The Effects of DDT upon the Survival and Growth of Nestling Songbirds

Abstract

DDT at 3 pounds per acre was applied as an oil spray for two years to 40 acres of open abandoned fields containing 293 nest boxes. 303 house wren nestlings were under observation during that time. 28% survival resulted in the sprayed area in 1949 compared to 86% in the check. In 1950, when spray was applied before peak of 1st brood hatch, survival in sprayed ares was 70% compared to 73% in check. Average weights of 1st brood nestlings in both years were significantly lower than of checks. Weights of second brood nestlings in 1949 were slightly lower than those of check, while in 1950 they approximated each other.