Social behavior of yellow-bellied marmots was observed for three years in colonies where kinship was known and for one year in a high elevation colony where harems were contiguous, indicating that reproductive strategies limit nepotism.

We examined the roles of floral scent and color in attracting bumblebees (Bombus spp.) to snapdragon flowers (Antirrhinum, Sonnet cultivar). Corolla color differences covaried with differences in floral scent emissions in two inbred lines of snapdragon. White-flowered plants emitted methyl cinnamate

• This research tested the hypothesis that experimental infrared warming will reduce photosynthesis for the evergreen shrub Artemisia tridentata and the subalpine, herbaceous Erythronium grandiflorum exposed to an in situ experimental freezing event during the spring snowmelt period. • Photosyntheti

Pollen discounting, a reduction in success as an outcross pollen parent as a result of selfing, can reduce or eliminate the reproductive advantage commonly attributed to selfing. Previous estimates of pollen discounting have been based on segregation analysis of progeny from open-pollinated plants.

To explore mechanistic constraints on the evolution of optimal phenotypes, we develop an optimality model for thermoregulation in Colias butterflies. The model identifies the thermoregulatory characteristics of butterflies that maximize time available for flight activity subject to an overheating co

Training in science, technology, engineering, and mathematics (STEM) is a top priority for driving economic growth and maintaining technological competitiveness. We propose that exposure to a rigorous research program as an undergraduate leads to success in a research STEM career. We compared the sc

Standard metabolic rates of both species are more thermally dependent than comparable values for lowland relatives and thermal sensitivity of physiological functions may have distinct advantages over thermally compensated rates in the short growing season and daily thermal fluctuations of the montan

Ecosystems at high elevations may be especially sensitive to global warming, because productivity is limited to a snow-free growing season, and warming is expected to cause earlier snowmelt. Here we report on vegetation responses to experimental warming in a subalpine meadow in the Colorado Rocky Mo

Parental environmental effects-or transgenerational plasticity-can influence an individual's phenotype or fitness yet remain underexplored in the context of global change. Using the perennial self-pollinating plant Boechera stricta, we explored the effects of climate change on transgenerational and

In situ behavioral experiments were conducted in flow-through observation boxes in a Colorado and a New York stream to compare and contrast the cercal responses of Ephemerellidae and Baetidae mayflies to predaceous stoneflies. Ephemerella infrequens (Colorado) exhibited primarily a posture when touc

How does recent climate warming and climate variability alter fitness, phenotypic selection and evolution in natural populations? We combine biophysical, demographic and evolutionary models with recent climate data to address this question for the subalpine and alpine butterfly, Colias meadii , in t

Ecosystem carbon cycle feedbacks to climate change comprise one of the largest remaining sources of uncertainty in global model predictions of future climate. Both direct climate effects on carbon cycling and indirect effects via climate-induced shifts in species composition may alter ecosystem carb

Abstract The polymorphic phosphoglucomutase (PGM) and glucose-6-phosphate dehydrogenase (G6PD) loci have been studied in parallel to experimental work on the phosphoglucose isomerase (PGI) polymorphism in Colias butterflies. PGI, PGM and G6PD are also autosomal in Colias. PGM and G6PD are loosely li

There was no consistent relationship between measures of population density and concentrations of corticosteroids; when a significant relationship occurred, only 22-34% of the variation was explained.

Despite recent advances in biodemography and metapopulation ecology, we still have limited understanding of how local demographic parameters influence short- and long-term metapopulation dynamics. We used long-term data from 17 local populations, along with the recently developed methods of matrix m

Coalitions occur when multiple individuals cooperate against a common opponent or for a common goal. Coalition formation is a complex behavior, typically described in highly social and cognitively complex species. Surprisingly, we know little about the social and environmental factors that may selec

This study is the first to document the use of hydrodynamic cues by stream-dwelling predators for discrimination of prey from nonprey and provides a mechanism to explain selective predation by stoneflies on Baetis in nature.

Conservation of marmots, large ground-dwelling squirrels restricted to the northern hemisphere, was impacted by direct human activity through hunting or modifying ecosystem dynamics. Regulating human activities reduced the threat of extinction. Climate change, an indirect human impact, threatens mar

Small vertebrates were recovered from the matrix encasing specimens of giant sauropod dinosaurs (Supersaurus, Ultrasaurus, Dystylosaurus) collected from the “Dry Mesa” Quarry (Brushy Basin Member, Morrison Formation, western Colorado). Most of the remains appear to pertain to a single form of pterod