Steller sea lion (Eumetopias jubatus) pups (n = 366) were hot-branded at Lowrie Island, Southeast Alaska, USA, in June 2001 and 2002 for vital-rates studies. To assess potential mortality following branding, we estimated weekly survival to 12 weeks postbranding using mark–recapture models. Survival estimates ranged from 0.984/week to 0.988/week, or 0.868 over the 12-week period; varied little with sex, year, and capture area; and were higher for larger than smaller male pups and unexpectedly lower for larger than smaller female pups. Inclusion of resights at 1–3 years of age prevented a −4.5% bias in cumulative survival to 12 weeks postbranding by accounting for pups that survived but permanently emigrated from Lowrie Island during the 12-week survey. Data from double-marked pups (i.e., branded and flipper-tagged) indicated the low brand-misreading probability of 3.1% did not bias survival estimates. Assuming survival differences between the first 2 weeks postbranding and later weeks were due entirely to the branding event, potential postbranding mortality of branded pups attributable to the branding event was 0.5–0.7%, or one pup for every 200 marked. Weekly survival of branded pups was nearly identical to estimates from a control group of undisturbed, unbranded pups born to 10–11-year-old branded adult females in 2005 (0.987–0.988/week) and similar to pup survival estimates from other otariid studies. Available data did not indicate substantial mortality to 12 weeks postbranding resulting from the branding disturbance, suggesting branding of Steller sea lion pups can be used effectively for investigations of population declines without significantly affecting population health or study goals.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 73 • No. 7