Data from: Integrated population modeling provides the first empirical estimates of vital rates and abundance for polar bears in the Chukchi Sea

Large carnivores are imperiled globally, and characteristics making them
vulnerable to extinction (e.g., low densities and expansive ranges) also
make it difficult to estimate demographic parameters needed for
management. Here we develop an integrated population model to analyze
capture-recapture, radiotelemetry, and count data for the Chukchi Sea
subpopulation of polar bears (Ursus maritimus), 2008–2016. Our model
addressed several challenges in capture-recapture studies for polar bears
by including a multievent structure reflecting location and life history
states, while accommodating state uncertainty. Female breeding probability
was 0.83 (95% credible interval [CRI] = 0.71–0.90), with litter sizes of
2.18 (95% CRI = 1.71–2.82) for age-zero and 1.61 (95% CRI = 1.46–1.80) for
age-one cubs. Total adult survival was 0.90 (95% CRI = 0.86–0.92) for
females and 0.89 (95% CRI = 0.83–0.93) for males. Spring on-ice densities
west of Alaska were 0.0030 bears/km2 (95% CRI = 0.0016–0.0060), similar to
1980s-era density estimates although methodological differences complicate
comparison. Abundance of the Chukchi Sea subpopulation, derived by
extrapolating density from the study area using a spatially-explicit
habitat metric, was 2,937 bears (95% CRI = 1,552–5,944). Our findings are
consistent with other lines of evidence suggesting the Chukchi Sea
subpopulation has been productive in recent years, although it is
uncertain how long this will continue given sea-ice loss due to climate
change.