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Full-Text Articles in Physical Sciences and Mathematics

Phenology And Effects Of Dams On The Success Of Atlantic Salmon Smolt Migrations In The Penobscot River, Maine, Daniel S. Stich Dec 2014

Phenology And Effects Of Dams On The Success Of Atlantic Salmon Smolt Migrations In The Penobscot River, Maine, Daniel S. Stich

Electronic Theses and Dissertations

Atlantic salmon Salmo salar populations are diminished throughout their range and high marine mortality is among the drivers of the failure of many stocks to recover. A goal of salmon recovery is to maximize the number of juvenile ‘smolts’ entering the ocean to offset loss therein. Dam removals and changes to hydropower allocation in Maine’s largest river, the Penobscot River, have occurred as part of the Penobscot River Restoration Project (PRRP). These activities, in addition to stocking have the potential to influence the number of smolts reaching the ocean. Telemetry was used to investigate factors influencing initiation of migratory behavior, …


Late Pleistocene And Holocene Bison Of Grand Canyon And Colorado Plateau: Implications From The Use Of Paleobiology For Natural Resource Management Policy, Jeffrey M. Martin May 2014

Late Pleistocene And Holocene Bison Of Grand Canyon And Colorado Plateau: Implications From The Use Of Paleobiology For Natural Resource Management Policy, Jeffrey M. Martin

Electronic Theses and Dissertations

Bison spp. (bison) fossils are scarce on the Colorado Plateau, especially within the greater Grand Canyon region. Because of the poor fossil record for bison on the plateau and in Grand Canyon National Park, various resource managers have surreptitiously designated bison a nonnative and human-introduced species. The lack of evidence for bison seems to be the result of collection bias rather than a true lack of bison remains. Today, Grand Canyon National Park has a neighboring herd of 350 bison that have meandered unwantedly onto National Park lands from neighboring Forest Service and State of Arizona lands. This study spatiotemporally …


The Development And Application Of A Larval Pallid Sturgeon (Scaphirhynchus Albus) Bioenergetics Model, Laura B. Heironimus Jan 2014

The Development And Application Of A Larval Pallid Sturgeon (Scaphirhynchus Albus) Bioenergetics Model, Laura B. Heironimus

Electronic Theses and Dissertations

Pallid Sturgeon Scaphirhynchus albus are native fish of the Missouri and lower Mississippi River basins and currently listed as an endangered species under the Federal Endangered Species Act. As a result of anthropogenic alterations within the Missouri River, including dredging, channelization, and construction of large reservoirs, Pallid Sturgeon reproduction is reduced or eliminated throughout the species range. Due to a lack of wild progeny, little is known of the larval Pallid Sturgeon and their habitat or environmental requirements. To increase knowledge on the larval Pallid Sturgeon’s physiological requirements for growth and survival, the objective of this study was to develop …


Determining Impacts Of Mountain Lions On Bighorn Sheep And Other Prey Sources In The Black Hills, Joshua B. Smith Jan 2014

Determining Impacts Of Mountain Lions On Bighorn Sheep And Other Prey Sources In The Black Hills, Joshua B. Smith

Electronic Theses and Dissertations

From 2009 to 2013, we assessed cougar (Puma concolor) feeding habits and bighorn sheep (Ovis canadensis) population dynamics in the Black Hills, South Dakota. We used Global Positioning System (GPS) telemetry to locate 1,506 cougar feeding events and found deer (Odocoileus spp.; 83%), primarily white-tailed deer (O. virginianus), dominated cougar diets. Overall ungulate kill rate averaged 0.79 ungulates/week (range = 0.13–1.75 ungulates/week), and was significantly higher (P < 0.001) in summer (xˉ = 0.92; SE = 0.06) than in winter (xˉ = 0.62; SE = 0.06). In contrast, biomass consumed was significantly higher (P = 0.033) in winter (xˉ = 8.23 kg/day; SE = 0.96) than in summer (xˉ = 5.45 kg/day; SE = 0.43), primarily as a result of increased scavenging (winter = 0.21 events/week; summer = 0.08 events/week), which represents the highest documented rate for cougar populations studied. We also documented a relatively high rate of chronic wasting disease- (CWD) infected elk in 2 cougar (1 male; 1 female) diets (64%; 95% CI = 50.3–78.3%) and speculate that CWD infection likely increased elk predation risk. Annual lamb survival was 0.02 (SE = 0.01) with pneumonia (36%) and predation (30%) the leading causes of mortality. We found pneumonia and predation were temporally heterogeneous with lambs most susceptible to predation during the first 2–3 weeks of life, while the greatest risk from pneumonia occurred from weeks 4–8. Annual ewe survival was 0.81 (SE = 0.04) with pneumonia (19%) and predation (19%) the leading causes of documented mortality; 48% were unknown. Additionally, we used vaginal implant transmitters (VITs) to assess capture efficiency and document parturition and neonate lamb bed site selection for bighorn sheep. We found successful VITs increased capture efficiency (95%) over unsuccessfully-vitted ewes (81%) and ewes not equipped with VITs (70%). Bighorn ewes selected for rugged terrain at both macro- and microhabitat scales, while at the macrohabitat scale ewes selected for areas that were close to perennial streams on south and west facing slopes and against anthropogenic disturbance. At the microhabitat scale, neonate lambs tended to select for greater cover and against north facing slopes.