A key characteristic of host–parasite interactions is the theft of host nutrients by the parasite, yet we lack a general framework for understanding and predicting the interplay of host and parasite nutrition that applies across biological levels of organization. The elemental nutrients (C, N, P, Fe

Abstract Terrestrial and aquatic elemental cycles are tightly linked in upland fluvial networks. Biotic and abiotic mineral weathering, microbially mediated degradation of organic matter, and anthropogenic influences all result in the movement of solutes (e.g., carbon, metals, and nutrients) through

A fluorescent-dye technique permitted the mating success of male checkerspot butterflies aggregating on a ridge to be compared with that of males on the slope below. Unexpectedly, the males on the ridge had about one-half the mating success of those on the slope. We suggest that formation of this an

The effect of grazing on the hydrology of salt-desert type rangeland has been studied near Grand Junction, Colorado for the past 14 years. Measurements of precipitation, runoff, erosion, and vegetation have been made in four pairs of watersheds. One of each pair has been grazed by cattle and sheep a

Abstract Linking pattern to process across spatial and temporal scales has been a key goal of the field of biogeography. In January 2017, the 8th biennial conference of the International Biogeography Society sponsored a symposium on Building up biogeography—process to pattern that aimed to review pr

Background: Trait evolution and plasticity are expected to interactively influence responses to climate change, but rapid changes in and increased variability of temperature may limit evolutionary responses. We use historical specimens to document changes in the size and thermoregulatory traits of a

Aims resembled those of the previously removed dominant species. Decades of empirical work have demonstrated how dominant plant Ecosystem productivity generally increased with N addition: soil species and nitrogen fertilization can influence the structure and carbon efflux was ~50% greater when eith

Social relationships are composed of both positive (affiliative) and negative (agonistic) interactions, representing opposing effects. Social network theory predicts that positive relationships should be transitive; thus, the friend of a friend is more likely to be a friend. Further, when considerin

The adult demography of a population of Speyeria mormonia (Lepidoptera: Nymphalidae) near Gothic, Colorado USA was studied for four years. Values of demographic parameters, including survival, dispersal and sex ratio, varied yearly, without major changes in density. Shift in sex ratio with constant

Group size effects, whereby animals allocate less time to antipredator vigilance as a function of increasing group sizes are widely reported in many taxa, but group size is but one of many social attributes that could increase a individual’s sense of security. Indeed, meta-analyses suggest that grou

ABSTRACT A nearly complete skull of Eutretauranosuchus delfsi was uncovered at the upper Jurassic Dry Mesa Dinosaur Quarry in the Brushy Basin Member of the Morrison Formation in western Colorado. It permits an expanded description of the taxon. Like the holotype, from Canyon City, Colorado, the Dry

AbstractSoil respiration is a primary component of the terrestrial carbon cycle. However, predicting the response of soil respiration to climate change remains a challenge due to the complex interactions between environmental drivers, especially plant phenology, temperature, and soil moisture. In th

AbstractSenescence is a highly variable process that comprises both age‐dependent and state‐dependent components and can be greatly affected by environmental conditions. However, few studies have quantified the magnitude of age‐dependent and state‐dependent senescence in key life‐history traits acro

In the headwater catchments of the Rocky Mountains, plant productivity and its dynamics are largely dependent upon water availability, which is influenced by changing snowmelt dynamics associated with climate change. Understanding and quantifying the interactions between snow, plants and soil moistu

Movement uses resources that may otherwise be allocated to somatic maintenance or reproduction. How does increased energy expenditure affect resource allocation? Using the butterfly Speyeria mormonia, we tested whether experimentally increased flight affects fecundity, lifespan or flight capacity. W

AbstractAlarm calling is common in many species. A prevalent assumption is that calling puts the vocalizing individual at increased risk of predation. If calling is indeed costly, we need special explanations for its evolution and maintenance. In some, but not all species, callers vocalize away from

Events that follow pollination, such as pollen-tube growth and seed maturation, comprise an important phase of angiosperm reproduction. Differential success during this "postpollination" phase may represent phenotypic selection, including sexual selection, or interaction between parents caused, for

Energy intake, daily energy expenditure (DEE), and energy available for production were determined for yellow-bellied marmots (Marmota flaviventris) at three study sites in the Elk Mountains of southwestern Colorado. Energy intake, estimated from tritiated-water turnover rates and the water and ener