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Life Sciences Commons

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

2020

Ecology and Evolutionary Biology

Electronic Theses and Dissertations

Survival

Articles 1 - 3 of 3

Full-Text Articles in Life Sciences

American Eel Behavior And Survival In An Impounded River System, Matthew A. Mensinger Dec 2020

American Eel Behavior And Survival In An Impounded River System, Matthew A. Mensinger

Electronic Theses and Dissertations

After beginning life in the Sargasso Sea, American eel enter river systems as juveniles and swim upstream in pursuit of freshwater habitat. Many encounter dams during this migration which act as barriers to upstream movement and limit eel establishment in headwater systems. Some dams have been retrofitted with fishways to improve watershed connectivity, but the individual selection imposed by these structures remains uncharacterized. We considered whether individual differences in behavior (i.e., personality) may be used to predict the propensity of juveniles to use a passage structure, suggesting that eel personality may predict access to habitat upstream of dams. Migrating, juvenile …


Movement And Survival Of Atlantic Salmon Smolts In The Penobscot River, Maine, Alejandro Molina Moctezuma Aug 2020

Movement And Survival Of Atlantic Salmon Smolts In The Penobscot River, Maine, Alejandro Molina Moctezuma

Electronic Theses and Dissertations

The Penobscot River system hosts the largest population of endangered Atlantic salmon Salmo salar in the United States. However, total adult returns in this river remain low. Historically low numbers led to listing of the distinct population segment (DPS) in 2000, and the Penobscot River population was included in the DPS in 2009. Reducing mortality in all life stages is crucial for the recovery of Atlantic salmon populations. One of the life stages associated to high mortality is the juvenile stage (smolts), in which individuals migrate downstream towards the estuary. During this migration smolts face a series of new conditions …


Understanding How Agricultural Intensification Impacts Ring-Necked Pheasant Distribution And Survival In Eastern South Dakota, Hilary R. Kauth Jan 2020

Understanding How Agricultural Intensification Impacts Ring-Necked Pheasant Distribution And Survival In Eastern South Dakota, Hilary R. Kauth

Electronic Theses and Dissertations

Historically, pheasants (Phasianus colchicus) have thrived in South Dakota in conjunction with successful land retirement programs or early farming practices through the 1950s, which created interspersions of agriculture and native landscapes that were ideal for pheasants. Recently, the Prairie Pothole ecosystem has undergone rapid agroeconomic expansion, effectively reducing ideal interspersions of native prairie and cropland into agriculturally homogeneous landscapes. Indices of pheasant abundance have suggested persistent population declines since 2008, raising concerns regarding landscape suitability. Our goal was to understand how agriculture intensification impacts pheasant ecology. The objectives were to: 1) estimate overwinter hen probability of survival, resource …