Declining Survival of Ring-Necked Pheasant Chicks in Illinois during the Late 1900s

Abstract

Listen

Translate article

Previous studies indicated that survival of ring-necked pheasant (Phasianus colchicus) chicks during the first 6 weeks of life declined from the early 1950s through early 1980s in Illinois with the expansion of corn and soybean production and associated clean farming practices. From the early 1980s through mid-1990s intensive row-crop production was moderated by farm programs such as the Conservation Reserve Program (CRP) and annual set-aside, which diverted millions of hectares of cropland from production. We evaluated the survival of pheasant chicks in Illinois in relation to these recent land-use practices. Specifically, our objectives were to determine if there were changes in chick survival during the 1980s and 1990s, and if there wer regional differences in chick survival related to land-use practices. We observed 574 broods along transect roa routes on the Sibley Study Area (SSA) in eastcentral Illinois, and 964 broods on routes throughout the pheasant range in Illinois. In spite of the increase in potential brood habitat on set-aside farmland, chick survival remained low from 1982 to 1996. For example, there was a 5-fold increase in the amount of forage legumes and small grains on the SSA from 1987-91 compared to 1975-81, with the average number of chicks per brood at 4.3 (1987-91) and 4.2 (1975-81). For survey routes throughout the Illinois pheasant range, the number of grassy fields (primarily narrow, linear tracts) in 1990 was positively correlated (r 2 = 0.15, P < 0.02, n = 37) with chicks per brood, but this relation explained only 15% of the variation. The lack of improvement in chick survival in recent decades relates to the pervasive clean farming practices in the Illinois pheasant range. More-over, most of the set-aside land in the Illinois pheasant range was under annual contract and seeded late to monotypic oats, which is cover of marginal value to foraging pheasant chicks.