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Rey C. Stendell

Publications and source records attributed to Rey C. Stendell.

At least 19 recordsLinked to original sources
USGS2003

Comparison of white-tailed kite food web dynamics among various habitats in California using stable isotope analysis

The White-tailed Kite (Elanus leucurus) was once a common raptor species in the southern United States. However, by the 1930s, the species was considered on the verge of extinction until the 1940s, when a trend towards recovery was apparent. These dramatic fluctuations may be related to changes in rodent prey base due to the conversion of native wetlands to agriculture. To investigate the effects of changes in habitat, land use practices, and prey base on kite populations, we collected tissue samples from kites, their prey, and vegetation at four different locations in California: Arcata, Coastal-Coniferous Forest; Davis, mixed Urban-Agricultural; Cosumnes, Mixed Wetland-Agriculture, and Santa Barbara, Coastal-Chaparral.

Book↗
USGS2001

Economic development and conservation of biological and cultural diversity in Yunnan Province, China

Chinese and American scientists are co-operating to develop concepts, strategies, agreements, and proposals in support of an economic development and sustainable ecosystems project in Yunnan Province, People's Republic of China. Yunnan's Provincial Government has initiated a major programme to develop and further utilise its biological resources to help improve economic conditions for its citizens. They are co-operating with the US Geological Survey (USGS) on evaluation and management of biological resources so economic development will be compatible with sustainable ecological systems. Scientists from the USGS and co-operating universities will provide expertise on synthesising biological data, conducting a Gap Analysis for the Province, evaluating innovative economic opportunities, and designing an effective education, training, and outreach programme.

Environmental Development and Sustainability↗
USGS1991

Eggshell modifications in captive American kestrels resulting from Aroclor 1248 in the diet

American kestrels ( Falco sparverius ) were fed diets containing 3 μg/g Aroclor ® 1 1248 or control diets from mid-January until July. Eggs were removed from first clutches 2 to 4 days after laying ceased and shell thickness and shell dimensions were measured. Contents of the third egg of each clutch, the carcasses of all adults that received Aroclor ® 1248 and of three males and three females that received the control diet were analyzed for DDE, Aroclors ® 1248, 1254 and 1260, and dieldrin. Concentrations of PCBs, DDE and dieldrin were significantly higher (P < 0.03) in eggs and carcasses from treated adults than in controls. Shell thickness and shell thickness index of eggs from treated adults were reduced 5.0% (P < 0.0001) and 4.8% (P < 0.0001), respectively, from those of controls.

Archives of Environmental Contamination and Toxico↗
USGS1989

Accumulation of lead and organochlorine residues in captive American kestrels fed pine voles from apple orchards

Pine voles (Microtus pinetorum) were collected from pesticide-treated orchards in New York and fed to 3 captive American kestrels (Falco sparverius) for 60 days to evaluate potential hazards from soil-borne persistent insecticides. Three control kestrels were fed uncontaminated laboratory mice (Mus musculus). The pine voles contained an average of 38 ppm lead, 48 ppm DDE and 1.2 ppm dieldrin (dry weight). The kestrels accumulated sublethal amounts of lead (1 ppm lead wet weight) in their livers. In contrast, DDE and dieldrin accumulated in the tissues and brains of kestrels to toxicologically significant concentrations. Control kestrels remained healthy and accumulated insignificant concentrations of the contaminants. The results indicated raptors may not be significantly at risk from lead residues in soil and biota following field applications of lead arsenate. However, sublethal effects may be expected from the level of contamination by organochlorine pesticides. raptors may not be significantly at risk from lead residues in soil and biota following field applications of lead arsenate. However, sublethal effects may be expected from the level of contamination byorganochlorine pesticides. lead wet weight) in their livers.

Journal of Wildlife Diseases↗
USGS1988

Organochlorine and mercury residues in Swainson's and ferruginous hawk eggs collected in North and South Dakota, 1974-79

Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury were measured in eggs of Swainson's hawks ( Buteo swainsoni ) and ferruginous hawks ( B. regalis ) collected in North and South Dakota during 1974–79. DDE was the most common compound detected in the eggs, but residues were below levels known to have adverse effects on reproduction. Other organochlorine compounds and mercury were found at low levels. Eggs of ferruginous hawks tended to contain more compounds with higher residues than eggs of Swainson's hawks.

