Bird Mortality Following DDT Spray for Dutch Elm Disease

Abstract

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

Environmental contaminants in Canadian shorebirds

“…Diagnostic levels for carcasses have not been determined for birds, rather brain or egg concentrations are generally used to determine critical threshold levels. However, Wurster et al (1965) suggested ΣDDT levels of >30 μg g −1 ww in carcasses of a variety of passerines and woodpeckers as a minimum lethal threshold. The maximum ΣDDT levels found in shorebird carcasses in this study were 5% of the lethal threshold suggested by Wurster et al (1965).…”

“…However, Wurster et al (1965) suggested ΣDDT levels of >30 μg g −1 ww in carcasses of a variety of passerines and woodpeckers as a minimum lethal threshold. The maximum ΣDDT levels found in shorebird carcasses in this study were 5% of the lethal threshold suggested by Wurster et al (1965). Morrison and Kiff (1979) found little change in eggshell thickness since the advent of DDT use in 1947 and the 1960-70s in any of the 31 shorebird species surveyed, and suggested that shorebirds are not particularly sensitive to DDEinduced eggshell-thinning.…”

Chlorinated Hydrocarbons and Reproduction of a South Swedish Population of Whitethroat Sylvia communis

“…Probably the same cuckoo frequented this area in both years (Chance 1940, Makatsch 1953 Analysis of brain tissue is the best way to decide if insecticides have been lethal to a bird (Wurster et al 1965). All these eggs were in neighbouring nests in the eastern part of the area.…”

Profiles of Organochlorine Pesticides in Earthworms from Urban Leisure Areas of Beijing, China

“…There are substantial evidences that DDT accumulated from contaminated earthworms had killed large numbers of robins and other thrushes in the 1950s to 1970s (Barker 1958;Wallace 1962;Wurster et al 1965;Bailey et al 1974;Beaver 1980). Lethal brain residues in several species of bird were measured at 300-400 mg kg -1 (Stickel et al 1984).…”