Population size of 2,150 estimated using mark-recapture in 2007. Subpopulation likely increased over the last 30 years. Empirical birth and death rates suggest population is now declining.
Status table outtake
|
Aerial survey / Mark-recapture analysis |
Additional / Alternative Analysis |
|||||||||||
| Number (year of estimate) |
±2 SE or 95% CI |
Number (year of estimate) |
±2 SE or min-max range |
Sim | TEK | Historical annual removals (5 yr mean) | Potential maximum annual removals | Status | Current trend | Estimated risk of future decline | ||
| 2142 (2007) | 1811-2534 | 60 | 66 | Not reduced | Declining | Very high | ||||||
Table comment: New estimates of natural survival and current harvest suggest the population may begin to decline. Scientific and local knowledge suggest the population has significantly increased in the past.
Based on the recapture or harvest of previously tagged animals and of adult females with satellite collars, the Davis Strait (DS) polar bear subpopulation occurs in the Labrador Sea, eastern Hudson Strait, Davis Strait south of Cape Dyer, and along an as yet undetermined portion of south-west Greenland (Stirling et al. 1980, Stirling and Killian 1980, Taylor and Lee 1995, Taylor et al. 2001a). A genetic study of polar bears (Paetkau et al. 1999) indicated significant differences between bears from southern DS and both Baffin Bay and Foxe Basin; Crompton et al. (2008) found that individuals from northern portions of DS and those from Foxe Basin share a high degree of ancestry. The initial subpopulation estimate of 900 bears for DS (Stirling et al. 1980, Stirling and Killian 1980) was based on a subjective correction from the original mark-recapture calculation of 726 bears, which was felt to be too low because of possible bias in the sampling. In 1993, the estimate was again increased to 1,400 bears and to 1,650 in 2005. These increases were to account for the bias as a result of springtime sampling, the fact that the existing harvest appeared to be sustainable and not having negative effects on the age structure, and TEK which suggested that more bears were being seen over the last 20 years. The most recent inventory of this subpopulation was completed in 2007; the new subpopulation estimate is 2,142 (95% log-normal CI, 1811 – 2534). Using new recruitment and natural survival estimates (Tables 3, 4), the 10-year mean un-harvested geometric population growth rate is 0.98 ± 0.001 (Peacock 2009; see Research in Canada, this volume). DS is currently declining based on survival rates calculated from data collected up to the conclusion of the mark-recapture study in 2007. Ecological covariates associated with survival suggest that the decline may be as a combined result of short-term and local density dependence, stabilization of harp seal (Pagophilus groenlandicus) numbers and declining ice conditions.