Behavior of Captive American Kestrels Hatched from o,p′-Dicofol Exposed Females

Abstract.

A two-generation laboratory study was conducted on captive American kestrels (Falco sparverius) to investigate the possible behavioral alterations from the compound o,p′-dicofol. Paired females were exposed to three levels of dicofol by oral gavage. Adults of the second generation, exposed only via the maternal dose of o,p′-dicofol at 5- and 20-mg/kg, displayed negatively correlated changes in reproductive behaviors. Second generation females showed a significant difference (p < 0.05) from control birds in the miscellaneous behavior category, where more time was spent picking at the rope perch, watching flies, laying down on the perch and other such displacement activities. Second generation 5-mg/kg males completed significantly fewer copulations (p < 0.05) than the corresponding control birds. The number of attempted or failed food transfers (a pair bonding activity) was also significantly higher (p < 0.05) in the second generation 5-mg/kg male group. Trials were conducted on second generation males to determine aggressiveness of these individuals when placed in a competitive arena. Primary perch sites and food items were obtained by control birds significantly (p < 0.05) more often than dicofol-exposed males. A bird's maternal dose had a significant negative effect (p < 0.05) on its ability to achieve a high rank order position.