DDE effects on reproduction of ring doves

Reproductive performance was measured for 126 days in twelve pairs of ring doves (Streptopelia risoria) fed a diet containing 40 ppm of p,p'-DDE and in twelve other pairs given untreated food. The DDE-treated doves took an average of 212">2 1/2 times longer to renest than controls, produced 13·5% fewer eggs/clutch, had 10% thinner eggs, and experienced twice as great mortality of young; all these differences were statistically significant. Hatchability was also lower but not significantly so. Control birds nested forty-nine times during the study, laying two eggs in each clutch. DDE-treated birds nested only thirty-three times, laying an average of 1·7 eggs/clutch. The combined effects of DDE on reproduction resulted in only ten young being successfully raised by DDE-treated pairs versus thirty-five being raised by controls.