It is hypothesized that nectar-collecting bumblebees will be found to forage in ways that maximize their net rate of energy intake, and the manner in which they move from one flower to another within inflorescence is focused on.

The total number of viable, undamaged seeds released by a plant provides an estimate of female reproductive success (RS). I outline a method for analyzing pollinator-mediated selection based on partitioning female RS into four multiplicative components: number of flowers, pollen received per flower,

Climate change is expected to alter patterns of species co‐occurrence, in both space and time. Species‐specific shifts in reproductive phenology may alter the assemblages of plant species in flower at any given time during the growing season. Temporal overlap in the flowering periods (co‐flowering)

Genetic variances, heritabilities, and genetic correlations of floral traits were measured in the monocarpic perennial Ipomopsis aggregata (Polemoniaceae). A paternal half-sib design was employed to generate seeds in each of four years, and seeds were planted back in the field near the parental site

Abstract Pollen presentation theory (PPT) allows for a re‐examination of some classic themes in pollination biology. Here, we outline its implications in the context of bee‐ and bird‐adapted species of Penstemon and Keckiella (Scrophulariaceae). PPT models the optimal schedule of pollen presentation

This work focused on the individually distinctive calls of yellow-bellied marmots, Marmota flaviventris, to describe attributes of individuals encoded in calls, and found significant potential information about identity, age and sex encode in calls.

We have elaborated a model describing the development of polygynous mating systems. The bases of the model are measures of fertility and survival of adult females and their offspring, respectively, as functions of increasing harem size. Our data indicate that an adult female makes her greatest contr

Two distinct communities exist in a series of small subalpine ponds on Galena Mountain, Colorado, at 3,400 m. In the deep ponds, two predators, the culicid larva Chaoborus and the axolotl Ambystoma tigrinum, coexist with two small herbivores, the copepod Diaptomus coloradensis and the cladoceran Dap

It was hypothesized that the local geographic distributions of bumblebees near Crested Butte, Colorado and the community patterns exhibited by these bumblebees are the products of competition for plants. To evaluate this hypothesis several transects were established and at regular intervals througho

AbstractClimatic change is predicted to alter rates of soil respiration and assimilation of carbon by plants. Net loss of carbon from ecosystems would form a positive feedback enhancing anthropogenic global warming. We tested the effect of increased heat input, one of the most certain impacts of glo

Plant populations vary in density both naturally and as a consequence of anthropogenic impacts. Density in turn can influence pollination by animals. For example, plants in dense populations might enjoy more frequent visitation if pollinators forage most efficiently in such populations. We explored

SignificanceThe evolution of herbivory in animals is rare but has resulted in major adaptive radiations. Its rarity suggests that there are barriers to colonization of plants. Behavioral adaptations, involving host plant finding, are likely the first to evolve during the transition to herbivory. A r

Unlike individually distinctive contact calls, or calls that aid in the recognition of young by their parents, the function or functions of individually distinctive alarm calls is less obvious. We conducted three experiments to study the importance of caller reliability in explaining individual-disc

The element selenium (Se) is both essential and toxic for most life forms, with a narrow margin between deficiency and toxicity. Phytotechnologies using plants and their associated microbes can address both of these problems. To prevent Se toxicity due to excess environmental Se, plants may be used

Current understanding of reproduction for animal-pollinated plant species is based on the premise that traits of flowers and inflorescences influence reproductive success by affecting pollinator behavior. This implies that within-population variation in such traits should affect reproductive success

AbstractMacroecology seeks to understand broad‐scale patterns in the diversity and abundance of organisms, but macroecologists typically study aboveground macroorganisms. Belowground organisms regulate numerous ecosystem functions, yet we lack understanding of what drives their diversity. Here, we e

Many alpine and subalpine plant species exhibit phenological advancements in association with earlier snowmelt. While the phenology of some plant species does not advance beyond a threshold snowmelt date, the prevalence of such threshold phenological responses within plant communities is largely unk

Natural hybrid zones between related species illustrate processes that contribute to genetic differentiation and species formation. A common viewpoint is that hybrids are essentially unfit, but they exist in a stable tension zone where selection against them is balanced by gene flow between the pare