Adoptive Behavior of Caged Pheasants Exposed to Chicks and Dieldrin

Abstract

Adoption studies in 1969 and 1970 showed respectively that 37 and 49% of confined hen pheasants (Phasianus colchicus) adopted and brooded introduced chicks, 38 and 26% intentionally killed chicks, and 18 and 11% neither adopted nor killed chicks. The hens were exposed to only sound stimulus or sight-and-sound stimuli from chicks 8 to 22 days just prior to adoption tests. There was no difference in rates of adoption or killing of chicks by hens subjected to the two treatments. Stublethal doses of dieldrin had no apparent effect on chick adoption under conditions of this study. INTRODUCTION Many workers have attempted to induce parental behavior in gallinaceous birds. Stanford (1952) studied chick adoption in bobwhite quail (Colinus virginianus) for the purpose of propagation and release of adult quail with adopted broods. Most studies of parental behavior in pheasants have involved administration of hormones, especially prolactin, in an attempt to induce broodiness for stocking purposes. Breitenbach and Meyer (1959) studied pituitary prolactin levels at different stages of the reproductive cycle, and Crispens (1956) and Nelson (1963) gave injections of prolactin to hen pheasants for the purpose of propagation and subsequent release of hens and adopted broods. Goodale (1916) induced broody behavior in capons by introduction of chicks, and Burrows and Byerly (1938) were able to stimulate broodiness in domestic hens by placing them singly in cages with chicks. Ramsay (1953) stated that visual and auditory stimuli alone may trigger broodiness in fowl. He also induced broodiness in 14 bantam hens by introducing small chicks. A field study by Linder and Agee (1965) demonstrated that stimuli provided by pheasant chicks caused nesting pheasant hens to abandon their clutches. They theorized that in areas of high pheasant density the total number of young produced may be limited by the number of unattached chicks which come in contact with nesting hens. During recent years emphasis has been placed on testing effects of sublethal levels of insecticides on behavior. Sheep exposed to dieldrin exhibited a decrement in the performance of a vigilance task (Sandler et al., 1969). However, a significant effect on detour behavior in sheep could not be detected (Sandler et al., 1968). Jackson et al. (1970), studying salmon parr (Salmo salar) and yearling speckled trout (Salvalinus fontinalis), concluded that sublethal doses of DDT, per se, 1 South Dakota Agricultural Experiment Station Journal Series No. 1006. 2 Present address: Lt. Kay L. Cool, 504-52-5128, Co. A 2132 Armor, APO 09045, New York.