Disturbance and the survival of female ring-necked pheasants in Illinois

There is little knowledge of how disturbances affect the behavior and survival of pheasants in agricultural landscapes of the Midwest. Thus, we studied the survival of 81 female ring-necked pheasants (Phasianus colchicus) in Ford County, eastcentral Illinois, from 1989-94. Among the most intensively cropped regions of North America, the study area averaged 93% row crops (corn and soybeans, in equal proportion). We monitored the numbers of extended movements by hens associated with farm operations, hunting, weather, and other causes. The average number of extended movements observed per bird (3.5 +/- 0.4) was not different for adults and juveniles. Using the Kaplan-Meier product-limit estimator of survival, the longevity of hens with more than the median number of extended movements was greater (330 +/- 37 days) than hens with less than the median number of extended movements (115 +/- 15 days). Hens exhibiting disturbance-avoidance behavior associated with extended movements coped relatively well with hazards, except during nesting. Our findings underscore the importance of movement as a survival mechanism in a hazardous landscape with marginally suitable habitat.