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Full-Text Articles in Physical Sciences and Mathematics
Habitat Use And Abundance Patterns Of Sandhill Cranes In The Central Platte River Valley, Nebraska, 2003–2010, Todd Joseph Buckley
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 …
Natural Selection And Age-Related Variation In Morphology Of A Colonial Bird, Mary Bomberger Brown
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, …