Cold Resistance in the Young Ring-Necked Pheasant

Abstract

COLD resistance in many homoiothermic animals is not fully developed at birth, even though life after birth often entails resistance to low environmental temperatures. Because of less frequent utilization of sheltered burrows and dens for nesting, this problem would appear to be more acute in birds than in mammals. Some birds are further developed at hatching than others, and thereafter use no shelter beyond that afforded by the brooding hen. In northern United States the Ring-necked Pheasant is one of the most successful of these precocial species. In addition it is one of our most valuable game birds, and each year considerable resources are devoted to its propagation and management. Therefore a characterization of the development of cold resistance in this precocial species may well be of practical value in shedding light upon a possible mortality factor of early life.