Physical Sciences and Mathematics Commons^™

Habitat Use And Abundance Patterns Of Sandhill Cranes In The Central Platte River Valley, Nebraska, 2003–2010, Todd Joseph Buckley

School of Natural Resources: Dissertations, Theses, and Student Research

The Central Platte River Valley (CPRV) in Nebraska is an important spring stopover area for the midcontinent population of sandhill cranes. Alterations to crop rotation and loss habitat in the CPRV pose a risk to the population. Personnel drove designated routes in the CPRV from 2003–2010 to record the presence of cranes in agricultural fields and estimate abundance. I developed and evaluated models to predict habitat use and flock sizes. Alfalfa was predicted to receive the highest use followed by corn, soybeans, winter wheat, grassland, and shrubland. Use of all habitats and flock size increased as field area increased. Flock …

Breeding Fidelity And Landscape Effects On Distribution Of Mallards And Duck Broods In The Nebraska Sandhills, Zachary J. Cunningham

School of Natural Resources: Dissertations, Theses, and Student Research

I investigated aspects of mallard (Anas platyrhnchos) breeding ecology in the Nebraska Sandhills during 2007-2008. Previous work in this region suggests that nest success is low for a large area of intact grassland such as the Sandhills. My goal was to conduct a local-scale examination of age distribution and return rates of mallards, and a large-scale examination of brood distribution in the Sandhills region as a whole. This information will help explain factors contributing to the low nest success previously observed, determine relationships between landscape composition and spatial distribution of waterfowl in the Sandhills, and predict productivity and …

Spatial Accuracy Of Climate Networks In Nebraska, Andrea J. Coop

School of Natural Resources: Dissertations, Theses, and Student Research

Climate data has become increasingly scrutinized for its accuracy because of the need for reliable predictions about climate change. The U.S. has taken great strides to keep up with the demand for accurate climate data. Over the last thirty years, vast improvements to instrumentation, data collection, and station siting have created more accurate data records. This study is to explore the accuracy of existing networks. This study analyzes three climate networks used in Nebraska: the U.S. Historical Climatology Network (HCN), the Automated Weather Data Network (AWDN), and the newest network, the U.S. Climate Reference Network (CRN). Each of these networks …

Late Holocene History Of Dune Activity Along The Elkhorn River In Northeastern Nebraska, Rebecca A. Young

School of Natural Resources: Dissertations, Theses, and Student Research

The Nebraska Sand Hills have been an important study area for dune activation and the nature of prehistoric drought events in the Great Plains. However, little has been done to understand the impact of these droughts to smaller dune fields along the eastern margin of the Great Plains. This study focuses on the Stanton dune field which is found about 145 km east of the Sand Hills along the southern edge of the Elkhorn River valley in northeastern Nebraska. With a wetter and slightly cooler climate regime than that of the Nebraska Sand Hills and most other central Great Plains …

Natural Selection And Age-Related Variation In Morphology Of A Colonial Bird, Mary Bomberger Brown

School of Natural Resources: Dissertations, Theses, and Student Research

In May 1996, inclement weather led to the deaths of thousands of Cliff Swallows (Petrochelidon pyrrhonota) in Nebraska. Survivors had larger skeletons, shorter wings and tails, and less wing asymmetry than non-survivors. This population was followed for 10 years to study 1) whether natural selection events result in permanent microevolutionary changes, 2) if variation in climate affects the development of morphological traits, and 3) if morphological traits vary systematically with age.

Patterns in morphology exhibited by swallows following the selection event were studied by measuring yearling birds. Wing and middle tail lengths decreased, beak length and width increased, …