Climate in subalpine meadows of the Rocky growing season drought conditions. Manipulating Mountains can be characterized by an early (fore- the strength of the foresummer drought by watering summer) drought that occurs after snowmelt (May) revealed that the timing of growing season pre- and lasts un

Climate warming-induced plant species loss is likely to be nonrandom and based on species-specific susceptibility to changing climate. We examined the ecological consequences of losing shallow-rooted forbs, a group of species we predict to be adversely affected by climate change based on their respo

We investigated the effects of prey size and type (sedentary vs mobile) on prey preference in a predaceous stonefly, based on choice experiments and observations of the predator-prey interaction. We presented three size classes of black fly larvae (Prosimulium) to various sizes of the perlid stonefl

A. tigrinum larvae from two ponds in the Elk Mountains of western Colorado were found to eat a wide variety of foods, including a total of 42 classes, mostly of various littoral, benthic, and planktonic arthropods. Most common animals (between 0.5 and 20 mm in length) in these ponds were eaten in pr

Spatiotemporal variation in age-specific survival rates can profoundly influence population dynamics, but few studies of vertebrates have thoroughly investigated both spatial and temporal variability in age-specific survival rates. We used 28 years (1976-2003) of capture-mark-recapture (CMR) data fr

The slow-fast continuum is a commonly used framework to describe variation in life-history strategies across species. Individual life histories have also been assumed to follow a similar pattern, especially in the pace-of-life syndrome literature. However, whether a slow-fast continuum commonly expl

AbstractGlobal models project impending climate changes that could significantly alter plant species composition in ecosystems. Climate manipulation experiments provide an opportunity to investigate such effects. Here we describe and apply a method for extracting the age‐detrended growth rate of sag

Movements of Colorado squawfish Ptychocheilus lucius were studied by radio-tracking and recapturing tagged fish in the Green River basin of Colorado and Utah, 1980–1988. Of 153 fish tracked, 63% were highly mobile: 41% migrated to known spawning sites, 11% migrated to suspected spawning sites, and 1

Seed set in the perennial larkspur Delphinium nelsonii is greater in crosses between plants growing an intermediate distance apart than in shorter and longer crosses. Since crossing distance is an attribute of a specific combination of parents, its effect on seed set represents an interaction of the

This study addresses the field-scale architecture and static connectivity of fluvial sandstones of the lower Williams Fork Formation through analysis and reservoir modeling of analogous outcrop data from Coal Canyon, Piceance Basin, Colorado. The Upper Cretaceous lower Williams Fork Formation is a r

Abstract Understanding the time water takes as it moves from rain or snowmelt through the terrestrial system to arrive as stream discharge, or evapotranspiration (ET) is an important hydrologic quantity. We develop a Lagrangian particle tracking method to capture transient residence times from sourc

The circannual cycle of MR is suggested as the driving force underlying the cycles of food consumption and Bm in marmots, which corresponds well with observed differences in above-ground activity between the two populations.

• Premise of the study: Numerous long‐term studies in seasonal habitats have tracked interannual variation in first flowering date (FFD) in relation to climate, documenting the effect of warming on the FFD of many species. Despite these efforts, long‐term phenological observations are still lacking

The claim that temperature, rather than food abundance, determines the alternative life history sequences followed by high elevation populations of A. tigrinum is substantiated.

The relationships of adult butterflies were evaluated using the techniques of numerical taxonomy and various sets of characters. Using a total of 196 characters of the external and internal anatomy produced phenograms quite similar to the one arrived at by classical taxonomic techniques. There were,

AbstractParasites can cause a loss of fitness for their hosts, potentially influencing social behaviour patterns of the host that promote or hinder parasite transmission. I studied yellow‐bellied marmots (Marmota flaviventris) and their ectoparasites to determine if ectoparasites reduce the fitness

Herbivorous insects are among the most successful radiations of life. However, we know little about the processes underpinning the evolution of herbivory. We examined the evolution of herbivory in the fly, Scaptomyza flava, whose larvae are leaf miners on species of Brassicaceae, including the widely

Population dynamics and social behavior of 5 populations were studied for 10 yr. Agonistic behavior characterized social interactions among adult females and yearlings who were subordinate. Rates of amicable and of agonistic behavior varied widely within a harem from year to year and among harems in

Stainless steel screen cages were buried in the substrate of Otter Creek, Wisconsin, during spring 1976 and 1977 and the East River, Colorado, during summer 1977 and stocked with known densities of benthos, Cages were retrieved after 3 days of colonization and attrition from a given direction and sp

Pollen movement within and among plants affects levels of inbreeding and plant fitness as well as the spatial scale of genetic differentiation. Pollen movement has primarily been studied as a function of the direct relationships between plants and pollinators; however, nonpollinating floral visitors