Bird Mortality Following DDT Spray for Dutch Elm Disease

摘要: Avian populations in Hanover, N. H., a town that has sprayed its elms with DDT for many years an attempt to control Dutch elm disease, were compared those Norwich, Vt., 1 mile (1.6 km) west of Hanover never sprayed. applied 109 lb DDT/acre (2.1 kg/hectare) April 1963, then used Methoxychlor 1964. Population surveys taken regularly during spring and early summer these years, dead birds collected both towns, 106 analyzed DDT, DDE, DDD. Severe mortality resident migrant occurred the evidence implicates as cause. Robin loss was estimated at 70% population, or 350 400 individuals, but among other species widely varied feeding habits also substantial. Feeding suggest some acquired toxicant by eating living insects carrying presenting paradox survival intended victims, death, instead, insectivorous birds. Organ whole bird analyses are presented criteria establishing cause death discussed. Most had been converted DDE DDD, residues found all organs analyzed. reduced, not eliminated following application 1964; losses believed caused residual soil. There no poisoning 1964, though