Publications

A study of dabbling duck (Anatinae) nesting was conducted during 1971-73 on nine 12- to 54-ha Cropland Adjustment Program fields in the prairie pothole region of north-central South Dakota. The tall, dense vegetation was comprised of introduced cool-season grasses and legumes, primarily smooth bromegrass (Bromus inermis), intermediate wheatgrass (Agropyron intermedium), and alfalfa...

Nests of 195 upland sandpipers (Bartramia longicauda) on the Missouri Coteau of North Dakota generally were well concealed by grassy vegetation which ranged from 15.4-30.8 cm in height. Nest densities ranged from 0.3 per 40.5 ha on annually tilled croplands to 6.8 per 40.5 ha on native grasslands during the second growing season after a prescribed burn. Hatching success in native...

Abstract has not been submitted

Telemetry techniques were used to study habitat use and home range of 12 drake and 12 hen mallards (Anas platyrhynchos) in the forested region of north-central Minnesota during the 1968-72 breeding seasons. Circumneutral bogs and seasonal wetlands were the most frequently used communities; the lakeshore communities most used were sand-gravel, overhanging brush, and bog mat. Based on the

This paper describes the home range defense behavior observed when nonresident male red foxes were introduced into established home ranges of resident male-female pairs. In 12 observation periods, four intruders were introduced to each of three mated pairs which had been given three weeks to acclimate to a 4.05-hectare, fenced enclosure. The residents centered their activities around a...

Natural pox infection occurred in a free-living rough-legged hawk (Buteo lagopus) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (Buteo jamaicensis) but not in great horned owls (Bubo virginianus) following inoculation with case material. Death of the rough-legged...

Agricultural burning in an intensively farmed region within Manitoba's pothole district is shown to affect the nesting activities of ground-nesting ducks. All species, except Blue-winged Teal (Anas discors), preferred unburned nest cover, although success was higher in burned areas, where predators may have exerted less influence. Attitudes of farmers, burning chronology, and nest...

Abstract has not been submitted

Fourteen species of aquatic birds, including 11 species of ducks, were infested with leeches Theromyzon rude and Placobdella ornata near Yellowknife, Northwest Territories. Leeches infested 88% of 41 American Wigeon (Anas americana) and 31% of 86 Lesser Scaup (Aythya affinis) examined after death. Lesser Scaup captured by drive-trapping contained significantly more leeches than...

Abstract has not been submitted

Abstract has not been submitted

Published techniques for fitting data to nonlinear growth curves are briefly reviewed, most techniques require knowledge of the shape of the curve. A flexible growth curve developed by Richards (1959) is discussed as an alternative when the shape is unknown. The shape of this curve is governed by a specific parameter which can be estimated from the data. We describe in detail the fitting...