Courtship Behavior of Captive American Kestrels (Falco sparverius) Exposed to

Abstract. Polychlorinated biphenyls (PCBs) adversely affect reproduction in birds. Captive adult male and female American kestrels (Falco sparverius) were studied to investigate the potential behavioral and hormonal alterations during the court-ship period resulting from clinical exposure to PCBs. American kestrels ingested 7 mg/kg/body weight/bird/day of a 1:1:1 mixture of Aroclors 1248, 1254, and 1260 through their diet of day-old cockerels. The dietary dosage of Aroclors resulted in environmentally relevant total PCB residues in the eggs, aver-aging 34.1 mg/g wet weight (geometric mean). There was no difference between treatment and control birds in the circulat-ing levels of total androgens (p 5 0.44) or in 17b-estradiol (p 5 0.29), one week following pairing. Male kestrels exposed to dietary PCBs exhibited significantly more sexual behaviors (p 5 0.034) and flight behaviors (p 5 0.026) than the contro