1. We revisited bumble bee survey data collected by Pyke in 1974 (Pyke, Ecology , 63 , 555–573, 1982) to evaluate seasonal changes in abundances of bumble bees and their floral resources, diel patterns of bumble bee activity, and elevation effects on plant and bumble bee phenology. 2. Bumble bee abu

Variation in flowering plant density can have conflicting effects on pollination and seed production. Dense flower patches may attract more pollinators, but flowers in those patches may also compete for pollinator visits and abiotic resources. We examined how natural and experimental conspecific flo

Understanding the causes and limits of population divergence in phenotypic traits is a fundamental aim of evolutionary biology, with the potential to yield predictions of adaptation to environmental change. Reciprocal transplant experiments and the evaluation of optimality models suggest that local

It is concluded that predation alone cannot explain variation in population dynamics of either mayfly species; and the relative importance of predation is species- and environment-specific compared to non-predatory losses, such as other agents of mortality and non-consumptive effects of predators.

Recent research shows that fungal exploitation of pollinators has the potential to affect floral evolution, pollination ecology, plant life history traits, as well as disease-transmission dynamics and fungal evolution.

Dispersal among spatially subdivided populations and variability in local habitat patch quality can strongly affect local and regional population dynamics. A metapopulation of mayflies (Callibaetis ferrugineus hageni) was studied in which larvae developed in beaver ponds and emerged to the terrestri

• Premise of the study: Plants are flowering earlier in response to climate change. However, substantial interannual variation in phenology may make it difficult to discern and compare long‐term trends. In addition to providing insight on data requirements for discerning such trends, phenological sh

Abstract Groundwater interactions with mountain streams are often simplified in model projections, potentially leading to inaccurate estimates of streamflow response to climate change. Here, using a high-resolution, integrated hydrological model extending 400 m into the subsurface, we find groundwat

Based on previous studies, extreme ( 99%) self‐sterility in scarlet gilia (Ipomopsis aggregata) appears to be involved in late‐acting ovarian self‐incompatibility (OSI). Here, we confirm this suggestion by comparing structural events that follow from cross‐ vs. self‐pollinations of I. aggregata. Gro

Results of this study suggest that the wing whistle of male broad-tailed hummingbirds is important in maintenance of courting territories and hence in reproductive success.

The hypothesis that a sychrony of the time of seed dispersal and the period when most ants (mutualists) and least rodents (predators) are active would be advantageous to the plant species is discussed.

Phenotypic manipulations of two or more traits in combination provide a direct way of testing for selection of floral trait associations. Such experiments will be particularly valuable if rooted in hypotheses about differences between types of pollinators and tied to a proposed evolutionary history.

By sampling standing crop of nectar in a D. nelsonii population during periods of both high and low bumblebee abundance evidence was gathered indicating that hot and cold spots are caused by bumblebees.

Climate change is affecting both the timing of life history events and the spatial distributions of many species, including plants and pollinators. Shifts in phenology and range affect not only individual plant and pollinator species but also interactions among them, with possible negative consequen

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

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

• 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

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

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