DOI: 10.5061/dryad.h44j0zpjb
title: Brown bear population vital rates

description: Identifying mechanisms of population change is fundamental for conserving
 small and declining populations and determining effective management
 strategies. Few studies, however, have measured the demographic components
 of population change for small populations of mammals (&lt; 50
 individuals). We estimated vital rates and trends in two adjacent but
 genetically distinct, threatened brown bear (Ursus arctos) populations in
 British Columbia, Canada, following the cessation of hunting. One
 population had approximately 45 resident bears but had some genetic and
 geographic connectivity to neighbouring populations, while the other
 population had &lt; 25 individuals and was isolated. We estimated
 population-specific vital rates by monitoring survival and reproduction of
 telemetered female bears and their dependent offspring from 2005 to 2018.
 In the larger, connected population, independent female survival was 1.00
 (95% CI: 0.96-1.00) and the survival of cubs in their first year was 0.85
 (95% CI: 0.62-0.95). In the smaller, isolated population, independent
 female survival was 0.81 (95% CI: 0.64-0.93) and first-year cub survival
 was 0.33 (95% CI: 0.11-0.67). Reproductive rates did not differ between
 populations. The large differences in age-specific survival estimates
 resulted in a projected population increase in the larger population (λ =
 1.09; 95% CI: 1.04-1.13) and population decrease in the smaller population
 (λ = 0.84; 95% CI: 0.72-0.95). Low female survival in the smaller
 population was the result of both continued human-caused mortality and an
 unusually high rate of natural mortality. Low cub survival may have been
 due to inbreeding and the loss of genetic diversity common in small
 populations, or to limited resources. In a systematic literature review,
 we compared our population trend estimates with those reported for other
 small populations (&lt; 300 individuals) of brown bears. Results
 suggest that once brown bear populations become small and isolated,
 populations rarely increase and, even with intensive management, recovery
 remains challenging.
description: ch_survival.txt: This dataset is the monthly survival and
 monitoring data of independent (not with mother) female grizzly bears. It
 is formatted for processing in Rmark with monthly intervals for 7 months
 and one 5 month interval for winter. Each year from 2005-2018.
 transition_reproductive_state.txt: Transitions between
 reproductive state for collared adult female grizzly bears in two adjacent
 populations. AA -alone to alone; AC - alone to with cubs; CY- with cubs to
 with yearlings; CA - with cubs to alone; Y-A yearling to alone; Y-T
 yearling to with two-year-old offspring; T-A with two-year-old offspring
 to alone or older offspring.  coy_survial.txt:
 Dependent offspring survival in the first year of life and litter
 membership by population. yearling_survival.txt:
 Dependent offspring survival in the second year of life by
 population. primiparity.txt: Monitoring and
 reproduction of primiparous female grizzly bears by population. For each
 age, data show whether they had their first litter or not and whether they
 were removed from the sample by mortality or because their reproductive
 fate was unknown (i.e. radio-collar dropped).
 interbirth_interval.txt: Interbirth interval of parous female
 grizzly bears by population. For each year following a reproductive event
 whether another reproductive event was observed until the female
 reproduced or they were removed from the sample by mortality or because
 their reproductive fate was unknown (i.e. radio-collar dropped).
description: The data is complete.