Summary1. In the face of human‐induced declines in the abundance of common species, ecologists have become interested in quantifying how changes in density affect rates of biophysical processes, hence ecosystem function. We manipulated the density of a dominant detritivore (the cased caddisfly, Limn

Experimental tools that enable manipulations of organisms at larger scales allow for comparisons of processes across multiple spatial scales and expand our ability to make predictions about ecological processes. We performed reach scale (i.e., 50 m2) manipulations of invertebrate communities in stre

We monitored the demographics of the salamander Ambystoma tigrinum nebulosum as part of a community-wide study on the effects of acidification in sub-alpine (elevation 3600 m) ponds in central Colorado. A decline in A. t. nebulosum at this site from 1982 to 1988 has been hypothesized to result from

Abstract. Meteorological forcing plays a critical role in accurately simulating the watershed hydrological cycle. With the advancement of high-performance computing and the development of integrated watershed models, simulating the watershed hydrological cycle at high temporal (hourly to daily) and

Brink (1982) characterizes the distribution of standing crop of nectar for Delphinium nelsonii as bonanzablank, based on comparison with a Poisson, but this work disagrees with the use of the Poisson and the resulting conclusions.

In harem-polygynous societies, body condition is often correlated with dominance rank. However, the consequences of dominance are less clear. High-ranking males do not inevitably have the highest reproductive success, especially in systems where females mate with multiple males. In such societies, w

During March 1986, several airborne and ground-based silver iodide (AgI) seeding experiments were conducted over the Grand Mesa, Colorado, during a three-day period of northerly flow and shallow orographic cloud. While little natural snowfall was observed during these experiments, supercooled liquid

The butterfly Pieris napi (L.) and relatives exemplify recently evolving taxa, exhibiting variation that makes their evolutionary dynamics interesting, but their systematics difficult. Wing-pattern characters commonly used to distinguish these Holarctic insects display both genetic polymorphism and

Mirror-image stimulation (MIS) was used to determine the individual behavioral phenotypes of 90 adult, 132 yearling, and 135 young yellow-bellied marmots (Marmota flaviventris). Linear typal analysis (LTA) was used to group individuals based on similarities in their MIS scores. Principal component a

Abstract The North American Monsoon occurs July–September in the central Rocky Mountains bringing significant rainfall to Colorado River headwater basins. This rain may buffer streamflow deficiencies caused by reductions in snow accumulation. Using a data‐modeling framework, we explore the importanc

Experiments were conducted to determine whether overlap between microhabitat preferences and activity periodicities of four mayfly species and their stonefly predators could explain species-specific differences in predator-prey encounter frequencies. Preferences for rock type (slate or granite), flo

U/Pb zircon/titanite geochronology, in situ monazite geochronology, and 40Ar/39Ar thermochronology provide an unusually complete data set for reconstructing the tectonic history of Proterozoic rocks exposed in the Black Canyon, Gunnison, Colorado. These new geochronologic data record three protracte

The observations support the hypothesis that the phagotrophic euglenoids arose from a bondonid ancestor and gave rise to the phototrophs by chloroplast acquisition.

A tomographic inversion of teleseismic shear wave delays has been performed using data collected in the 1992 Program for Array Seismic Studies of the Continental Lithosphere Rocky Mountain Front experiment. The shear wave residuals used as data were corrected for known crustal, sediment and topograp

Climate change is rapidly driving global biodiversity declines. How wetland macroinvertebrate assemblages are responding is unclear, a concern given their vital function in these ecosystems. Using a data set from 769 minimally impacted depressional wetlands across the globe (467 temporary and 302 pe

Time budgets for 17 behaviors were analyzed for cohort, day-period, season- period and interactions among the main effects for three colonies of yellowbellied marmots in the Upper East River Valley in western Colorado. These effects explained up to 79% of the variation in the behaviors. Marmots allo

I implanted radio transmitters in 183 yellow-bellied marmots (Marmota flaviventris); transmitters were replaced -<6 times in 73 animals, for 300 surgeries. Surgical procedures were simple, effective, and largely trouble-free. Survival 30 days later was -98%, and growth rates (21 g/day) were the same