Organochlorine contaminants in passeriformes and other avian prey of the peregrine falcon in the western united states

Abstract

About 1,150 individuals of 38 species of Passeriformes and other small birds were collected in 1980 at 36 locations in eight western U.S. states for organochlorine (OC) chemical analysis. The bird carcasses (less beak, tarsi, gastrointestinal tract, and feathers) were combined by species and location (4 to 15 specimens per sample) into 124 composited samples for analysis. Also analyzed were 77 single specimens of four species, to assess variation in residue concentrations in individual birds. The chemicals detected (greater than 0.05 ppm) were the following (in order of frequency): DDE, polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH), heptachlor epoxide, oxychlordane, dieldrin and toxaphene. DDE accounted for 72% of total OC concentrations (ppm DDE/ppm total OCs) overall and PCBs accounted for 3%. DDE mean (geometric) residues were highest in tree swallows (Tachycineta bicolor Vieillot), 12.0 ppm; killdeer (Charadrius vociferus L.), 5.9 ppm; and Brewer's blackbirds (Euphagus cyanocephalus Wagler), 2.7 ppm. Eight migratory species showed mean DDE residues 13 times higher than those in four resident species (1.3 vs. 0.1 ppm, p < 0.05), but PCB residues were similar (0.03 vs. 0.02 ppm). Insectivorous species showed higher DDE, PCB and total OC residues than did either omnivores or granivores (p < 0.05). Males of some species showed higher residues of DDE, PCBs and total OCs than did females (p < 0.05). DDE residues, but not PCBs, in killdeer, Brewer's blackbirds and violet‐green swallows (Tachycineta thalassina Swainson) were significantly related (0.01 < p < 0.08) to latitude and longitude of origin. Concentrations of DDE in the carcass fat of some individual tree swallows and killdeer would be in the lethal range if 15 to 20% of the stored DDE were rapidly mobilized to the brain. Samples of 13 species contained DDE concentrations (greater than 3 ppm) considered sufficient to inhibit the normal reproduction of avian predators feeding on them. The evidence suggests that potentially harmful OC concentrations are present in certain western migrants and pose an even greater hazard to avian predators such as the peregrine falcon (Falco peregrinus Tunstall).

Environmental contaminants in Canadian shorebirds

“…Contaminant concentrations in marbled godwit and long-billed dowitcher from Quill Lakes were lower than residues found in these species at other inland sites in North America (DeWeese et al 1986;Hubbard and Schmitt 1988). However, White et al (1983) reported mean DDE levels of up to 5.7 μg g −1 ww in long-billed dowitchers collected along the south Texas coast in 1979-80. Stopovers in the Bay of Fundy have durations of 1 to 3 weeks, during which time the birds build up high levels of body fat (Hicklin 1987).…”

“…Blus et al 1985;Hothem and Powell 2000), (3) out of concern for the health of predatory species such as peregrine falcons which prey on shorebirds (e.g. DeWeese et al 1986;Schick et al 1987; Baril et al 1990;Court et al 1990;Custer and Myers 1990;Fyfe et al 1990;Banasch et al 1992;Johnstone et al 1996), and (4) in areas known to be important staging grounds (Napolitano et al 1992;McFarland et al 2002) or overwintering grounds (Hui 1998;Hui et al 2001). However, a survey of contaminants in shorebird species across several locations has not been undertaken, particularly not in Canada.…”

Transboundary pollution: Persistent organochlorine pesticides in migrant birds of the Southwestern United States and Mexico

“…Many of the efforts to document accumulation of POPs in North American migrant birds have been studies of raptors, especially the peregrine falcon and its prey [2,3,5,7,8,13]. During 1980 DeWeese et al [8] found that migrant species had higher DDE residues than resident species in the western United States and that concentrations in migrant species were inversely related to latitude of wintering grounds. Fourteen avian species, known prey of the peregrine falcon, were collected during 1981 in Arizona to determine levels of DDE and to identify threats of contaminants to peregrine falcons in the region [2].…”

“…The theory that migratory birds accumulate persistent organochlorine pesticides (POPs) during the winter in Latin America has been prevalent for years, particularly since DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) was banned in the United States in 1972 [1][2][3][4][5][6][7][8][9][10][11][12]. One reason for the popularity of this theory is that many important wintering areas in Mexico and Latin America are located near major agricultural areas, where pesticide applications are often high.…”

Organochlorines and mercury in the eggs of British Peregrines Falco peregrinus

“…Most of these prey species contained much lower organochlorine residues than eggs of the falcons themselves, in agreement with earlier studies (Cade et al 1968, Prestt & Ratcliffe 1972, White et al 1973, Pruett-Jones et al 1980, Enderson et al 1982, Lindberg el al. 1985, Deweese 1986). Residue levels in certain common prey types examined in the 1970s are shown in Figure 8.…”