Publications

Concentrations of over 100 ppm (100 mg/kg) selenium (Se) have been found in aquatic food chains associated with irrigation drainwater. Both quantity and composition of dietary protein for wild ducklings may vary in selenium-contaminated environments. Day-old mallard (Anas platyrhynchos) ducklings received one of the following diets containing 22% protein: unsupplemented (controls), 15...

We captured 2,182 mallards (Anas platyrhynchos) in eastcentral Arkansas and marked 730 with standard bands, 728 with 10 reward bands, and 724 with 'dummy' radio transmitters during November 1986-89 to estimate band reporting rates in the Mississippi Alluvial Valley (MAV). Assuming all transmitters were reported, reporting rates were 0.16 (SE=0.049) for standard bands and 0.34 (SE=0.081)...

Winter waterfowl surveys rarely use sampling methods, and little is known about the precision and biases of their population estimates. Consequently, we developed aerial transect surveys (n=5) in 4 strata comprising 16 substrata in the lower Mississippi Alluvial Valley during winters 1987-88 through 1989-90 to estimate mallard (Anas platyrhynchos) population indices and determine...

Tundra swans (Cygnus columbianus) of the eastern population were neckbanded in Maryland, North Carolina, and Alaska from 1966 through 1990. These swans were resighted and recaptured during autumn, winter, and spring, 1966-1990. Although the original motivation for this study involved swan movements, we wanted to use the resulting data to test hypotheses about sources of variation in swan...

Unmarked Double-crested Cormorants (Phalacrocorax auritus) (n = 523) were followed by airplane from Cat Island and Spider Island, two nesting colonies in Wisconsin, to their first landing site. Cormorants flew an average of 2.0 km from Cat Island (maximum 40 km) and 2.4 km from Spider Island (maximum12 km). The mean direction of landing sites differed seasonally for fights from Spider...

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...

Response rates to the Federal Waterfowl Hunter Questionnaire Survey (WHQS) have declined since the 1950's, suggesting that harvest estimates may be biased. Consequently, we investigated reasons for WHQS nonresponse using surveys of waterfowl hunters in Arkansas, California, Louisiana, Minnesota, New Jersey, and Texas. Sampling frames were constructed using lists of buyers of state...

In stage—based demography, animals are often categorized into size (or mass) classes, and size—based probabilities of surviving and changing mass classes must be estimated before demographic analyses can be conducted. In this paper, we develop two procedures for the estimation of mass transition probabilities from capture—recapture data. The first approach uses a multistate capture...

High concentrations of arsenic (As) and selenium (Se) have been found in aquatic food chains associated with irrigation drainwater. Total biomass of invertebrates, a maJor source of protein for wild ducklings, may vary in environments that are contaminated with selenium. Dayold mallard (Anas platyrhynchos) ducklings received an untreated diet (controls) containing 22% protein or diets...

Perhaps the great appeal of paleontological studies is that they inspire visions of past worlds richer and more interesting than our own. Yet, no matter how fascinating, these fossil creatures and their environments manifest a remoteness measured by more than geological time. But what if bones tell the story of a world that ought to still exist? In their long-awaited, twin monographs...

No abstract available.

No abstract available.