Environmental Monitoring and Assessment↗
USGS1980

Lead residues in sora rails from Maryland

During September and October, mi- grating sora rails (Porzana carolina) use tidal marshes of the Patuxent River in Maryland, where they have been hunted for many years. Spent shot accumulates in the marsh during the rail hunting sea- son, and some shot is ingested by the birds. Twelve percent of gizzards from rails collected at the marsh during 1965- 73 contained lead shot (Artmann and Martin 1975). Effects of ingested lead on waterfowl are well documented (Bellrose 1959), although effects on other species of wild birds are not well known. In this note we report lead residues in liver and bone tissues of sora rails collected at the Patuxent River marshes in 1976.

Journal of Wildlife Management↗
USGS1979

Organochlorine residues in young herons from the upper Mississippi River-1976

Chicks of great blue herons (Ardea herodias) from four heronaries located near South St. Paul, Royalton, and Wabasha, Minnesota, and La Crosse, Wisconsin, were analyzed for organochlorines, Highest mean wet-weight concentrations, 6.43 ppm PCBs. 1.31 ppm DDE, and 1.90 ppm sigma DDT, were found in the South St. Paul chicks. Among chicks from the other three heronries, most levels were similar, but were significantly lower than levels in South St. Paul chicks. Lowest mean organochlorine levels, 0.37 ppm DDE, 0.38 ppm sigma DDT, and 0.22 ppm PCBs, were found in chicks from Royalton. All birds from South St. Paul and La Crosse contained residues of DDT and TDE whereas only one of the 10 birds from Royalton contained DDT and one contained TDE residues. Five of the 12 birds from Wabasha contained DDT; eight contained TDE. Except for PCB residues in La Crosse heron chicks, the rate of organochlorine residue accumulation in the birds was generally less than the rate of dilution caused by growth.

Pesticides Monitoring Journal↗
USGS1978

Survival and reproductive success of black ducks fed methyl mercury

A diet containing 3 ppm mercury was fed to black ducks (Anas rubripes) for periods of 28 weeks during two consecutive breeding seasons. Clutch size, egg production, number of eggs incubated, hatchability and survival of ducklings were lower during both years in hens fed mercury. Reduced hatchability and poor duckling survival were the most harmful effects. During 2 years, 13 pairs of breeders fed mercury produced only 16 ducklings that survived 1 week compared with 73 ducklings from 13 pairs of controls. Mercury residues in eggs, embryos and ducklings averaged about 30% lower during the second breeding season compared with first year results. Third eggs laid by treated hens contained a mean of 6?14 and 3?86 ppm mercury during the first and second years. Whole embryos that failed to hatch contained means of 9?62 and 6?08 ppm mercury during the first and second years. Brains of dead ducklings contained between 3?25 and 6?98 ppm mercury and exhibited lesions characteristic of mercury poisoning. Relative tissue mercury levels for treated adult breeders were: feathers > liver > kidney > breast muscle > brain. Mercury levels in males and females did not differ.

Environmental Pollution↗
USGS1977

Shell thinning and reproductive impairment in black ducks after cessation of DDE dosage

Captive black ducks ( anas rubripes ) were fed dietary DDE [1,1-dichloro-2,2- bis ( p -chlorophenyl)ethylene] at 10 ppm (dry weight; about 2 ppm on a natural diet basis) for 2 breeding seasons, then untreated feed for 2 succeeding years. Residues of DDE in the carcasses of adults declined 90% during the 2-year clean-up period. Following 2 years of dietary DDE, mean residues in eggs reached 64.9 ppm. Even after 2 years on clean feed, DDE residues in the eggs averaged 6.2 ppm or 9.5% of the mean DDE level reached after 2 years on treated feed. Shells of eggs from treated hens were about 20% thinner than shells of eggs from controls. Stoppage of DDE dosage resulted in progressively thicker shells, yet even after 2 years on untreated feed hens laid eggs with shells about 10% thinner than control hens. After DDE was removed from the diet, DDE residues in the eggs decreased, shell thickness increased, and reproductive success improved. Hens previously exposed to DDE, but then fed clean feed for 2 years, still produced significantly fewer surviving ducklings than did control hens.

