Survival of adult Steller sea lions in Alaska: senescence, annual variation and covariation with male reproductive success

Population dynamics of long-lived vertebrates depend critically on adult survival, yet factors affecting survival and covariation between survival and other vital rates in adults remain poorly examined for many taxonomic groups of long-lived mammals (e.g. actuarial senescence has been examined for only 9 of 34 extant pinniped species using longitudinal data). We used mark-recapture models and data from 2,795 Steller sea lion (Eumetopias jubatus) pups individually-marked at 4 of 5 rookeries in southeastern Alaska (SEAK) and resighted for 22 years to examine senescence, annual variability, and covariation among life-history traits in this long-lived, sexually-dimorphic pinniped. Sexes differed in age of onset (~16–17 and ~8-9 years for females and males, respectively), but not rate (-0.047 and -0.046/year of age for females and males) of senescence. Survival of adult males from northern SEAK had greatest annual variability (~±0.30 among years), whereas survival of adult females ranged ~...