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Publications

These publications showcase the significant science conducted in our Science Centers.

Filter Total Items: 16784

Decline and present status of breeding peregrine falcons in Oregon

In 1979, only one Peregrine Falcon pair (they fledged two young) and a single adult male were located. A population decline east of the Cascades began in rhe 1930's, probably resulting from a climatic change (drought); however, a statewide decline began in the late 1940's, accelerated in the 1950's, and by the 1960's few pairs remained. The statewide decline closely paralleled the pattern of DDT u
Authors
C. J. Henny, M.W. Nelson

The Mayfield method of estimating nesting success: A model, estimators and simulation results

Using a nesting model proposed by Mayfield we show that the estimator he proposes is a maximum likelihood estimator (m.l.e.). M.l.e. theory allows us to calculate the asymptotic distribution of this estimator, and we propose an estimator of the asymptotic variance. Using these estimators we give approximate confidence intervals and tests of significance for daily survival. Monte Carlo simulatio
Authors
Gary L. Hensler, J. D. Nichols

Coral snake mimicry: does it occur?

Field observations and experimental evidence refute previous objections to the coral snake mimicry hypothesis. Concordant color pattern variation spanning hundreds of miles and several presumed venemous models strongly suggests that several harmless or mildly venemous colubrid snakes are indeed mimics of highly venemous elapids.
Authors
H.W. Greene, R.W. McDiarmid

Species differences in hematological values of captive cranes, geese, raptors, and quail

Hematological and serum chemical constituents of blood were determined for 12 species, including 7 endangered species, of cranes, geese, raptors, and quail in captivity at the Patuxent Wildlife Research Center. Means, standard deviations, analysis of variance by species and sex, and a series of multiple comparisons of means were derived for each parameter investigated. Differences among some speci
Authors
G.F. Gee, J. W. Carpenter, Gary L. Hensler

Residues of persistent pesticides decreasing

No abstract available.
Authors
J.B. Graves, G.U. Mayfield, J.D. Newsom

The effects of ingested petroleum on the maphthalene-metabolizing properties of the liver tissue in seawater-adapted mallard ducks (Anas platyrhynchos)

Hepatic mixed function oxidase activities were estimated in seawater-adapted mallard ducks (Anas platyrhynchos) that had been consuming food contaminated with one of five different types of crude oil. After 50 days of exposure to contaminated food, enzyme activities of liver microsomal preparations were assessed in terms of their naphthalenemetabolizing properties in vitro. Although dose-dependent
Authors
J. Gorsline, W. N. Holmes, J. Cronshaw

Acute toxicities of toxaphene and endrin to larvae of seven species of amphibians

Seven species of amphibian larvae were exposed to toxaphene and endrin in a continuous-flow dosing system to determine differences in sensitivity to the two compounds, EC50 and LC50 estimates varied from those for Rana sphenocephala by no more than one order of magnitude when calculated on the basis of intended concentrations. Removal of pesticides from water by the test animals was significant an
Authors
R.J. Hall, D. M. Swineford

Growth of mallards fed phosphamidon for 13-day periods during three different developmental stages

Mallard ducklings (Anas platyrhynchos) were exposed to a 13-day dietary treatment of 0, 0·5 or 5·0 ppm phosphamidon at one of three successive age intervals (5–17 days, 18–30 days, or 31–43 days) during a 10-week growth period. Weekly measurements of body weight, wing length, primary feather length, and bill length revealed slower development of primary feathers in those birds treated from 5 to 17
Authors
S. Haseltine, Gary L. Hensler

Avoidance behavior of young black ducks treated with chromium

Pairs of adult black ducks (Anas rubripes) were fed a diet containing 0, 20, or 200 ppm chromium in the form of chromium potassium sulfate. Ducklings from these pairs were fed the same diets as adults and were tested for their avoidance responses to a fright stimulus. Neither level of chromium had a significant effect on avoidance behavior.
Authors
G. H. Heinz, S. D. Haseltine

A review of bufflehead sex and age criteria with notes on weights

Summary: Buftleheads Bucephala albeola were collected along the Oregon coast during the hunting season. Birds were first sexed and aged upon cloacal and internal characteristics. Results were then compared with data derived from wing plumage. A small change was made in Carney's (1964) wing plumage key to improve its accuracy. Although only a few studies have been made of Bufflehead weights, i
Authors
C. J. Henny, J.L. Carter, Barbara J. Carter