for the effect of reproductive status on the capture
probability would result in a substantial positive bias (+19%) in
female abundance estimates.

Read More: http://www.esajournals.org/doi/abs/10.1890/12-1657.1

Emma Carroll PhD
Postdoctoral Researcher
Molecular Ecology and Evolution | School of Biological Sciences
University of Auckland | phone 64 9 3737599 x 71762

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