Publications

In 1979 the US Fish and Wildlife Service published and adopted a classification of wetlands and deepwater habitats of the United States. The system was designed for use in a national inventory of wetlands. It was intended to be ecologically based, to furnish the mapping units needed for the inventory, and to provide national consistency in terminology and definition. We review the...

These maps show changes in the distribution and abundance patterns of some North American birds for the last 20 years. For each species there are four maps, each representing the average distribution and abundance pattern over the five-year periods 1970-1974, 1975-1979, 1980-1984, and 1985-1989. The maps are based on data collected by the USFWS/CWS Breeding Bird Survey (BBS). Only BBS...

This report on the distribution, abundance, and health of our nation's biological resources is the first product of the National Biological Service’s Status and Trends Program. This information has many potential uses: it can document successful management efforts so resource managers will know what has worked well; it can identify problems so managers can take early action to restore...

Point counts of birds are made for many reasons, including estimating local densities, determining population trends, assessing habitat preferences, and exploiting the activities of recreational birdwatchers. Problems arise unless there is a clear understanding of what point counts mean in terms of actual populations of birds. Criteria for conducting point counts depend strongly on the...

The skua and penguin with title billing in this book are specifically the South Polar Skua (Catharacta maccormicki) and the Adélie Penguin (Pygoscelis adeliae), More specifically, they are the populations of those two species that breed at Cape Bird on Ross Island, Antarctica (77°14'S, 16628'E), where the author and his students and colleagues conducted research during 1965-1970, Young...

The Upper Mississippi River is an important habitat corridor for migratory birds and other wildlife, and it supports an important commercial and sport fishery. A study was initiated by the U.S. Fish and Wildlife Service in 1991 to describe Double-crested cormorant (Phalacrocorax auritus) distribution and abundance on the Upper Mississippi River throughout the year to better understand...

Although sampling plans and estimators of abundance have good theoretical properties, their performance in real situations is rarely assessed because true population sizes are unknown. We evaluated widely used sampling plans and estimators of population size on 3 known clustered distributions of pronghorn (Antilocapra americana). Our criteria were accuracy of the estimate, coverage of 95...

We used results from simulation models to demonstrate the benefit-cost ratios of habitat management to increase the number of mallard (Anas platyrhynchos) recruits produced. The models were applied to hypothetical 2-habitat landscapes comprised of managed and unmanaged habitat. Managed habitats were predator barrier fencing and CRP cover; unmanaged habitat was grassland. As the amount of...

Although nonparametric statistical methods have a role to play in the analysis of data, often their virtues are overstated and their deficiencies overlooked. A recent Special Feature in Ecology advocated nonparametric methods because of an erroneously stated advantage that they require no assumptions regarding the distribution underlying the observations. The present paper points out...

No abstract available.

Previous studies have shown that habitat provided by the Conservation Reserve Program (CRP), a feature of the 1985 farm bill, is used by many birds. The present study quantitatively assesses the importance of the CRP by estimating changes in breeding-bird populations of North Dakota projected if CRP land would revert to cultivation. Of 18 species that were common in CRP or crop fields or...

We describe efforts to obtain access for research to 81 wetland basins on 69 farms in four zones of the Prairie Pothole Region of North Dakota, South Dakota, and Minnesota. Access was obtained to 54% of the farms in areas where land was intensively cropped and 87% of farms in areas of low cropping intensity. On average, 1.35 operators had to be contacted and 1.70 interviews were required...