Publications

North Dakota is a major fall staging area for the Midcontinent Population of sandhill cranes (Grus canadensis), which is composed of three subspecies: the greater (G. c. tabida), Canadian (G. c. rowani), and lesser (G. c. canadensis). The number of cranes killed by hunters in North Dakota averaged 6,793 during 1990-94 seasons, ranking second highest among crane-hunting states. The...

No abstract available.

The Midcontinental population of sandhill cranes (Grus canadensis) has a large geographic range, contains nearly 500,000 birds, and is hunted in much of its range. The population includes three subspecies; the numbers of two of these are uncertain, and they should be afforded protection from hunting that would be detrimental to their population. The two subspecies of concern tend to...

No abstract available.

This seventh supplement after the publication of the 6th edition (1983) of the AOU Check-list of North American Birds includes taxonomic and nomenclatural changes adopted by the Committee on Classification and Nomenclature between 15 March 1995 and 15 March 1997. Because this will be the last supplement before the publication of the 7th edition of the Check-list, it also summarizes other...

The wealth of data generated from intensive study of the brown tree snake as a result of the need to control introduced populations of this pest species allow several important conclusions. First, that the snakes on Guam are extraordinary in terms of their absolute abundance and in terms of their ability to exploit a broad prey base. Our data suggest an exceptionally high reproductive...

The presence of transient animals, common enough in natural populations, invalidates the estimation of survival by traditional capture- recapture (CR) models designed for the study of residents only. Also, the study of transit is interesting in itself. We thus develop here a class of CR models to describe the presence of transients. In order to assess the merits of this approach we...

Adult eared grebes exhibit threefold fluctuation in body mass and up to a fivefold variation in liver weight during the course of their annual breeding and migratory cycle. Concentrations of 20 metals or metalloids were quantified in the liver from eared grebes obtained at three phases of their annual cycle: newly arrived migrants (July-August-September), staging (October-November), and...

Larval blacklegged ticks, Ixodes scapularis, were collected from white-footed mice, Peromyscus leucopus, on Prudence Island (where Microtus pennsylavanicus were not captured) and from meadow voles, M. pennsylvanicus, on Patience Island (where P. leucopus was absent) in Narragansett Bay, Rhode Island from June to October 1992. Ixodes scapularis larvae were also collected by flagging in...

An epizootic of eastern equine encephalitis (EEE) at the Patuxent Wildlife Research Center (PWRC), Laurel, Maryland (USA), in 1989 provided an opportunity to determine if EEE immunization protected whooping cranes (Grus americana). Based on seroconversion of 31% of sympatric hatch-year sandhill cranes, Grus canadensis, and a previous 35% case fatality rate in whooping cranes, 17 (37%) of...

During 1993-94 and 1994-95, the amount of watershield (Brasenia schreberi) in selected Maryland wetlands was determined to see if a relationship existed between the amount of watershield on a wetland and the number of ring-necked ducks (Aythya collaris) observed on that wetland. Data were collected for two years from eight different wetlands on the Patuxent Research Refuge in Laurel...

An estimated 80% of redheads (Aythya americana) winter on the Laguna Madre of southern Texas and Mexico. Because there have been profound changes in the Laguna Madre over the past three decades and the area is facing increasing industrial and recreational development, we studied the winter distribution and habitat requirements of redheads during two winters (1987-1988 and 1988-1989) on...