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Full-Text Articles in Life Sciences

Breeding Time In A Migratory Songbird Is Predicted By Drought Severity And Group Size, Charles R. Brown, Mary Bomberger Brown Oct 2014

Breeding Time In A Migratory Songbird Is Predicted By Drought Severity And Group Size, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Global climate change is altering the breeding phenology of many organisms, and one reported consequence of warmer average temperatures is earlier breeding times in migratory songbirds of north temperate latitudes. Less studied are the potential interactions between earlier breeding and social behavior in colonial species. We investigated how breeding time, as measured by colony initiation dates across the entire summer, in Cliff Swallows (Petrochelidon pyrrhonota) of southwestern Nebraska, USA, changed over a 30-year period and could be predicted by climatic variables, year, and colony size. Mean colony initiation date became earlier over the study, with variation best predicted …


Warming, Competition, And Bromus Tectorum Population Growth Across An Elevation Gradient, Aldo Compagnoni, Peter B. Adler Sep 2014

Warming, Competition, And Bromus Tectorum Population Growth Across An Elevation Gradient, Aldo Compagnoni, Peter B. Adler

Green Canyon Environmental Research Area, Logan Utah

Cheatgrass (Bromus tectorum) is one of the most problematic invasive plant species in North America and climate change threatens to exacerbate its impacts. We conducted a two‐year field experiment to test the effect of warming, competition, and seed source on cheatgrass performance across an elevation gradient in northern Utah. We hypothesized that warming would increase cheatgrass performance, but that warming effects would be limited by competing vegetation and by local adaptation of cheatgrass seed sources. The warming treatment relied on open top chambers, we removed vegetation to assess the effect of competition from neighboring vegetation, and we reciprocally …


Effect Of Increased Water Temperature On Warm Water Fish Feeding Behavior And Habitat Use, Eric Walberg Aug 2014

Effect Of Increased Water Temperature On Warm Water Fish Feeding Behavior And Habitat Use, Eric Walberg

Journal of Undergraduate Research at Minnesota State University, Mankato

Global warming could cause changes in species behavior and life history. Stream fish may be significantly affected by climate change because individuals are restricted in their movements by water systems and other physical factors, preventing migration to locations more thermally suitable. The effect of warmer waters on stream fish could change behavior and affect the fish species survival and ultimately ecosystem function. During my experiment I observed the effects of increased water temperature on the feeding behavior and habitat use of two native Minnesota fish species, black crappie (Pomoxis nigromaculatus) and black bullhead (Ameiurus melas). An increase of 2oC over …


Changes In Spring Arrival And Fall Departure Dates Of Migratory Birds As An Indication Of Local Climate Change: A Phenological Study Of New York State's Capital Region Using Citizen Science, Olivia C. Townsend Jun 2014

Changes In Spring Arrival And Fall Departure Dates Of Migratory Birds As An Indication Of Local Climate Change: A Phenological Study Of New York State's Capital Region Using Citizen Science, Olivia C. Townsend

Honors Theses

Climate change is becoming an increasingly important topic of scientific research, and studies commonly analyze biological indicators. Migratory birds are responsive to environmental changes because life cycles depend on finding proper seasonal locations. eBird is a citizen science database launched by the Cornell Lab of Ornithology and National Audubon Society in 2002, and this study focused on eBird data to analyze migratory shifts over the past two decades for the Green-winged Teal (Anas crecca), Northern Pintail (Anas acuta), Bufflehead (Bucephala albeola), Common Goldeneye (Bucephala clangula), Common Merganser (Mergus merganser), Red-breasted Merganser (Mergus serrator), Canada Goose (Branta canadensis), Snow Goose (Chen …


Effects Of Climate Change On The Potential Distribution Of 12 Endemic Lizards Of The Genus Plestiodon Of Mexico, Mayra Oyervides May 2014

Effects Of Climate Change On The Potential Distribution Of 12 Endemic Lizards Of The Genus Plestiodon Of Mexico, Mayra Oyervides

Theses and Dissertations - UTB/UTPA

Anthropogenic global climate change is a large scale threat to biodiversity. Species distribution models (SDMs) were created to assess the possible effects of climate change on the distribution of 12 Plestiodon lizards of Mexico. Species presence data was obtained from online databases, literature, and field data. Occurrences were correlated with 19 climatic variables from www.worldclim.org to model species' current suitable habitat. These models were then projected to future (2050) conditions for which bioclimatic information was downloaded from the CCAFS website. Forecasts were made using 4 General Circulatory Models, 2 IPCC scenarios, and the software MaxEnt. Models were replicated 10 times …


Post-Den Emergence Behavior And Den Detection Of Polar Bears (Ursus Maritimus) In Northern Alaska And The Southern Beaufort Sea, Rusty Wade Robinson Mar 2014

Post-Den Emergence Behavior And Den Detection Of Polar Bears (Ursus Maritimus) In Northern Alaska And The Southern Beaufort Sea, Rusty Wade Robinson

Theses and Dissertations

Pregnant polar bears (Ursus maritimus) construct maternal dens out of snow in the autumn where they give birth to and raise altricial young. In recent years, there has been a decrease in polar sea ice extent and thickness, which has led to changes in denning behavior. One such change in the southern Beaufort Sea (SBS) is that polar bears are selecting maternal den sites on land, rather than on unstable sea ice. This change, coupled with expanding petroleum exploration along Alaska's North Slope, heightens the likelihood of bear-human interactions at maternal den sites. The purpose of this research …


Warming, Soil Moisture, And Loss Of Snow Increase Bromus Tectorum’S Population Growth Rate, Aldo Compagnoni, Peter B. Adler Jan 2014

Warming, Soil Moisture, And Loss Of Snow Increase Bromus Tectorum’S Population Growth Rate, Aldo Compagnoni, Peter B. Adler

Green Canyon Environmental Research Area, Logan Utah

Climate change threatens to exacerbate the impacts of invasive species. In temperate ecosystems, direct effects of warming may be compounded by dramatic reductions in winter snow cover. Cheatgrass (Bromus tectorum) is arguably the most destructive biological invader in basins of the North American Intermountain West, and warming could increase its performance through direct effects on demographic rates or through indirect effects mediated by loss of snow. We conducted a two-year experimental manipulation of temperature and snow pack to test whether 1) warming increases cheatgrass population growth rate and 2) reduced snow cover contributes to cheatgrass’ positive response to …


Species Distribution Modelling Using Bioclimatic Variables To Determine The Impacts Of A Changing Climate On The Western Ringtail Possum (Pseudocheirus Occidentals; Pseudocheiridae), Shaun Molloy, Robert Davis, Eddie Van Etten Dec 2013

Species Distribution Modelling Using Bioclimatic Variables To Determine The Impacts Of A Changing Climate On The Western Ringtail Possum (Pseudocheirus Occidentals; Pseudocheiridae), Shaun Molloy, Robert Davis, Eddie Van Etten

Shaun W Molloy Dr

The ngwayir (western ringtail possum Pseudocheirus occidentalis) is an arboreal species endemic to south-western Australia. The range and population of this species have been significantly reduced through multiple anthropogenic impacts. Classified as vulnerable, the ngwayir is highly susceptible to extremes of temperature and reduced water intake. Ngwayir distribution was determined using three different species distribution models using ngwayir presence records related to a set of 19 bioclimatic variables derived fromhistorical climate data, overlaid with 2050 climate change scenarios.MaxEnt was used to identify core habitat and demonstrate how this habitat may be impacted. A supplementary modelling exercise was also conducted to …