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G.W. Pendleton

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Arsenic (As) has been found at elevated concentrations in irrigation drainwater and in aquatic plants utilized by waterfowl. Mallard (Anas platyrhynchos) duckings received an untreated diet (controls) or diets containing 30, 100 or 300 ppm As added as sodium arsenate. After 10 weeks blood and tissue samples were collected for biochemical and histological examination. Arsenic accumulated significantly in brain and liver of ducklings fed 100 or 300 ppm but did not result in histopathological lesions. The 300-ppm dietary As concentration decreased overall growth (weight gain) in males, whereas all concentrations of As decreased overall growth and rate of growth in females. Food consumption was less during the first...
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Flotation of eggs in water and specific gravity of eggs of Black-crowned Night-Herons (Nycticorax nycticorax), Snowy Egrets (Egretta thula) and Great Egrets (Casmerodius albus) were evaluated as methods to determine date of hatching. Length of incubation and duration of hatching period were also documented for each species. Although species gravity was a better predictor of hatching date than egg flotation, both techniques were imprecise. The regression between specific gravity and the number of days before hatching differed among clutches, but not among eggs within clutches. Specific gravity of eggs predicted hatching data only to within 3.8 d for Snowy Egrets, adn 4.7 d for Black-crowned Night-Herons and Great...
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Gyrfalcon (Falco rusticolus) museum specimens in Moscow (73) and St. Petersburg (132) were divided into four color classes (gray, light gray, white gray, and white) and four longitudinal belts representing major physiographic regions of northern Russia. Gray variants predominated in the west and central regions. White birds were most common in extreme eastern Siberia, but were occasionally found even west of the Ural Mountains. Frequencies were as follows: European Russia 4% white, 50% gray (the remainder were intermediates); western Siberia 0% white, 58% gray; central Siberia 15% white, 42% gray; and eastern Siberia 47% white, 33% gray. Remarkably, in the easternmost subregion, white birds predominated even near...
Categories: Publication; Types: Citation; Tags: Journal of Raptor Research
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I analyzed data from the 1984 and 1986 Federal Waterfowl Hunter Questionnaire Survey (WHQS) to estimate the rate of return of name and address contact cards, to evaluate the efficiency of the Survey's stratification scheme, and to investigate potential sources of bias due to nonresponse at the contact card and questionnaire stages of the Survey. Median response at the contact card stage was 0.200 in 1984 and 0.208 in 1986, but was lower than 0.100 for many sample post offices. Large portions of the intended sample contributed little to the final estimates in the Survey. Differences in response characteristics between post office size strata were detected, but size strata were confounded with contact card return...
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We studied home range and movements of 15 radio-marked, juvenile Puerto Rican parrots (Amazona vittata) fledging from wild nests during summer and fall, 1985-87. When juvenile parrots remained in the nest valley, home ranges during 1986 (.hivin.x = 32 .+-. 10 [SE] ha, n = 4) were larger (P = 0.0079) than during 1987 (.hivin.x = 13 .+-. 6 ha, n = 5). After radio-marked parrots integrated into adult flocks, home ranges during 1986 (.hivin.x = 1,075 .+-. 135 ha, n = 3) were similar (P = 0.10) to 1987 (.hivin.x = 416 .+-. 62 ha, n = 2). Juvenile parrots restricted their movements to nest valleys an average of 58 .+-. 29 days following fledging. After joining adult flocks, juvenile parrots routinely flew between the...
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