The influence of predators on drift and benthic density is important for understanding prey community structure in freshwater streams. Drift activity of stream invertebrates in fishless streams does not differ between day and night, but when visual drift-feeding trout are present, stream invertebrat

In the United States, the 6.2 million kilometers of paved and unpaved public roads and roadsides represent about nineteen percent of the total land area of over nine million Km2 These roadways have major ecological impacts, one of which is dust pollution. When it comes to the effect of dust on plant

Bees feed almost exclusively on nectar and pollen from flowers. However, little is known about how food availability limits bee populations. To gain insights into the potential for food limitation within subalpine bumble bee populations, I examined bee foraging distances and the relationship between

Several prey species have demonstrated a response to predator odors by altering their behavior, but few studies have explored the abilities of prey to discriminate between predator odors or to recognize novel predators. The olfactory abilities of yellow-bellied marmots (Marmota flaviventris) were st

Productive habitats can provide subsidies to neighboring habitats in the form of resources and services; however, little is known about whether subsidies operate in pollination systems. I studied wetland and dry meadow habitats in a subalpine system to assess whether wetlands provide neighboring pol

This project aimed to determine the mechanism of which treehopper nymphs grow in the presence of ants. Nymphs (Publilia modesta) are larger when their mutualist partner (Formica obscuripes) is present. There are two ways in which the nymphs can grow: (1) nymphs grow at the same rate, but are larger

Beavers are an important aspect of the landscape and have been increasing in abundance in montane regions of the western U.S. While beaver impoundments have been shown to affect downstream habitats, their influence is variable and may be attributed in part to variation in the morphology of impoundme

Restoration Ecology is the science of techniques in which environmental degradation can be reversed and the previously existing ecosystems can be reestablished. Revegetation is a common restoration technique and I chose to investigate whether it could be applied to disturbed areas in high-altitude m

Many species of mammals have been shown to modify their behavior in response to olfactory cues of predator presence, but few studies have attempted to directly compare responses to different predators. In this study, we assessed the response of yellow-bellied marmots (Marmota flaviventris) to the ur

Changes in nitrogen availability can alter plant community structure, composition, and abundance as well as higher order interactions. The goal of this study is to investigate the relationships between soil nitrogen, plant reproductive success, and solitary bee behavior and reproduction. Three diffe

Changes in the morphology and physiology of Ipomopsis aggregata and changes in en- vironment were assessed along a roughly 1000 m elevation gradient at seven sites in the Rocky Mountains of central Colorado. Sites at the ends of the gradient had the lowest soil moisture, the lowest two being in sage

This paper describes the timing of floral color change with Lupinus argenteus and the behavior of pollinator visitation to manipulated treatments. In theory plants my benefit from color change in two ways. One way is to direct pollinators to rewarding flowers. This may increase the foraging efficien

There is evidence showing that large differences between age/sex categories in crown morphology of white-crowned sparrows are used to signal status. We investigated the role of more subtle crown characteristics, specifically the proportion of the crown that is white, as a signal used to mediate aggr

Auditory, visual, and olfactory cues of predator presence create a landscape of fear for prey animals. Prey can respond to predation risk perceived from these cues by increasing vigilance, increasing group size, altering habitat use, and reducing activity times. State of the animal and predator type

Anthropogenically induced climate change is expected to effect numerous climatic alterations pertinent to ecosystems, including increased mean global temperature and altered precipitation regimes. High-elevation ecosystems are especially sensitive to climatic changes because slight fluctuations in f

Animals frequently exhibit variation in their behavior. In the past this variation has been treated as statistical error, but research has identified correlated behaviors across contexts, referred to as behavioral syndromes. We focused on yellow-bellied marmots (Marmota flaviventris) and examined vi

The Red-naped sapsucker creates a nest cavity in aspen woodlands each year, required by other bird spp. for nesting, and spends much of its foraging time in willow wetlands. This study attempted to determine a) how does proximity of potential nest trees to forest edge and willows affect the sapsucke

Mayflies in high-elevation streams in Colorado are more vulnerable to risk of predation based on their relative drift propensisties. Baetis bicaudatis, a mayfly that has high drift propensity, has been shown to respond to predation risk by accelerating its metamorphosis into an adult, which results