Habitat use and survival of northern bobwhite (Colinus virginianus) in cropland and rangeland ecosystems during the hunting season

摘要

Many researchers and managers believe that land-use practices are most responsible for declines in northern bobwhite (Colinus virginianus) populations. Additionally, researchers have suggested that the amount of available escape cover in a landscape could alter winter survival of bobwhites. A comparative study of winter bobwhite ecology was conducted on rangeland and cropland ecosystems in east-central Kansas (11 November - 31 January 1993-1996). We considered woody cover type on our study areas to be an escape cover for quail. We used radiotelemetry to investigate survival, movement, and cover-type selection. Over the 3-year period, we monitored 91 individuals on a cropland study area (CSA) and 66 birds on a rangeland study area (RSA). Survival was higher on the CSA (0.46) than on the RSA (0.27) (P = 0.03); the difference was due to increased harvest mortality on the RSA (P = 0.04). Mean daily covey movement was higher on the RSA than on the CSA (P < 0.01). Comparing cover-type selection between study areas, it was found that bobwhites selected cropland more on the RSA than on the CSA (P < 0.01). On the RSA, increased daily movement correlated with decreased selection for woody cover and increased selection for cropland (P < 0.02). On the CSA, increased woody-cover selection decreased natural predation (P = 0.03). On the RSA, decreased movement, increased woody cover, and decreased pasture selection reduced natural predation (P < 0.05). However, increased woody-cover selection increased harvest mortality (P < 0.01). Consequently, we consider the selection for woody cover to be an important variable in bobwhite survival on the RSA. It is suggested that landowners on rangelands could reduce natural mortality by taking advantage of programs available from federal and state governments and nongovernmental organizations, to increase woody cover for bobwhites. [References: 33]