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C.S. Hulse

Publications and source records attributed to C.S. Hulse.

8 recordsLinked to original sources

Dermal insecticide residues from birds inhabiting an orchard

The US Environmental Protection Agency conducts risk assessments of insecticide applications to wild birds using a model that is limited to the dietary route of exposure. However, free-flying birds are also exposed to insecticides via the inhalation and dermal routes. We measured azinphos-methyl residues on the skin plus feathers and the feet of brown-headed cowbirds ( Molothrus ater ) in order to quantify dermal exposure to songbirds that entered and inhabited an apple ( Malus x domestica ) orchard following an insecticide application. Exposure to azinphos-methyl was measured by sampling birds from an aviary that was built around an apple tree. Birds sampled at 36 h and 7-day post-application were placed in the aviary within 1 h after the application whereas birds exposed for 3 days were released into the aviary 4-day post-application. Residues on vegetation and soil were also measured. Azinphos-methyl residues were detected from the skin plus feathers and the feet from all exposure periods. Our results underscore the importance of incorporating dermal exposure into avian pesticide risk assessments.

Environmental Monitoring and Assessment

Field evaluation of an avian risk assessment model

We conducted two laboratory subacute dietary toxicity tests and one outdoor subacute dietary toxicity test to determine the effectiveness of the U.S. Environmental Protection Agency's deterministic risk assessment model for evaluating the potential of adverse effects to birds in the field. We tested technical-grade diazinon and its D Z N- 50W (50% diazinon active ingredient wettable powder) formulation on Canada goose (Branta canadensis) goslings. Brain acetylcholinesterase activity was measured, and the feathers and skin, feet. and gastrointestinal contents were analyzed for diazinon residues. The dose-response curves showed that diazinon was significantly more toxic to goslings in the outdoor test than in the laboratory tests. The deterministic risk assessment method identified the potential for risk to birds in general, but the factors associated with extrapolating from the laboratory to the field, and from the laboratory test species to other species, resulted in the underestimation of risk to the goslings. The present study indicates that laboratory-based risk quotients should be interpreted with caution.

Environmental Toxicology and Chemistry

Decomposed gosling feet provide evidence of insecticide exposure

Canada goose goslings were exposed to turf sprayed with D · Z · N® diazinon 50W application (2.24 kg a.i./ha). The control plot was subjected to a water application. One foot from each bird was placed outdoors for 7 d to decompose and the other foot was kept frozen. Diazinon residues were analyzed on both feet. Results showed that diazinon was detected from undecomposed and decomposed feet of the birds. Diazinon residues were below the level of detection (<0.01 ppm, a.i.) on the feet from the control goslings. Decomposed feet may be used for determining insecticide exposure when the traditional matrices are not available.

Environmental Monitoring and Assessment

Insecticide residues on weathered passerine carcass feet

Nine brown-headed cowbirds ( Molothrus ater ) were exposed to turf sprayed with either EarthCare® (25% diazinon; 4.77 L a.i./ha) or Ortho-Klor® (12.6% chlorpyrifos; 5.21 L a.i./ha). Birds were euthanized and one foot from each bird was weathered outdoors for up to 28 days and the other foot was kept frozen until residue analysis. When compared to the unweathered feet, feet weathered for 28 days retained 43% and 37% of the diazinon and chlorpyrifos, respectively. Insecticide residues were below the level of detection (1.0 ppm) on control feet. Weathered feet may be used for determining organophosphorus insecticide exposure to birds.

Environmental Forensics

Reproduction and health of mallards fed endrin

Concentrations of 0, 1 and 3 ppm endrin in dry duck mash were fed to mallards ( Anas platyrhynchos ) starting in December, and health and reproduction were measured the following spring and summer. One male fed 3 ppm endrin died with 2.0 ppm endrin (wet weight), a diagnostically lethal level, in its brain. Birds fed 1 ppm endrin reproduced as well as, if not better than, controls. Birds fed 1 ppm endrin had significantly greater hatching success of fertile eggs than did those fed 0 or 3 ppm, and their clutches hatched significantly earlier than did those of birds fed 3 ppm. Mallards fed 3 ppm endrin appeared to reproduce more poorly than controls, but this finding must be regarded with caution because the results of statistical tests often were not significant. Endrin accumulated in eggs to a mean of 1.1 and 2.9 ppm (wet weight) when fed to hens at 1 and 3 ppm. The concentration of endrin in the carcasses of adults was similar to that in eggs, but the concentration in the fat of adults was about 4 to 7 times higher than in eggs.

Environmental Toxicology and Chemistry

Trends and effects of organochlorine residues on Oregon and Nevada wading birds, 1979-83

The incidence of DDT (parent compound) declined significantly in the eggs of Black-crowned Night-Herons (Nycticorax nycticorax), White-faced Ibis (Plegadis chihi), and Black-necked Stilts (Himantopus mexicanus), and showed a downward trend in Snowy Egrets (Egretta thula). Mean DDE residues (breakdown product of DDT) in eggs declined significantly in Black-crowned Night-Herons and showed a downward trend in Black-necked Stilts and Snowy Egrets; however, no trend was apparent for White-faced Ibis. Some night-herons, egrets, and ibis laid thin-shelled eggs that cracked; eggshell thickness was negatively correlated with DDE residues in the egg contents. Ibis were the most sensitive species to DDE- induced shell thinning. Generally, reduced reproductive success for ibis started at lower DDE egg residues (3 ppm) than for either Snowy Egrets (5 ppm) or night-herons (8 ppm). Egg residue profiles, band recoveries, biotelemetry studies, and residues in fish and other prey items implicate the southwestern United States (a wintering area) as an important source of DDT-DDE that caused the most serious reproductive problem encountered during the study (in night-herons nesting at Ruby Lake, Nevada). Available evidence indicates that the three other species, together with night- herons from Oregon and Idaho, winter in Latin America.

Idaho, Nevada, Oregon

Organochlorine pesticides in plasma of migrating peregrine falcons at Padre Island, Texas, Spring 1978-80 vs. Spring 1984

A spring concentration of migrating Peregrine Falcons (Falco peregrinus) was first discovered at Padre Island, Texas, in April 1978. The birds were first captured and blood-sampled for monitoring residue burdens and trends in the late 1970' s. Only 29 Peregrines were sampled in 1978 and 1979, but 111 were sampled in 1980. The initial investigation showed that DDE in the plasma of spring migrants returning from Latin America for the first time declined significantly during the study (through 1980). In the spring of 1984, 48 Peregrines were captured at Padre Island with blood samples again collected. This report will compare plasma residue data from the earlier study with residues obtained in 1984.

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