Publications

We quantified broad-scale patterns of species richness and species density (mean # species/km2) for native and non-indigenous plants, birds, and fishes in the continental USA and Hawaii. We hypothesized that the species density of native and non-indigenous taxa would generally decrease in northern latitudes and higher elevations following declines in potential evapotranspiration, mean...

Predation on black-footed ferrets (Mustela nigripes) is a potential problem at reintroduction sites, causing up to 95 percent of the documented mortality of ferrets. Strategies to reduce mortality due to predation can focus on preconditioning ferrets prior to reintroduction and/or managing predators of ferrets. Biologists have tried three general strategies to control predators at...

Black-footed ferrets (Mustela nigripes) are highly dependent on prairie dogs (Cynomys spp.) as prey, and prairie dog colonies are the only known habitats that sustain black-footed ferret populations. An existing model used extensively for evaluating black-footed ferret reintroduction habitat defined complexes by interconnecting colonies with 7-km line segments. Although the 7-km complex...

A successful captive breeding program for highly endangered black-footed ferrets (Mustela nigripes) has resulted in surplus animals that have been released at multiple sites since 1991. Because reproductive output of captive ferrets declines after several years, many adult ferrets must be removed from captive breeding facilities annually to keep total production high. Adults are...

We used radio-telemetry data (28,560 positional fixes) collected on 153 black-footed ferrets (Mustela nigripes) to (1) reexamine the assumed obligate relationship of these ferrets to prairie dogs (Cynomys spp.), (2) investigate habitat preferences of ferrets at a small scale (1 year (P = 0.048). Also, preference was stronger for wild-born young ferrets than for young captive-born ferrets...

No abstract available.

The bonytail and razorback sucker are two of four endangered mainstem fishes found in the Colorado River. Unlike the Colorado pikeminnow and humpback chub, wild populations of the bonytail and razorback sucker are either extirpated from the mainstem river or are nearly so. Agencies are aggressively stocking these fish and while repatriated fish spawn, their young are rapidly eaten by...

The National Institute of Invasive Species Science (www.NIISS.org) is a consortium of governmental and nongovernmental partners, led by the U.S. Geological Survey (USGS), whose aim is to provide reliable information and advanced decision support tools for documenting, understanding, predicting, assessing, and addressing the threat of invasive species in the United States. The Institute...

We estimated abundance quantiles of redband trout Oncorhynchus mykiss gairdneri relative to five site-specific habitat variables (stream shading, bank cover, bank stability, fine sediment in the stream substrate, and cover for adults) and one landscape variable (distance from stream headwaters) on 30 streams in southwestern Idaho during 1993–1998. In addition, the five site-specific...

Managing rivers and streams to maintain healthy aquatic ecosystems is a challenge for resource managers across the country. Demand for competing uses of water resources grows with escalating development, increasing recreational use, and the vagaries of climate and weather. For many species of concern, instream flow and associated water quality are critical for survival. Balancing...

No abstract available.

No abstract available.