Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange
Abstract
Studies to determine the effects of dieldrin on social hierarchy of pheasants and chickens were initiated in 1970. Social interactions were observed among groups of pheasant chicks, adult cock and hen pheasants and peck-order development among groups of young pheasants. To determine the effects of dieldrin on the pecking behavior of individual birds, pairs of pheasants and pairs of chickens were placed in a neutral cage. When patterns of dominance and subordination were consistent, dieldrin in capsules (4 mg to pheasants and 6 and 10 mg to chickens twice weekly) was given to one member of each pair and birds were observed ·for changes in pecking behavior. Toward the end of the study, one bird from each of the pheasant chick groups was given 4 mg of dieldrin twice a week. Fights were observed among pheasant chicks at 3 weeks of age, and it was concluded that aggressive behavior and peck-order development began at this time. Only in smaller groups (two to five birds) could a rank be determined based on the total number of each individual\u27s interactions. Groups of adult pheasants also displayed peck-orders, usually not linear. Weight, previous dieldrin treatment parental dieldrin treatment and ear tuft length had no effect on the peck-orders. There were no correlations between sex and rank in the pheasant chick, groups. Dominance-subordination patterns of pheasants and chickens were not affected by dieldrin administration. Although a few reversals of peck order occurred, none were statistically significant
