2,570 results — type: Journal Article
Using the literature to test pollination syndromes - some methodological cautions
“Pollination syndromes” are specific combinations of floral traits that are proposed to evolve convergently across angiosperm lineages in response to different types of animal pollinators. In spite of their long history, pollination syndromes have not been tested adequately–they rarely have been exa
Genetic structure in a montane mayfly <i>Baetis bicaudatus</i> (Ephemeroptera: Baetidae), from the Rocky Mountains, Colorado
Summary1. Populations of a number of sub‐tropical stream insect species have been found to show unexpected patterns of genetic variation, with more differences between samples from the same stream than between whole streams or between subcatchments. Many samples also showed deviations from Hardy–Wei
Multiple paternity in fruits of <i>Ipomopsis aggregata</i> (Polemoniaceae)
Two different mechanisms can result in multiple paternity within fruits: deposition of a mixed pollen load due to carryover of pollen from flower to flower and multiple pollinator visits in close succession. I investigated the extent of multiple paternity within fruits of Ipompsis aggregata containi
The effect of hemosporidian infections on white-crowned sparrow singing behavior
AbstractRelatively little is known about the effects of specific parasites on sexually selected behavioral traits. We subjected free‐living mountain white‐crowned sparrows (Zonotrichia leucophrys oriantha) to a playback experiment to identify the effect of hemosporidian parasites on potentially sexu
The potential to encode sex, age, and individual identity in the alarm calls of three species of Marmotinae
In addition to encoding referential information and information about the sender's motivation, mammalian alarm calls may encode information about other attributes of the sender, providing the potential for recognition among kin, mates, and neighbors. Here, we examined 96 speckled ground squirrels (S
Intraventricular insulin reduces food intake and body weight of marmots during the summer feeding period
It is suggested that during the summer when marmots are not hibernating and are actively feeding, brain insulin levels may play a role in regulating food intake.
Yellow-bellied marmot population dynamics: demographic mechanisms of growth and decline
Multiple environmental factors may act synergistically to influence demographic characteristics, and ultimately the dynamics, of biological populations. Using prospective and retrospective analyses of demographic data from a 40-year study of individually marked animals, we investigated the demograph
Predicting sedimentary bedrock subsurface weathering fronts and weathering rates
AbstractAlthough bedrock weathering strongly influences water quality and global carbon and nitrogen budgets, the weathering depths and rates within subsurface are not well understood nor predictable. Determination of both porewater chemistry and subsurface water flow are needed in order to develop
Plant resources and butterfly habitat selection
The microdistribution of adult subalpine butterflies was examined in relation to several components of the mountain meadow flora in Gunnison County, Colorado. With the exception of two small, sedentary species, there was no significant correlation between the microdistribution of the butterflies and
Dose-dependent effects of nectar alkaloids in a montane plant-pollinator community
SummaryAlthough secondary metabolites are prevalent in floral nectar, the ecological consequences for pollinators and pollination remain relatively unexplored. While often deterrent to pollinators at high concentrations, secondary metabolite concentrations in nectar tend to be much lower than second
Virus diversity and activity is driven by snowmelt and host dynamics in a high-altitude watershed soil ecosystem
Background Viruses impact nearly all organisms on Earth, including microbial communities and their associated biogeochemical processes. In soils, highly diverse viral communities have been identified, with a global distribu‑ tion seemingly driven by multiple biotic and abiotic factors, especially so
The effect of nectar production on neighborhood size
Differences in foraging behavior observed on two plant species with similar floral and inflorescence structures increase the neighborhood size for nectar producing species and make it increasingly unlikely that random drift will be a dominant mode of evolution in populations of these species.
Restoration of vegetation communities of created depressional marshes in Ohio and Colorado (USA): the importance of initial effort for mitigation success
Why hummingbirds hover and honeyeaters perch
Evidence is presented in support of the suggestion that a hovering bird is able to move between flowers more quickly than one that is perching, however, this advantage to hovering may be offset by the higher energetic costs of hovering as compared with perching.
Sandstone-body dimensions in a lower coastal-plain depositional setting: Lower Williams Fork Formation, Coal Canyon, Piceance Basin, Colorado
This study addresses the field-scale architecture and dimensions of fluvial deposits of the lower Williams Fork Formation through analysis of outcrops in Coal Canyon, Piceance Basin, Colorado. The lower Williams Fork Formation primarily consists of mud rock with numerous isolated, lenticular to chan
Genes Suggest Ancestral Colour Polymorphisms Are Shared across Morphologically Cryptic Species in Arctic Bumblebees
Our grasp of biodiversity is fine-tuned through the process of revisionary taxonomy. If species do exist in nature and can be discovered with available techniques, then we expect these revisions to converge on broadly shared interpretations of species. But for the primarily arctic bumblebees of the
Peripheral obstructions influence marmot vigilance: integrating observational and experimental results
Animals generally allocate some time during foraging to detecting predators. We used a combination of observations and an experiment to examine how vegetation height and peripheral obstructions influence vigilance by foraging yellow-bellied marmots ( I Marmota flaviventris /I ). First, we analyzed a
Predator-induced resource heterogeneity in a stream food web
Heterogeneous distributions of resources and organisms are characteristic of most ecosystems, but empirical understanding of the causes and consequences of heterogeneity is limited. We investigated whether predatory fish influenced the heterogeneity (spatial variability) of resources (algae) by modi
Optimal nectar production in a hummingbird pollinated plant
It is hypothesized that the average rate of nectar production per flower for a population of plants is such than an individual plant which possesses this rate has maximum fitness (i.e., is optimal), and predictions concerning nectarProduction in scarlet gilia, a hummingbird pollinated plant are deve
Direct benefits and indirect costs of warm temperatures for high-elevation populations of a solitary bee
AbstractWarm temperatures are required for insect flight. Consequently, warming could benefit many high‐latitude and high‐altitude insects by increasing opportunities for foraging or oviposition. However, warming can also alter species interactions, including interactions with natural enemies, makin
