AbstractAlthough bedrock weathering strongly influences water quality and global carbon and nitrogen budgets, the weathering depths and rates within subsurface are not well understood nor predictable. Determination of both porewater chemistry and subsurface water flow are needed in order to develop

The microdistribution of adult subalpine butterflies was examined in relation to several components of the mountain meadow flora in Gunnison County, Colorado. With the exception of two small, sedentary species, there was no significant correlation between the microdistribution of the butterflies and

Two different mechanisms can result in multiple paternity within fruits: deposition of a mixed pollen load due to carryover of pollen from flower to flower and multiple pollinator visits in close succession. I investigated the extent of multiple paternity within fruits of Ipompsis aggregata containi

AbstractRelatively little is known about the effects of specific parasites on sexually selected behavioral traits. We subjected free‐living mountain white‐crowned sparrows (Zonotrichia leucophrys oriantha) to a playback experiment to identify the effect of hemosporidian parasites on potentially sexu

Multiple environmental factors may act synergistically to influence demographic characteristics, and ultimately the dynamics, of biological populations. Using prospective and retrospective analyses of demographic data from a 40-year study of individually marked animals, we investigated the demograph

SummaryAlthough secondary metabolites are prevalent in floral nectar, the ecological consequences for pollinators and pollination remain relatively unexplored. While often deterrent to pollinators at high concentrations, secondary metabolite concentrations in nectar tend to be much lower than second

A core of varved lake sediments from Devlins Park, Front Range, Colorado, has yielded a radiocarbon-dated pollen record of environments during the last major advance of Pinedale ice. The downstream end of Devlins Park was dammed by Pinedale ice from 22,400 to 12,180 BP, creating the lake. The pollen

“Pollination syndromes” are specific combinations of floral traits that are proposed to evolve convergently across angiosperm lineages in response to different types of animal pollinators. In spite of their long history, pollination syndromes have not been tested adequately–they rarely have been exa

Differences in foraging behavior observed on two plant species with similar floral and inflorescence structures increase the neighborhood size for nectar producing species and make it increasingly unlikely that random drift will be a dominant mode of evolution in populations of these species.

Summary1. Populations of a number of sub‐tropical stream insect species have been found to show unexpected patterns of genetic variation, with more differences between samples from the same stream than between whole streams or between subcatchments. Many samples also showed deviations from Hardy–Wei

It is suggested that during the summer when marmots are not hibernating and are actively feeding, brain insulin levels may play a role in regulating food intake.

This study addresses the field-scale architecture and dimensions of fluvial deposits of the lower Williams Fork Formation through analysis of outcrops in Coal Canyon, Piceance Basin, Colorado. The lower Williams Fork Formation primarily consists of mud rock with numerous isolated, lenticular to chan

Evidence is presented in support of the suggestion that a hovering bird is able to move between flowers more quickly than one that is perching, however, this advantage to hovering may be offset by the higher energetic costs of hovering as compared with perching.

The dispersal was associated with changes in home ranges and with the avoidance of dominant animals by subordinate animals, and females moved from being concentrated in the centre of the colony to being more widely dispersed during the vernal period.

Heterogeneous distributions of resources and organisms are characteristic of most ecosystems, but empirical understanding of the causes and consequences of heterogeneity is limited. We investigated whether predatory fish influenced the heterogeneity (spatial variability) of resources (algae) by modi

Our grasp of biodiversity is fine-tuned through the process of revisionary taxonomy. If species do exist in nature and can be discovered with available techniques, then we expect these revisions to converge on broadly shared interpretations of species. But for the primarily arctic bumblebees of the

AbstractWarm temperatures are required for insect flight. Consequently, warming could benefit many high‐latitude and high‐altitude insects by increasing opportunities for foraging or oviposition. However, warming can also alter species interactions, including interactions with natural enemies, makin

Animals generally allocate some time during foraging to detecting predators. We used a combination of observations and an experiment to examine how vegetation height and peripheral obstructions influence vigilance by foraging yellow-bellied marmots ( I Marmota flaviventris /I ). First, we analyzed a

It is hypothesized that the average rate of nectar production per flower for a population of plants is such than an individual plant which possesses this rate has maximum fitness (i.e., is optimal), and predictions concerning nectarProduction in scarlet gilia, a hummingbird pollinated plant are deve