It is stressed that chemotactile cues are involved only in the final step of oviposition, and that understanding foodplant choice in nature will require in-depth investigation into the mechanics of individual search processes.

The yellow-bellied marmot spends approximately 80% of its life in a burrow. Burrows provide protection from the rigors of the environment, pred- ators and other marmots. They provide a hibernaculum in winter and may func- tion as a nursery in summer. Selection of a burrow site is therefore an import

Many species use refugia to avoid predators, but remaining in a refuge is costly because foraging and engaging in other beneficial activities are curtailed while in a refuge. Thus, we expect that the duration of refuge use will be optimized. We tested a key prediction of this optimization hypothesis

We explored the relative importance of temporal vs. spatial variability to the conditionality of a mutualism between the treehopper Publilia modesta and the ant Formica obscuripes. The effect of the ants on the membracids varied considerably among years. When the effect of the ants on the membracids

Summary1. In the face of human‐induced declines in the abundance of common species, ecologists have become interested in quantifying how changes in density affect rates of biophysical processes, hence ecosystem function. We manipulated the density of a dominant detritivore (the cased caddisfly, Limn

Experimental tools that enable manipulations of organisms at larger scales allow for comparisons of processes across multiple spatial scales and expand our ability to make predictions about ecological processes. We performed reach scale (i.e., 50 m2) manipulations of invertebrate communities in stre

Animals adjust their antipredator behavior according to environmental variation in risk, and to account for their ability to respond to threats. Intrinsic factors that influence an animal's ability to respond to predators (e.g., age, body condition) should explain variation in antipredator behavior.

The behavior of intact Ephemerella infrequens (Ephemeroptera, Ephemerellidae) and Ephemerella with cerci amputated was observed in response to encounters with live predaceous stoneflies (Megarcys signata, Plecoptera: Perlodidae), tethered-live and tethered-model predators, freshly excised stonefly a

We monitored the demographics of the salamander Ambystoma tigrinum nebulosum as part of a community-wide study on the effects of acidification in sub-alpine (elevation 3600 m) ponds in central Colorado. A decline in A. t. nebulosum at this site from 1982 to 1988 has been hypothesized to result from

Spatial variation in pollinator communities or behaviors can underlie floral diversification. Floral traits in the UV spectrum are common and mediate plant–pollinator interactions, but the role of pollinators in driving or maintaining their geographic variation has not been fully explored. We identi

AbstractUnderstanding the effects of climate on the vital rates (e.g., survival, development, reproduction) and dynamics of natural populations is a long‐standing quest in ecology, with ever‐increasing relevance in the face of climate change. However, linking climate drivers to demographic processes

The butterfly Pieris napi (L.) and relatives exemplify recently evolving taxa, exhibiting variation that makes their evolutionary dynamics interesting, but their systematics difficult. Wing-pattern characters commonly used to distinguish these Holarctic insects display both genetic polymorphism and

In harem-polygynous societies, body condition is often correlated with dominance rank. However, the consequences of dominance are less clear. High-ranking males do not inevitably have the highest reproductive success, especially in systems where females mate with multiple males. In such societies, w

Mirror-image stimulation (MIS) was used to determine the individual behavioral phenotypes of 90 adult, 132 yearling, and 135 young yellow-bellied marmots (Marmota flaviventris). Linear typal analysis (LTA) was used to group individuals based on similarities in their MIS scores. Principal component a

Abstract The North American Monsoon occurs July–September in the central Rocky Mountains bringing significant rainfall to Colorado River headwater basins. This rain may buffer streamflow deficiencies caused by reductions in snow accumulation. Using a data‐modeling framework, we explore the importanc

Abstract. Meteorological forcing plays a critical role in accurately simulating the watershed hydrological cycle. With the advancement of high-performance computing and the development of integrated watershed models, simulating the watershed hydrological cycle at high temporal (hourly to daily) and

Brink (1982) characterizes the distribution of standing crop of nectar for Delphinium nelsonii as bonanzablank, based on comparison with a Poisson, but this work disagrees with the use of the Poisson and the resulting conclusions.

During March 1986, several airborne and ground-based silver iodide (AgI) seeding experiments were conducted over the Grand Mesa, Colorado, during a three-day period of northerly flow and shallow orographic cloud. While little natural snowfall was observed during these experiments, supercooled liquid

The observations support the hypothesis that the phagotrophic euglenoids arose from a bondonid ancestor and gave rise to the phototrophs by chloroplast acquisition.

A tomographic inversion of teleseismic shear wave delays has been performed using data collected in the 1992 Program for Array Seismic Studies of the Continental Lithosphere Rocky Mountain Front experiment. The shear wave residuals used as data were corrected for known crustal, sediment and topograp