Publications

Winter distribution and abundance of raptors were monitored within the Platte and North Platte river valleys. Data were collected along 265 km of census routes along the Platte and North Platte rivers during the winters of 1978-1979 and 1979-1980. Observations recorded during the second winter involved less observation time and were at somewhat different periods. There were 1574...

The use of fire to manage grasslands for wildlife is a relatively new management option for resource managers in the Northern Great Plains (NGP). Nearly all of the burning during the past 20-25 years has been conducted without the aid of specific guidelines for the region. This state-of-the-art set of recommendations was compiled because of this void.Records of 902 grassland fires...

This description of prairie basin wetlands of the Dakotas is part of a series of community profiles on ecologically important wetlands of national significance. The shallow wetlands of the Dakotas form the bulk of the portion of the Prairie Pothole Region lying within the United States. This region is famous as the producer of at least half of North America's waterfowl and an unknown...

We studied dispersal in a color-banded population of the Groove-billed Ani (Crotophaga sulcirostris) in Costa Rica. Eight percent of the young alive at the end of the breeding season bred on their natal territories the next year and 4% remained but did not breed. Thirteen percent dispersed successfully within the study area and bred in communal groups or simple pairs. The remaining 75%...

Included are the reasons for concern over the effects of agrichemicals (pesticides and fertilizers) on prairie-pothole wetlands in the United States. Summarized are the results of studies conducted to date on this topic. Identified is additional research needed to assess the impacts of agrichemicals on these wetlands. Included is a discussion of management strategies and initiatives...

Scolopacid sandpipers were studied from 1980 until 1984 during spring migration in North Dakota. Common species foraging together in mixed-species flocks differed in bill length most often by 20 to 30 percent (ratios from 1.2:1 to 1.3:1). Observed flocks were compared to computer generated flocks drawn from three source pools of Arctic-nesting sandpipers. The source pools included 51...

We estimated nest success of mallard (Anas platyrhynchos), gadwall (A. strepera), blue-winged teal (A. discors), northern shoveler (A. clypeata), and northern pintail (A. acuta) for 5 regions in North Dakota, South Dakota, and Minnesota, for 1-3 periods between 1966 and 1984, and for 8 habitat classes. We obtained composite estimates of nest success for regions and periods by weighting...

The settling of breeding habitat by migratory waterfowl is a topic of both theoretical and practical interest. We use the results of surveys conducted annually during 1955-81 in major breeding areas to examine the factors that affect the distributions of 10 common North American duck species. Three patterns of settling are described: homing, opportunistic, and flexible. Homing is...

No abstract available.

Kleptoparasitism on other raptors was one means by which Bald Eagles (Haliaeetus leucocephalus) secured food along the North Platte and Platte rivers during the winters of 1978-1980. Species kelptoparasitized were Ferruginous Hawk (Buteo regalis), Red-tailed Hawk (B. jamaicensis), Rough-legged Hawk (B. lagopus), Golden Eagle (Aquila chrysaetos), and Bald Eagle. Stealing of prey occurred...

We measured the effect of diet quality on variation in the seasonal pattern of Mallard (Anas platyrhynchos) reproduction. Twenty wild-strain hens, consisting of 10 sibling pairs, were maintained in captivity. One sib of each pair was fed an enriched diet, and the other was fed wheat. The wheat diet resulted in reduced clutch size, egg size, laying rate, number of nesting attempts, and...

Foods consumed by canvasback ducks (Aythya valisineria), food availability, and energetic relationships were studied on Navigation Pool 7 of the upper Mississippi River in 1978, 1979, and 1980. Canvasbacks fed primarily upon winter buds of American wildcelery (Vallisneria americana) and tubers of stiff arrowhead (Sagittaria rigida). In 1980, waterfowl consumed 40% of 380,160 kg of...