Using supplemental food and its influence on survival of northern bobwhite (Colinus virginianus)

摘要

The composition of feed in the crops of 783 Northern bobwhites (Colinus virginianus) which were killed in hunts conducted during 1992-96 were examined. The bobwhites were from 2 284-hectare areas in Oklahoma, USA, one of which contained 55-gallon barrels of sorghum as a supplementary feeding sources. Wheat, milo and millet were placed on both areas as part of the normal management routine. In addition, bobwhites were trapped, tagged and released to assess winter survival. Crops of bobwhites harvested from areas with supplemental feeders contained 28.2% supplemental food compared with 5.5% (P<0.001) for those from areas without supplemental feeders. Winter climate was not a significant predictor of the proportional use of supplemental feeders. Rates of winter survival were greater on areas with supplemental feeders compared with non-supplemented areas in winters 1992-1993 (P=0.001) and 1993-1994 (P=0.002), but in 1994-1995, rates were greater on non-supplemented areas (P=0.032). Cause-specific mortality rates indicated that supplemental feeders did not predispose bobwhites to hunter harvest or predation. It is concluded that bobwhites can gain nutritional benefits from supplemental feeders during times of severe winter stress.