This study is the first to document the use of hydrodynamic cues by stream-dwelling predators for discrimination of prey from nonprey and provides a mechanism to explain selective predation by stoneflies on Baetis in nature.

The Ipomopsis aggregata species complex (Polemoniaceae) includes species pairs that hybridize readily in nature as well as pairs that meet along contact zones with no apparent hybridization. Artificial hybrids can be made between I. aggregata and I. arizonica, yet morphological intermediates between

AbstractHabitat selection may have population level consequences and ultimately may influence a population's local persistence or extinction. We capitalized on a long‐term study (1962–2004) of yellow‐bellied marmotsMarmota flaviventrisin and around the Rocky Mountain Biological Laboratory, Gothic, C

AbstractUnderstanding the influence of environmental variability on population dynamics is a fundamental goal of ecology. Theory suggests that, for populations in variable environments, temporal correlations between demographic vital rates (e.g., growth, survival, reproduction) can increase (if posi

Aquilegia elegantula Greene and A. caerulea James occur in montane and subalpine habitats in the southern Rocky Mountains of western North America. The red and yellow flowers of A. elegantula are nodding, odorless, protogynous, and secrete a concentrated (44%) sucrose nectar in the floral spurs. See

Abstract Temporal correlations among demographic parameters can strongly influence population dynamics. Our empirical knowledge, however, is very limited regarding the direction and the magnitude of these correlations and how they vary among demographic parameters and species’ life histories. Here,

Hypothetically, flowers which have coevolved with pollination by hummingbirds could provide both energy and water balance simultaneously if they produced nectars of appropriate concentrations which depend upon environmental temperature.

We simulated pollination in a plant population and explored how pollen dispersal distance and allocation among recipient individuals evolved in response to direct selection on three loci coding for dispersal phenotype and in response to indirect selection on two unlinked "genetic congruence" loci. F

A survey of approximately 60 ponds in the Gunnison Basin, Gunnison and Pitkin counties, Colorado, U.S.A., showed a cor- relation between the thermal ranges of the ponds and the life history pattern of Ambystoma tigrinum populations. Characterization of physical and biotic parameters allowed a rankin

Mutualistic networks are key for the creation and maintenance of biodiversity, yet are threatened by global environmental change. Most simulation models assume that network structure remains static after species losses, despite theoretical and empirical reasons to expect dynamic responses. We assess

Macrophage polarization refers to how macrophages have been activated at a given point in space and time. Polarization is not fixed, as macrophages are sufficiently plastic to integrate multiple signals, such as those from microbes, damaged tissues, and ...Read More

Abstract. 1. Foraging effort can vary among age classes and between the sexes. In many Lepidoptera, young males feed from mud, dung or carrion in a behaviour known as ‘puddling’, whereas females rarely puddle. In at least one species, males transfer sodium gained from puddling to females at mating f

Abstract In the early 1900s, tree-ring scientists began analyzing the relative widths of annual growth rings preserved in the cross sections of trees to infer past climate variations. Now, many ring-width index (RWI) chronologies, each representing a specific site and species, are archived online wi

Investigation of this mating system in Epeerus longimanus, a mayfly of the western United States that forms swarms that are quite large, finds that swarm locations are not explainable as feeding or emergence sites, but they do correlate with landscape features.

1. The extent to which flower colour and other visual cues influence butterfly flower choice in the field is poorly understood, especially in comparison with choices by Hymenoptera. 2. Using a novel approach to studies of visitation behaviour by butterflies, flower colour of four Asteraceae species

Dinosaur footprint casts from a Mesaverde (Campanian) coal mine near Gunnison, Colorado resemble those of the notorious "mystery dinosaur, Xosaurus" which was probably a giant hadrosaur. Existing footprint descriptions, although obscure and hard to verify, are too important to overlook, particularit

It is concluded that either temporal differences or size differences of copepodids and adults would allow coexistence and that extreme size differences are probably unimportant compared to morphological differences of feeding appendages and perhaps behavioral differences.

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

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.

Hummingbirds depend on floral nectars for energy. This entails a significant water excess which is eliminated in chronic diuresis. In the eight species from which we obtained urine samples, solutes were conserved by reducing urine osmotic concentrations to approximately one-fifth of plasma levels. S