Are Wintering Areas Shifting North? Learning from Lesser Snow Geese Banded in Southwest Louisiana

作者：Jonsson Jon Einar^*; Afton Alan D

来源：Southeastern Naturalist, 2015, 14(2): 293-307.

DOI：10.1656/058.014.0212

Several avian species have shifted their wintering or staging areas north in response to advancing onset of spring. Our objectives were to determine whether (1) the latitudinal distribution of recoveries changed for Chen caerulescens caerulescens (Lesser Snow Goose; hereafter Snow Goose) banded in southwest Louisiana, and (2) annual proportions of recoveries within Louisiana relative to other locations in the midcontinent flyways were related to local weather or Snow Goose population estimates for southwest Louisiana. We collated and analyzed population indices from the annual midwinter waterfowl survey for the period 2002-2013 with band recovery and local weather data. Latitudes of recovery shifted north during the period, and the increases were independent of season (fall, midwinter, and late winter/spring migration). Annual proportions of recoveries within Louisiana (all from southwest Louisiana), were lower during wet winters when the largest numbers of Snow Geese were counted in southwest Louisiana. We concluded that Snow Geese banded in our study area have shifted their wintering range northwards. Furthermore, the probability of recovery in Louisiana was somewhat dependent on Snow Goose numbers present, apparently because hunters shoot proportionally fewer banded birds during years with more Snow Geese, which in turn were related to high amounts of precipitation in the area.

• 出版日期2015-6