Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Life Sciences

Tree Squirrels And Fishers In Northern California: The Effects Of Masting Hardwoods On Stand Use, Andria M. Townsend Jan 2019

Tree Squirrels And Fishers In Northern California: The Effects Of Masting Hardwoods On Stand Use, Andria M. Townsend

Theses and projects

In western North America, tree squirrels such as western gray (Sciurus griseus) and Douglas squirrels (Tamiasciurus douglasii) are potentially important prey for fishers (Pekania pennanti). Western gray squirrels in particular may be highly ranked due to their large body size. Masting trees including black oak (Quercus kelloggii) and tanoak (Notholithocarpus densiflorus) produce an important food source for tree squirrels; therefore, forest stands containing these trees may be useful to foraging fishers. I hypothesized that; 1) the abundance of western gray and Douglas squirrels in a stand is influenced by the mast production capacity of that stand, and 2) fisher stand ...


A Time- And State-Based Approach To Estimate Winter Movement And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Freshwater Creek, California, Nicholas Paul Van Vleet Jan 2019

A Time- And State-Based Approach To Estimate Winter Movement And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Freshwater Creek, California, Nicholas Paul Van Vleet

Theses and projects

Accounting for life history diversity and overwinter survival of juvenile Coho Salmon is important to inform restoration and recovery efforts for this threatened species. Multiple seaward migration patterns of Coho Salmon have been identified, including spring fry migrants, fall and winter parr migrants, and spring smolt migrants. Previous studies have indicated that spring smolt migrants have low overwinter survival rates while they are rearing in upstream habitats, suggesting that freshwater overwinter survival may be one factor that limits smolt production. However, previous research did not account for the early emigration of fall and winter parr migrants from the study area ...


Shade Trees Preserve Avian Insectivore Biodiversity On Coffee Farms In A Warming Climate, Sarah L. Schooler Jan 2019

Shade Trees Preserve Avian Insectivore Biodiversity On Coffee Farms In A Warming Climate, Sarah L. Schooler

Theses and projects

Coffee is an important export in many developing countries, with a global annual trade value of $100 billion. Climate change is projected to drastically reduce the area where coffee is able to be grown. Shade trees may mitigate the effects of climate change through temperature regulation for coffee growth, temperature regulation for pest control, and increase in pest-eating bird diversity. The impact of shade on bird diversity and microclimate on coffee farms has been studied extensively in the Neotropics, but there is a dearth of research in the Paleotropics. I examined the local effects of shade on bird presence and ...


Contribution Of Juvenile Estuarine Residency In A Bar-Built Estuary To Recruitment Of Chinook Salmon (Oncorhynchus Tshawytscha), Emily Katherine Chen Jan 2019

Contribution Of Juvenile Estuarine Residency In A Bar-Built Estuary To Recruitment Of Chinook Salmon (Oncorhynchus Tshawytscha), Emily Katherine Chen

Theses and projects

Estuaries are commonly touted as nurseries for out-migrating salmonids, providing higher prey availability than streams, a physiological transition zone, and refugee from marine predators. Yet the diversity of estuaries makes it difficult to generalize the effect they have on salmonid recruitment. In bar-built estuaries, sandbars form at the mouth of rivers during periods of low flow, closing access to the ocean and disrupting outmigration. In this thesis, I evaluated how residency in a bar-built estuary affects the growth, survival, and ultimately recruitment of Chinook salmon (Oncorhynchus tshawytscha) in Redwood Creek, California. I conducted a mark-recapture experiment on out-migrating juveniles during ...