Steller sea lion

Publication Title: 

Age-specific vibrissae growth rates: A tool for determining the timing of ecologically important events in Steller sea lions

Authors: 
Rea, L.D., A.M. Christ, A.B. Hayden, V.K. Stegall, S.D. Farley, C.A. Stricker, J.E. Mellish, J.M. Maniscalco, J.N. Waite, V.N. Burkanov, and K.W. Pitcher
Publication Date: 
2015
Parent Publication Title: 
Marine Mammal Science
Publication Type: 
Archive number: 
2015/0038 FORT
States: 

Pub Abstract: 

Steller sea lions (SSL; Eumetopias jubatus) grow their vibrissae continually, providing a multiyear record suitable for ecological and physiological studies based on stable isotopes. An accurate age-specific vibrissae growth rate is essential for registering a chronology along the length of the record, and for interpreting the timing of ecologically important events. We utilized four methods to estimate the growth rate of vibrissae in fetal, rookery pup, young-of-the-year (YOY), yearling, subadult, and adult SSL. The majority of vibrissae were collected from SSL live-captured in Alaska and Russia between 2000 and 2013 (n = 1,115), however, vibrissae were also collected from six adult SSL found dead on haul-outs and rookeries during field excursions to increase the sample size of this underrepresented age group. Growth rates of vibrissae were generally slower in adult (0.44 +/- 0.15 cm/mo) and subadult (0.61 +/- 0.10 cm/mo) SSL than in YOY (0.87 +/- 0.28 cm/mo) and fetal (0.73 +/- 0.05 cm/mo) animals, but there was high individual variability in these growth rates within each age group. Some variability in vibrissae growth rates was attributed to the somatic growth rate of YOY sea lions between capture events (P = 0.014, r2 = 0.206, n = 29).

Publication Title: 

Stable isotope values in pup vibrissae reveal geographic variation in diets of gestating Steller sea lions Eumetopias jubatus

Authors: 
Scherer, R.D., A.C. Doll, L.D. Rea, A.M. Christ, C.A. Stricker, B. Witteveen, T.C. Kline, C.M. Kurle, and M.B. Wunder
Publication Date: 
2015
Parent Publication Title: 
Marine Ecology Progress Series
Publication Type: 
Archive number: 
2015/0024 FORT
States: 

Pub Abstract: