Breeding-bird censuses were taken on three 40-acre tracts of forest near Scranton, Pennsylvania, between May 1 and June 27, 1945. In late May, a 600-acre area enclosing one tract was sprayed by airplane with DDT in oil at the rate of 5 pounds per acre, a dosage several times greater than is considered necessary for gypsy moth control. Early in June, a 350-acre area enclosing the 2d tract was sprayed with 1 lb. of DDT per acre. The 3d tract was not treated. Within 3 days,after treatment with 5 lb. of DDT per acre, 7 birds representing 5 spp. had died, all apparently from DDT poisoning. Within 48 hrs. after treatment the population of living birds was much reduced, and there was only a flight increase within the next 2 weeks. The slight changes that took place in the populations of the tract sprayed with 1 lb. of DDT per acre and of the untreated tract were not attributed to DDT.