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Journal Article

Mark‐recapture modeling accounting for state uncertainty provides concurrent estimates of survival and fecundity in a protected harbor seal population

Line S. Cordes; Paul M. Thompson
Marine Mammal Science · Vol. 30, Issue 2 · pp. 691-705 · 2014

Abstract

Harbor seal breeding behavior and habitats constrain opportunities for individual‐based studies, and no current estimates of both survival and fecundity exist for any of the populations studied worldwide. As a result, the drivers underlying the variable trends in abundance exhibited by harbor seal populations around the world remain uncertain. We developed an individual‐based study of harbor seals in northeast Scotland, whereby data were collected during daily photo‐identification surveys throughout the pupping seasons between 2006 and 2011. However, a consequence of observing seals remotely meant that information on sex, maturity‐stage, or breeding status was not always available. To provide unbiased estimates of survival rates we conditioned initial release of individuals on the first time sex was known to estimate sex‐specific survival rates, while a robust design multistate model accounting for uncertainty in breeding status was used to estimate reproductive rate of multiparous and ≥3‐yr‐old females. Survival rates were estimated at 0.95 (95% CI = 0.91–0.97) for females and 0.92 (0.83–0.96) for males, while reproductive rate was estimated at 0.89 (0.75–0.95) for multiparous and 0.69 (0.64–0.74) for ≥3‐yr‐old females. Stage‐based population modeling indicated that this population should be recovering, even under the current shooting quotas implemented by the recent management plan.

Bibliographic Information

JournalMarine Mammal Science
PublisherWiley
Publication Date2014-04-01
Publication Year2014
Volume30
Issue2
Pages691-705
Document TypeJournal Article
Print ISSN0824-0469
eISSN1748-7692
DOI10.1111/mms.12070
SubjectMarine Biology

Access Information

NARA Access Coverage1997-01-01~Current
Journal Homepagehttps://onlinelibrary.wiley.com/loi/17487692
Publisher PageOpen Publisher Page
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