Publications

Capture-recapture methods are widely used to estimate population parameters of free-ranging animals. Closed-population capture-recapture models, which assume there are no additions to or losses from the population over the period of study (i.e., the closure assumption), are preferred for population estimation over the open-population models, which do not assume closure, because...

Boreal toads (Bufo b. boreas) are widely distributed over much of the mountainous western United States. Populations in the Southern Rocky Mountains suffered extensive declines in the late 1970s through early 1980s (Carey, 1993). At the time, these mass mortalities were thought to be associated with a bacterial infection (Carey, 1993). Although the few populations that survived the mass...

No abstract available.

Two populations of boreal toads (Bufo boreas) experienced drastic declines in abundance in the late 1990s. Evidence supported the hypothesis of disease (the chytrid fungus, Batrachochytrium dendrobatidis) as the cause of these declines, but other hypotheses had not been evaluated. We used an 11-year capture–recapture data set to evaluate weather and disease as causes of these declines...

Water from many of California's coastal rivers has been used for a wide variety of development ventures, including major agricultural diversions, hydropower generation, and contaminant assimilation from industry, agriculture and logging. Anthropogenic impacts often degrade water quality and decrease the quantity and quality of aquatic habitat. Reallocating streamflow away from uses that...

Understanding the influences of habitat fragmentation on vertebrate populations is essential for the protection and ecological restoration of strategic sites for native species. We examined the effects of prairie fragmentation on avian reproductive success using artificial and natural nests on 26 randomly selected, privately owned patches of shortgrass prairie ranging in size from 7 to...

Elevated water temperatures have been implicated as a factor limiting the recovery of anadromous salmonids in the Klamath River basin. This article reviews evidence of a multidecade trend of increasing temperatures in the lower main-stem Klamath River above the ocean and, based on model simulations, finds a high probability that water temperature has been increasing by approximately 0.5...

In June 2004 the U.S. Department of Agriculture’s Farm Service Agency (FSA), with support from the U.S. Geological Survey (USGS), held a three-day symposium on the Conservation Reserve Program (CRP) in Fort Collins, Colorado. These proceedings contain papers by most of those who made presentations at the symposium, but some were unable to provide written papers. This shortcoming has been...

Historically, the Colorado River was one of the most formidable rivers in the world. Each spring, melting snow from the mountains scoured the desert landscape moving millions of tons of sediment to the sea. The Grand Canyon lays testament to its erosive nature. Summer heat would bring seasonal droughts, reducing the river to a trickle impacting humans, animals, and fish. Isolated by high...

We compared over-winter body temperature (Tb) patterns for more than 6 months in adult (> 1 year) black-tailed (Cynomys ludovicianus) and Utah (C. parvidens) prairie dogs from colonies located along gradients of elevation in northern Colorado and southern Utah. In general, black-tailed prairie dogs entered torpor facultatively during winter, whereas Utah prairie dogs hibernated...

Morphological intermediates between Tamarix ramosissima or T. chinensis (saltcedars) and T. aphylla (athel) were found recently in three locations in the southwestern USA, and were assumed to be hybrids or a previously unreported species. We sequenced chloroplast and nuclear DNA from putative parental and hybrid morphotypes and hybrid status of morphological intermediates was supported

No abstract available.