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Full-Text Articles in Physical Sciences and Mathematics
A Post-Pneumonia Epizootic Evaluation Of The Rapid City, South Dakota Bighorn Sheep Herd, Amanda N. Ensrud
A Post-Pneumonia Epizootic Evaluation Of The Rapid City, South Dakota Bighorn Sheep Herd, Amanda N. Ensrud
Electronic Theses and Dissertations
Pneumonia is a major factor affecting populations of free-ranging bighorn sheep (Ovis canadensis) across western North America. Pneumonia can occur in large-scale epizootics, during which greater than half of the population typically dies. After these epizootics, surviving ewes continue to conceive and bear lambs. However, lamb recruitment may remain low due to periodic or annual pneumonia outbreaks causing high lamb mortality rates, sometimes greater than 90%. Our study focused on the Rapid City, South Dakota bighorn sheep (BHS) herd that has recorded pneumonia-induced population decline since 2009. The first objective was to improve lamb health and survival by identifying and …
Epidemiological Investigations Of Bighorn Sheep Respiratory Disease And Implications For Management, Brandi L. Felts
Epidemiological Investigations Of Bighorn Sheep Respiratory Disease And Implications For Management, Brandi L. Felts
Electronic Theses and Dissertations
Infectious respiratory disease has long been identified as the cause of bighorn sheep (Ovis canadensis) historical declines and extirpations, and Mycoplasma ovipneumoniae (Movi) is the primary pathogen inducing disease and mortality. Population-level effects of pneumonia events range from mild to extirpation. Variable individual response to pathogen exposure emerges from dynamic interactions between competing evolutionary processes within the host and pathogen. Understanding impacts of this evolutionary warfare is essential to assessing long-term impacts of pathogen invasion and developing appropriate countermeasures to protect population health. Freeranging populations are faced with spillover infections from domestic sheep and goats as well as …
Evaluation Of The Deadwood Bighorn Sheep Herd Translocation, Ty J. Werdel
Evaluation Of The Deadwood Bighorn Sheep Herd Translocation, Ty J. Werdel
Electronic Theses and Dissertations
From 2015-2017, we evaluated a newly established bighorn sheep (Ovis canadensis) herd in the Deadwood Region of the Black Hills, South Dakota. Our objectives were to 1a) determine annual survival rates, 1b) determine cause-specific mortality, 1c) estimate population size, 2a) assess genetic diversity, 2b) assess disease prevalence, 3) evaluate movement patterns post-release, 4a) evaluate 3rd-order habitat selection, and 4b) estimate herbaceous biomass at foraging sites post-release of translocated bighorn sheep. In February 2015, we captured and translocated 26 bighorn sheep from the Luscar Mine near Hinton, Alberta, Canada to the Deadwood Region of the Black Hills, South Dakota. Overall annual …
Determining Impacts Of Mountain Lions On Bighorn Sheep And Other Prey Sources In The Black Hills, Joshua B. Smith
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.