The San Luis Valley and associated underlying basin of south-central Colorado and north-central New Mexico is the largest structural and hydrologic basin of the Rio Grande Rift and fluvial system. The surrounding San Juan and Sangre de Cristo Mountains reveal evidence of widespread volcanism and tra

In recent decades, intense droughts, insect outbreaks, and wildfires have led to decreasing tree growth and increasing mortality in many temperate forests. We compared annual tree-ring width data from 1,097 populations in the coterminous United States to climate data and evaluated site-specific tree

The results suggest that yearling yellow-bellied marmots are more important for maintaining social cohesion than has previously been recognized, and that marmot colonies are largely organized based on age group and kinship.

The link between reproductive and vegetative ecology of flowering plants is rarely explored, despite its importance for understanding population processes and fitness. This link can be studied by using experimental or natural variation in seed input to the soil to assess how reproductive success aff

Spatio-temporal patterns of snowmelt and flowering times affect fruiting success in Erythronium grandiflorum Pursh (Liliaceae) in subalpine western Colorado, USA. From 1990 to 1995, I measured the consistency across years of snowmelt patterns and flowering times along a permanent transect. In most y

It is demonstrated how earlier emergence from hibernation and earlier weaning of young has led to a longer growing season and larger body masses before hibernation, and this helps explain how a shift in phenology can cause simultaneous phenotypic and demographic changes.

Predators can have remote effects on prey populations that are connected by migration (i.e. prey metapopulations) because predator-mediated changes in prey behavior and abundance effectively transmit the impact of predators into predator-free prey populations. Behavioral changes in prey that might g

Mammalian sociality varies both within and between species. We developed a trait-based method to quantify sociality in a continuous way to study the adaptive utility and evolution of male social behavior. The metric is based on 3 key traits—mutual tolerance, collaboration, and partner preference; ma

Previous studies have demonstrated that bird song is influenced by infection. We investigated how mounting an immune response by mountain white-crowned sparrows (Zonotrichia leucophrys oriantha) affects specific aspects of territorial song and behavior. We used song playback to simulate a territoria

Letter to Colorado Governor Bill Owens From Ralph E. Clark III April 20 2000

From: Greg Walcher (Executive Director of DNR) To: Senator Campbell (“The Honorable Ben Nighthorse Campbell) February 29th 2000

Laura Farris & David Schaller. US EPA Region 8. November 2000.

Bob Ewegen The Denver Post April 17th 2000