Life Sciences Commons^™

Effects Of Olfactory And Visual Predators On Nest Success And Nest-Site Selection Of Waterfowl In North Dakota., Jennifer S. Borgo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Selecting a nest site is an important decision for waterfowl. Because most nest failure is due to depredation, the primary selective pressure in choosing a nest site should be to reduce depredation risk. This task is difficult because predators use differing tactics to locate nests, such as olfactory or visual cues. I investigated several components of waterfowl nest-site selection and success on sites with shelterbelts (planted tree-rows) in North Dakota, during the 2006 and 2007 nesting seasons.

I found that meteorological conditions impacted nest depredation; artificial nests were more likely to be depredated when either temperature or dew point was …

Granivores And Restoration: Implications Of Invasion And Considerations Of Context-Dependent Seed Removal, Steven M. Ostoja

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Granivores are important components of sagebrush communities in western North America. These same regions are being altered by the invasion of the exotic annual Bromus tectorum (cheatgrass) that alters physical and biological dynamics in ways that appear to promote its persistence. This research directly relates to the restoration of B. tectorum-dominated systems in two inter-related ways. First, because these landscapes have large quantities of seeds applied during restoration, it is important to determine the major granivore communities in intact sagebrush communities and in nearby cheatgrass-dominated communities. Second, it is important to develop an understanding of patterns of seed harvest …

Ponderosa Pine Mortality And Bark Beetle-Host Dynamics Following Prescribed And Wildland Fires In The Northern Rocky Mountains, Usa, Ryan Stephen Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ponderosa pine delayed mortality, and bark beetle attacks and emergence were monitored on 459 trees for 3 years following one prescribed fire in Idaho and one wildland fire in Montana. Resin flow volume (ml) was measured on 145 fire-injured ponderosa pine 2 and 3 years post-fire. Logistic regression was used to construct two predictive ponderosa pine mortality models, and two predictive bark beetle-attack models. Post-fire delayed tree mortality was greater with the presence of primary bark beetles independent of diameter at breast height (DBH) (cm), and was greater in smaller diameter trees most likely due to direct effects of fire-caused …