Avian Conservation and Ecology (Dec 2017)
Northern Pintail (Anas acuta) survival, recovery, and harvest rates derived from 55 years of banding in Prairie Canada, 1960-2014
Abstract
Northern Pintail (Anas acuta; hereafter pintail) experienced a significant population decline in North America in the 1980s but did not rebound to the previous population level the way that other prairie dabbling duck species (Anas spp.) did once habitat conditions improved. Although the population decline occurred throughout the breeding range of pintails, the decline was most pronounced and sustained in Prairie Canada, i.e., southern Alberta and Saskatchewan. Thus, we estimated and examined annual survival, recovery, and harvest rates of pintails banded in Prairie Canada from 1960-2014. Annual survival rates varied by sex but were relatively high compared to those of other dabbling duck species and increased slightly over the study period to end at 0.64 ± 0.13 (SE) and 0.74 ± 0.10 for females and males, respectively. Recovery and harvest rates varied over time but generally declined in the 1980s and increased from the early 1990s until the end of the study period. There was no clear evidence that hunting bag limit restrictions affected annual survival, recovery, or harvest rates. In addition, we could find no compelling evidence that harvest mortality was substantially additive to nonharvest mortality for pintails. However, we could not definitively ascertain the effects of the restrictions, and we suggest that a trial basis of liberalized hunting bag limits would do much to improve the understanding of harvest and population dynamics of pintails and pose little risk to the population. Based on our results, we believe that measures other than harvest restrictions will likely have to be taken to elevate the pintail population to the North American Waterfowl Management Plan objective.
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