Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
Articles 1 - 3 of 3
Full-Text Articles in Animal Sciences
Wintering Bald Eagle Count Trends In The Conterminous United States, 1986-2010, Wade L. Eakle, Laura Bond, Mark R. Fuller, Richard A. Fischer, Karen Steenhof
Wintering Bald Eagle Count Trends In The Conterminous United States, 1986-2010, Wade L. Eakle, Laura Bond, Mark R. Fuller, Richard A. Fischer, Karen Steenhof
Biomolecular Research Center Publications and Presentations
We analyzed counts from the annual Midwinter Bald Eagle Survey to examine state, regional, and national trends in counts of wintering Bald Eagles (Haliaeetus leucocephalus) within the conterminous 48 United States from 1986 to 2010. Using hierarchical mixed model methods, we report trends in counts from 11 729 surveys along 844 routes in 44 states. Nationwide Bald Eagle counts increased 0.6% per yr over the 25-yr period, compared to an estimate of 1.9% per yr from 1986 to 2000. Trend estimates for Bald Eagles were significant (P ≤ 0.05) and positive in the northeastern and northwestern U.S. …
Is Habitat Use By Greater Sage-Grouse Proportional To Availability Of Plant Morphotypes?, Jacqueline Peña, Marcella Fremgen, John C. Connelly, Jennifer Forbey
Is Habitat Use By Greater Sage-Grouse Proportional To Availability Of Plant Morphotypes?, Jacqueline Peña, Marcella Fremgen, John C. Connelly, Jennifer Forbey
College of Arts and Sciences Presentations
Greater Sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) select sagebrush plants for food that are high in protein. However, sagebrush produce toxins called monoterpenes that can inhibit enzymatic reactions and interrupt cellular processes and therefore result in decreased intake by sage-grouse. Moreover, species, subspecies, populations, and morphotypes of sagebrush can vary in the concentration of toxins produced. Preliminary analysis has shown that different morphotypes of sagebrush have different chemical profiles, and this may influence selection at a scale below species. Our research aims to determine whether sage-grouse select specific morphotypes of sagebrush to maximize biomass consumed per bite or minimize …
Plant Driven Movement: Does Plant Quality Affect The Foraging Patterns Of Successful Male Sage-Grouse (Centrocercus Urophasianus)?, Karli Graski, Marcella R. Fremgen, Gail Patricelli, Alan Krakauer, Jennifer S. Forbey
Plant Driven Movement: Does Plant Quality Affect The Foraging Patterns Of Successful Male Sage-Grouse (Centrocercus Urophasianus)?, Karli Graski, Marcella R. Fremgen, Gail Patricelli, Alan Krakauer, Jennifer S. Forbey
College of Arts and Sciences Presentations
The structural and dietary quality of plants is highly variable across the landscape and may influence energy acquisition by herbivores needed for energy dependent activities. For sage-grouse, male display efforts are energetically expensive, with successful males expending up to four times their basal metabolic rate to display. Previous work found that males who had the greatest energy expenditure during the lekking season also lost the least weight and foraged farthest from the lek. We hypothesized that the energetic benefit of foraging farther from the lek is due to higher quality food or cover compared to near lek vegetation. To initially …