[MARMAM] New publication: Survival probabilities and movements of harbor seals in central California (Suzanne C. Manugian)

Suzanne Manugian suzannemanugian at gmail.com
Wed Aug 24 10:02:47 PDT 2016

Hi MARMAM-ers.

My co-authors and I are pleased to announce the following paper, made
available last week in Marine Mammal Science (early view):
Manugian, S. C., Greig, D., Lee, D., Becker, B. H., Allen, S., Lowry, M. S.
and Harvey, J. T. (2016) Survival probabilities and movements of harbor
seals in central California. Marine Mammal Science. doi:10.1111/mms.12350

Abstract: Harbor seal numbers and population trajectories differ by
location in central California. Within San Francisco Bay (SFB) counts have
been relatively stable since the 1972 Marine Mammal Protection Act, but in
coastal areas like Tomales Bay (TB), counts increased before stabilizing in
the 1990s. Emigration, poor survival, and environmental effects have been
hypothesized as contributors to differences between trajectories; however,
basic demographic data were not available to evaluate these hypotheses. We
monitored 32 radio-tagged adult females (SFB *n* = 17, TB *n* = 15) for 20
mo (2011–2013), and estimated survival, resight, and movement probabilities
using mark-resight analyses and multistate mark-resight models. Annual
survival probability for both sites was 0.90 (95% CI = 0.18–0.99). Six
seals were observed moving between locations resulting in an estimated
probability of 0.042 (95% CI = 0.023–0.076) per month equal movement
between sites. Resight probability was less in SFB relative to TB, likely
due to differential haul-out access, area surveyed, visibility, and resight
effort. Because of wide confidence intervals and low precision of these
first estimates of adult female harbor seal survival in California, this
demographic must be further examined to dismiss its contribution to
differing population trajectories. Using aerial survey data, we estimated
950 harbor seals in SFB (95% CI = 715–1,184) confirming numbers are still

Full text is available online here: http://onlinelibrary.
Please contact me with any inquiries or requests for PDF version:
suzannemanugian at gmail.com

  ~ Suzanne Manugian + co-authors

Suzanne Manugian, M.Sc.
   858.546.7141 (desk
   [ LinkedIn Profile ]
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.uvic.ca/pipermail/marmam/attachments/20160824/5ec33af0/attachment.html>

More information about the MARMAM mailing list