Archives of Environmental Contamination and Toxico↗
USGS1977

Organochlorine and mercury residues in canvasback duck eggs, 1972-73

Eggs of canvasback ducks (Aythya valisineria) from several major breeding areas were analyzed for organochlorine and mercury residues. Polychlorinated biphenyls (PCBs) were detected in 96 of 97 eggs, in concentrations up to 29 ppm (wet wt.). DDE occurred in 79 percent of the samples with a maximum residue of 12 ppm (wet wt.). DDT, DDD, dieldrin, hexachlorobenzene, cis-chlordane, heptachlor epoxide, and oxychlordane were detected less frequently. Mercury was detected in only 6 of 34 eggs analyzed. Most of the eggs contained concentrations of organochlorines and mercury below levels known to cause adverse effects on avian survival or reproduction.

Journal of Wildlife Management↗
USGS1977

Waterfowl exposure to lead and steel shot on selected hunting areas

Gizzards and wingbones from immature mallards ( Anas platyrhynchos ), pintails ( Anas acuta ), black ducks ( A. rubripes ), and Canada geese ( Branta canadensis ) were collected from 12 national and stat hunting are.as during the hunting season of 1974-75. The gizzards were examined for the occurrence of lead and steel shot and the wingbones were analyzed for lead residues. Incidence of lead shot in gizzards ranged from 1.3 percent in mallards from Monte Vista National Wildlife Refuge to 29 percent in pintails from Sauvie Island Wildlife Management Area. Lead in wingbones ranged from trace residues (<0.5 ppm) to 345 ppm. The incidence of steel shot in gizzards surpassed lead shot on some refuges that have had mandatory steel shot programs. There was a significant correlation between frequency of lead shot in gizzards and lead residues in wingbones.

Journal of Wildlife Management↗
USGS1977

Impact of estuarine pollution on birds

Pollution of estuaries affects bird populations indirectly through changes in habitat and food supply. The multi-factor pollution of Chesapeake Bay has resulted in diminution of submerged aquatic plants and consequent change in food habits of the canvasback duck. Although dredge-spoil operations can improve wildlife habitat, they often result in its demise. Pollution of estuaries also affects birds directly, through chemical toxication, which may result in outright mortality or in reproductive impairment. Lead from industrial sources and roadways enters the estuaries and is accumulated in tissues of birds. Lead pellets deposited in estuaries as a result of hunting are consumed by ducks with sufficient frequency .to result m large annual die-offs from lead poisoning. Fish in certain areas, usually near industrial sources, may contain levels of mercury high enough to be hazardous to birds that consume them. Other heavy metals are present in estuarine birds, but their significance is poorly known. Oil exerts lethal or sublethal effects on birds by oiling their feathers, oiling eggs and young by contaminated parents, and by ingestion of oil-contaminated food. Organochlorine chemicals, of both agricultural and industrial origin, travel through the food chains and reach harmful levels in susceptible species of birds in certain estuarine ecosystems. Both outright mortality and reproductive impairment have occurred.

Book chapter↗
USGS1976

Chemical pollutants in field-collected canvasback tissues, eggs, and food materials

In 1972 studies began on the levels of environmental pollutants in canvasback tissues, eggs, and food items. The purpose of the studies were to determine if the levels of toxic chemicals found in canvasbacks were of the magnitude to cause problems affecting reproduction and survival. Overall, levels of organochlorine pesticides and PCB's were low in canvasbacks and their eggs. Some individual birds, however, laid eggs with elevated residues of DDE (12.1 ppm) or PCB's (28.6 ppm). There was no significant difference between eggshell thicknesses of 1972-73 and pre-1946 collections. About 12% of the canvasbacks analyzed had elevated levels of blood lead with reduced ALAD enzyme activity. Adult canvasbacks collected from the Chesapeake Bay in 1975 had moderate to high levels of cadmium in their kidneys. Cadmium, in excessive amounts is very toxic and can curtail spermatogenesis in male birds. Although no single toxic chemical found in wild canvasbacks appears to be a major factor in population declines, the cumulative effects of sublethal levels of all the pollutants may render birds susceptible to disease, hunting pressure or predation.

Book chapter↗