Use of Cover by Pheasant Broods in East-Central Illinois

Abstract

During summers 1972 and 1973, 8 pheasant (Phasianus colchicus) hens with broods ranging from 1 to 12 weeks of age were monitored by radiotelemetry for movements and use of cover near Sibley, Illinois, in an area intensively farmed for production of corn and soybeans. Activity of all broods focused primarily in oats during day and night. Most young pheasants roosted in oats and hay, and did not become active until after sunrise. The daytime activity in oats and hay suggested that areas of suitable roosting cover also served as primary feeding areas. Use of cover did not appear to change in response to observed changes in wind and temperature. However, broods tended to use corn and soybeans to a greater extent during precipitation. Changes in use of cover by broods over the summer appeared to be more a function of brood age than of crop phenology or harvest. There was an apparent exponential increase in the ranges of broods during the 1st 9 weeks of age. Brood counts for the Sibley area suggested that rates of mortality of pheasant chicks during the 1st 12 weeks of life have increased significantly in recent years. It is postulated that because of the virtual elimination of small grains, forage grasses, and legumes, availability of insects and weedy forbs as food for pheasant chicks may be approaching critical proportions. J. WILDL. MANAGE. 43(2):334-346 This study was initiated to determine the use of cover by pheasant broods in east-central Illinois under current intensive agronomic practices. Past studies in Illinois (Robertson 1958, Joselyn et al. 1968, Labisky 1968) suggest that the availability of prime nesting habitat is a principal constraint to pheasant populations. However, in view of present land use in east-central Illinois (Fig. 1), mortality of pheasant chicks may be equally critical. Counts of pheasant broods made during July and August on standardized roadside census routes of the Sibley study area (SSA) indicate that survival rates of pheasant chicks during the 1st 10-12 weeks after hatching have decreased significantly in recent years (Richard E. Warner, unpublished data). The objectives were to determine what aspects of habitat were most crucial to the survival of pheasant chicks, and whether the Illinois Department of Conservation's program of managing roadside vegetation for nesting pheasants offers potential for providing critically needed brood habitat. The SSA was a desirable location to conduct this study because of the wealth of data on land use and pheasant populations collected there since the 1940's (Robertson 1958, Joselyn et al. 1968, Labisky 1968). I thank the Max McGraw Wildlife Foundation for primary support for the project. The Illinois Department of Conservation (P-R Project W-66-R) supplied a vehicle for radio-tracking. G. C. Sanderson, Illinois Natural History Survey, provided administrative and editorial assistance; W. R. Edwards contributed technical and editorial advice; W. W. Cochran supervised the design and construction of radiotelemetry equipment; G. B. Joselyn supervised the field study; S. P. Havera aided with the capture of hen pheasants and the fitting of transmitters to hens; and H. C. Schultz edited the manuscript. H. W. Norton, Professor of Statistical Design and Analysis, University of Illinois, confirmed the statistical tests used in the analysis; R. T. Dumke of the Wisconsin Department of Natural Resources offered advice concerning the attachment of radio transmitters. 334 J. Wildl. Manage. 43(2):1979 This content downloaded from 207.46.13.58 on Sat, 17 Sep 2016 05:34:55 UTC All use subject to http://about.jstor.org/terms USE OF COVER BY PHEASANT BROODS *Warner 335 100LAND USE FOR SIBLEY STUDY AREA, 1962-1974 90