1,559 results — type: Student Paper ·
Species Interactions in Arthropod Communities: Density Dependence and Ant Interactions on Aphid Per Capita Population Growth
Ant and aphid interactions are often assumed to be mutualistic, with both participating parties receiving a benefit that outweighs the cost. Yet this interaction can range between mutualistic and antagonistic due to factors that alter this ratio of cost and benefit. Some factors that can affect the
Dispersal, phenology and habitat preference of subalpine whirligig beetles (Coleoptera: Gyrinidae: Gyrinus)
Whirligig beetle populations from five temporary kettle ponds and one marsh near the Rocky Mountain Biological laboratory, Gunnison County, western Colorado U.S.A. were studied during summer 2010. The purpose of the study was to measure the effects of extreme fluctuating environmental conditions inc
A test of species-area theory on a high disturbance area of the Gothic earthflow
The species-area relationship (SAR) is a widely used concept in ecology, yet there is much controversy over its form. It has traditionally been assumed either to have a simple universal power-law form, S = cAz, or to be idiosyncratic, varying from habitat to habitat, taxa to taxa, and spatial scale
Environmental forces drive morphological variation in an alpine annual plant
The way in which plants respond evolutionarily to environmental change partially depends on the magnitude of variation present within populations. In an attempt to understand the evolutionary response of Androsace septentrionalis (Rock Jasime) to current and future climate change in the Elk mountain
Effect of diatom, <i>Didymosphenia geminata</i>, on Invertebrate Abundance and Composition in Rocky Mountain Streams
The diatom Didymosphenia geminata has become an increasing concern for aquatic habitats. The algae has spread within its native environment and exhibit invasive characteristics, as well as invade ecosystems outside of its native range. D. geminata does not appear to affect the species richness of an
Effects of nectar robbing on pollen deposition and hummingbird-pollinator behavior in <i>Ipomopsis aggregata</i>
Nectar robbing can affect both male and female components of plant reproduction. To understand the mechanisms driving those plant-reproductive outcomes, I studied the effects of nectar robbing on pollen deposition and pollinator behavior in the hummingbird-pollinated host plant Ipomopsis aggregata.
Bumblebee foraging on vertical inflorescences: optimal or not?
Previous studies by Pyke et al. have shown that bumblebees exhibit behavior that is consistent with optimal foraging theory. In this most recent effort, bumblebees were observed foraging on vertical inflorescences and their behavior was compared to a predicted model that would result in a maximum ne
Determining Long-Term Success of Revegetation Efforts in Disturbed Sites
At the Rocky Mountain Biological Laboratory (RMBL), revegetation is an important area of research because there are many areas of disturbed land that are more vulnerable to the spread of invasive species. In my project, I revisited a former student’s revegetation work in order to determine the long-
Comparative approaches to estimating repertoires and American Robin individuality
Song repertoire size is the range of distinct syllables, phrases, and song types created by an individual or population. Variations within songs create complex repertoires, making them difficult to estimate. There are several methods to estimate repertoire size, however prior studies discovered that
A balanced diet: Effects of ant (Hymenoptera: Formicidae) nutritional state on the balance between mutualism and predation upon aphids (Hemiptera: Aphididae)
Mutualisms are commonly dependent on the ecological context in which partners interact. In ant‐aphid interactions, the dietary status of ants has been hypothesized to be one factor that may mediate ant‐aphid interactions. This hypothesis was supported in one laboratory study with one ant species. We
Effects of water addition on above- and below-ground processes in montane meadows
The carbon balance of a system is particularly sensitive to water availability because carbon availability drives both the mechanisms of photosynthesis and decomposition (Huxman et al. 2004 b, Ignace et al. 2007). The carbon balance of terrestrial plants is mainly a function of (i) carbon fixation t
The response of four subalpine forbs to supplemental nitrogen within different soil moisture environments
Anthropogenic environmental change currently threatens to alter resource availability across the planet, likely driving responses by plant species. In the Colorado Rocky Mountains, climate change is expected to decrease soil moisture availability and increased nitrogen deposition is expected to incr
Water-use efficiency may influence the distribution of <i>Ipomopsis aggregata</i>, <i>I. tenuituba</i>, and their natural hybrids along an environmental gradient
In flowering plants, environment-mediated hybrid fitness plays a large role in hybrid zone dynamics. The relationship of physiological traits to hybrid fitness, however, has not been described for many plant systems. In this study, we investigated the effects of soil moisture on water-use efficiency
Butterfly foraging behavior: can butterflies detect nectar in flowering plants?
Optimal foraging theory states that there are benefits and costs from foraging. If the animal shows optimal foraging behavior, the benefits minus the costs from foraging should be maximized. One assumption of optimal foraging theory is that animals can recognize food, which for butterflies means det
What determines the distribution of red-naped sapsuckers in the East River Valley?
The conservation of keystone species and their associates is of great importance due to the disproportionately large role they play in community and ecosystem structure. The Red-naped Sapsucker (Sphyrapicus nuchalis) is considered part of an intricate keystone species complex in the aspen forests of
Climate Change is Causing A Decline in Bombus occidentalis by Reducing its Floral Resources
Concerns of the decline of pollinators and their services have recently been raised. While several hypothesis have been studied, such has the shift of flowering phenology so it no longer overlaps with pollinators and habitat fragmentation, this study investigated the decline of the nectar robbing bu
Linking drift and benthic density along fishless to fish transitions in Rocky Mountain streams
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
Does road dust affect reproduction of <i>Delphinium nelsonii</i> and <i>Ipomopsis aggregata</i>
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
Olfactory predator discrimination abilities of yellow-bellied marmots <i>(Marmota flaviventris)</i>
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
Pollination subsidies between wetland and dry meadow habitats
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