Publications

The patterns of selection by wolves (Canis lupus) preying on moose (Alces alces), caribou (Rangifer tarandus), and Dall sheep (Ovis dalli) in Denali National Park and Preserve, Alaska were studied from 1986 through early 1992. Wolves and their prey are legally protected or relatively unharvested in most of the area, and wolf numbers doubled during the study. Based on remains of 294 moose...

The study investigated the utility of Landsat TM data applied to produce geo-referenced habitat maps for two study areas (Toledo and Stann Creek). Locational and non-site-specific map accuracy was evaluated by stratified random sampling and statistical analysis of satellite classification (SCR) versus air photo interpretation results (PIR) for the overall classification and individual...

The use of the Cormack- Jolly-Seber model under a standard sampling scheme of one sample per time period, when the Jolly-Seber assumption that all emigration is permanent does not hold, leads to the confounding of temporary emigration probabilities with capture probabilities. This biases the estimates of capture probability when temporary emigration is a completely random process, and...

Faced with the problem of habitat loss and with the need to preserve the remaining components of the original avian biodiversity in neotropical regions such as Los Tuxtlas, it is imperative to determine how the neotropical migrant bird species have responded to the anthropogenic alterations of their natural habitats. To provide data in this direction, we censused neotropical migrant...

Under the pressure of increasing human populations and expanding demands for food and fiber, native tropical and temperate habitats are becoming more restricted, and populations of many resident and migratory birds are declining. Mist net surveys of 111 forest and agricultural sites in Mexico, Belize, and Guatemala show that some migratory species use a wide variety of habitats during...

North American Breeding Bird Survey data indicated a general decline in Loggerhead Shrike (Lanius ludovicianus) populations during 1966-1993. At the continental level, shrikes declined at an average rate of 2.9% per year. Average rates of regional declines varied from 2.5-3.4% annually. These declines were prevalent in most states, provinces, and physiographic strata. Only the Edwards...

No abstract available.

There are many different types of contaminants present in the environment ranging from synthetic chemicals, which would not be present in the environment without man's intervention, to trace metals that are required for life. Concerns range from possible harmful effects on flora and fauna to possible harm to humans consuming such organisms. The complete chemical analysis for all possible

Although the front-fanged venom delivery system of the Elapidae is believed to be derived from an aglyphous or opisthoglyphous colubroid ancestor, opinion is divided as to the end of the maxilla on which the proteroglyph fang originated. This study was undertaken to determine whether the evolutionary precursor of the proteroglyph fang was (a) a grooved posterior fang which migrated...

The gray wolf once inhabited a wide variety of habitats throughout most of the northern hemisphere north of 20°N latitude. Because the animal preyed on livestock and competed with humans for wild prey, it was extirpated from much of its range outside of wilderness areas. Environmental awareness in the late 1960s brought for the wolf legal protection, increased research, and favorable...

Breeding Bird Surveys (BBS), which are widely used to monitor trends in avian populations (e.g. Robbins et al. 1989, Sauer and Droege 1993), are conducted along roads but are used to infer changes in regionwide populations. Such inferences may be inaccurate if trends in habitat along roads differ from regionwide trends. For example, if forest cover regionwide remained constant but forest...

Waterfowl and passerines in northern Idaho in 1987 had high levels of lead in their blood and tissues that originated primarily from mining and smelting activities. Four Canada geese (Branta canadensis) and one common goldeneye (Bucephala clangula) found dead contained 8 to 38 μg/g (wet mass) of lead in their livers. These levels exceed the lower lethal limit of 5 μg/g in experimental...