Publications

The capability to understand the nutritional ecology of free-ranging bears has increased dramatically in the last 20 years. Advancements have occurred because (1) managers and biologists recognized the need to link habitat quality, productivity, and variability with bear movements, home ranges, and demographic parameters like reproductive output, survival, and population growth, and (2) several re

Salmon (Oncorhynchuss pp.) are an important resource for terrestrial wildlife. However, the salmon requirements of wildlife populations and the role wildlife play in nutrient transport across ecosystems are largely ignored in salmon and habitat management. Any activity that reduces the availability of or access to salmon by wildlife may adversely affect wildlife populations and, potentially, ecosy

In January 2004, two natural avalanches (destructive class 3) derailed a freight train in John F. Stevens Canyon, on the southern boundary of Glacier National Park. The railroad tracks were closed for 29 hours due to cleanup and lingering avalanche hazard, backing up 112km of trains and shutting down Amtrak’s passenger service. The incident marked the fourth time in three winters that natural aval

The National Park Service of the United States has 388 designated protected areas and parks that include historic and cultural sites as well as ‘natural resource’ parks set aside for their unique and outstanding natural features. Early efforts to create parks were focused on areas of beauty or unusual features but later efforts increasingly aimed to protect biodiversity and intact ecosystems. Prot

The contents of this Annual Report summarize results of monitoring and research from the 2003 field season. The report also contains a summary of nuisance grizzly bear (Ursus arctos horribilis) management actions. The study team continues to work on issues associated with counts of unduplicated females with cubs-of-the-year (COY). These counts are used to establish a minimum population size, which

The annual spring opening of the Going-to-the-Sun Road in Glacier National Park presents a unique avalanche forecasting challenge. The highway traverses dozens of avalanche paths mid-track in a 23-kilometer section that crosses the Continental Divide. Workers removing seasonal snow and avalanche debris are exposed to paths that can produce avalanches of destructive class 4. The starting zones for

 Wildlife ecologists often use the Kaplan-Meier procedure or Cox proportional hazards model to estimate survival rates, distributions, and magnitude of risk factors. The Andersen-Gill formulation (A-G) of the Cox proportional hazards model has seen limited application to mark-resight data but has a number of advantages, including the ability to accommodate left-censored data, time-varying covariat

The populations of the ecologically dominant ungulates in the Serengeti ecosystem (zebra, wildebeest and buffalo) have shown markedly different trends since the 1960s: the two ruminants both irrupted after the elimination of rinderpest in 1960, while the zebras have remained stable. The ruminants are resource limited (though parts of the buffalo population have been limited by poaching since the 1

Climate change and ecological change go hand in hand. Because we value our ecological environment, any change has the potential to be a problem. Geographers have been drawn to this challenge, and have been successful in addressing it, because the primary ecological response to climate changes in the past — the waxing and waning of the great ice sheets over the past 2 million years – was the changi

We examined the distribution and home range characteristics of moose (Alces alces) and white-tailed deer (Odocoileus virginianus) at Voyageurs National Park, Minnesota. Pellet count transects revealed low densities of moose and higher densities of white-tailed deer, and provided evidence of partial spatial segregation between moose and white-tailed deer possibly due to habitat heterogeneity. Ther

Spawning cutthroat trout (Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears (Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed a method to estimate the amount of cutthroat trout ingested by grizzly bears living in the Yellowstone Lake area. The method utilized (i) the relatively high, naturally occurring concentr

Changes in age-specific reproductive rates can have important implications for managing populations, but the number of female brown (grizzly) bears (Ursus arctos) observed in any one study is usually inadequate to quantify such patterns, especially for older females and in hunted areas. We examined patterns of reproductive maturation and senescence in female brown bears by combining data from 20 s