10.5061/DRYAD.885HK
Altukhov, Alexey V.
University of Alaska Fairbanks
Andrews, Russel D.
University of Alaska Fairbanks
Alaska SeaLife Center
Calkins, Donald G.
North Pacific Wildlife Consulting LLC, Anchorage, Alaska, USA
Gelatt, Thomas S.
National Oceanic and Atmospheric Administration
Gurarie, Eliezer D.
University of Maryland, College Park
University of Washington
Loughlin, Thomas R.
TRL Wildlife Consulting (NMML retired), Seattle, Washington, USA
Mamaev, Evgeny G.
State Nature Reserve “Komandorsky”, Nikolskoe, Kamchatsky Kray, Russia
Nikulin, Victor S.
Kamchatka Research Institute of Fisheries and Oceanography,
Petropavlovsk-Kamchatsky, Kamchatsky Kray, Russia
Permyakov, Peter A.
V.I. Il'ichev Pacific Oceanological Institute
Ryazanov, Sergey D.
Kamchatka Branch of the Pacific Geographical Institute FEB RAS,
Petropavlovsk-Kamchatsky, Kamchatsky Kray, Russia
Vertyankin, Vladimir V.
Kronotsky Reserve, Yelizovo, Kamchatsky Kray, Russia
Burkanov, Vladimir N.
Kamchatka Branch of the Pacific Geographical Institute FEB RAS,
Petropavlovsk-Kamchatsky, Kamchatsky Kray, Russia
Data from: Age specific survival rates of Steller sea lions at rookeries
with divergent population trends in the Russian Far East
Dryad
dataset
2016
vital rates
western stock
Steller sea lion
Eumetopias jubatus
2016-04-30T00:00:00Z
2016-04-30T00:00:00Z
en
https://doi.org/10.1371/journal.pone.0127292
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
After a dramatic population decline, Steller sea lions have begun to
recover throughout most of their range. However, Steller sea lions in the
Western Aleutians and Commander Islands are continuing to decline.
Comparing survival rates between regions with different population trends
may provide insights into the factors driving the dynamics, but published
data on vital rates have been extremely scarce, especially in regions
where the populations are still declining. Fortunately, an unprecedented
dataset of marked Steller sea lions at rookeries in the Russian Far East
is available, allowing us to determine age and sex specific survival in
sea lions up to 22 years old. We focused on survival rates in three areas
in the Russian range with differing population trends: the Commander
Islands (Medny Island rookery), Eastern Kamchatka (Kozlov Cape rookery)
and the Kuril Islands (four rookeries). Survival rates differed between
these three regions, though not necessarily as predicted by population
trends. Pup survival was higher where the populations were declining
(Medny Island) or not recovering (Kozlov Cape) than in all Kuril Island
rookeries. The lowest adult (> 3 years old) female survival was
found on Medny Island and this may be responsible for the continued
population decline there. However, the highest adult survival was found at
Kozlov Cape, not in the Kuril Islands where the population is increasing,
so we suggest that differences in birth rates might be an important driver
of these divergent population trends. High pup survival on the Commander
Islands and Kamchatka Coast may be a consequence of less frequent (e.g.
biennial) reproduction there, which may permit females that skip birth
years to invest more in their offspring, leading to higher pup survival,
but this hypothesis awaits measurement of birth rates in these areas.
Resight history of Steller sea lions in the Russian Far EastData file
contains annual resight history of Steller sea lions branded as pups
between 1989 and 2008 and resighted between 1996 and 2011 at 6 major
rookeries in the Russian Far East. Detailed information on data structure
provided in read me file.data.csv
Eastern Kamchatka
Commander Islands
Kuril Islands