619 results — topic: Flowering & Pollination
Assessing the quality of different ant species as partners of a myrmecophilous butterfly
Assessment of the quality of different ant species as partners of the facultatively myrmecophilous lycaenid butterfly Glaucopsyche lygdamus found that F. obscuripes may act as a parasite of the general association between G. lyg damus and ants under certain conditions.
Inferring climate from angiosperm leaf venation networks
Summary Leaf venation networks provide an integrative linkage between plant form, function and climate niche, because leaf water transport underlies variation in plant performance. Here, we develop theory based on leaf physiology that uses community‐mean vein density to predict growing season temper
The hummingbird's restraint: a natural model for weight control
In July, cessation of territorial activity was accompanied by a regular upward drift of dawn weight, suggesting that weight had been regulated previously as a balance between expenditure and intake, perhaps without involving set-points.
Pollination, breeding system, and genetic structure in two sympatric <i>Delphinium</i> (Ranunculaceae) species
Two sympatric Delphinium species, D. barbeyi and D. nuttallianum, are ecologically and morphologically similar. However, D. barbeyi has multiple, large inflorescences while D. nuttallianum has a single, small inflorescence. These differences in floral display should result in greater intraplant poll
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 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.
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
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
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
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
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
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 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.
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
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
Palynology of Pinedale Sediments, Devlins Park, Boulder County, Colorado
A core of varved lake sediments from Devlins Park, Front Range, Colorado, has yielded a radiocarbon-dated pollen record of environments during the last major advance of Pinedale ice. The downstream end of Devlins Park was dammed by Pinedale ice from 22,400 to 12,180 BP, creating the lake. The pollen
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
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
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
