COMPARISON OF MODIFIED FLOTAC AND BAERMANN TECHNIQUES FOR QUANTIFYING LUNGWORM LARVAE IN FREE-RANGING BIGHORN SHEEP (OVIS CANADENSIS) FECES, MONTANA, USA

2015 ◽  
Vol 51 (4) ◽  
pp. 843-848
Author(s):  
Paul W. Snyder ◽  
John T. Hogg ◽  
Vanessa O. Ezenwa
Keyword(s):  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Free Ranging

Factors influencing heart rate in free-ranging bighorn sheep: a physiological approach to the study of wildlife harassment

1979 ◽  
Vol 57 (10) ◽  
pp. 2010-2021 ◽  
Author(s):  
Robert A. MacArthur ◽  
Ronald H. Johnston ◽  
Valerius Geist
Keyword(s):  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Activity Level ◽  
Base Line ◽  
Vehicular Traffic ◽  
Behavioral Reactions ◽  
Factors Influencing ◽  
Close Range ◽  
Physiological Approach ◽  
Free Ranging

The telemetered heart rates (HR) of unrestrained female bighorn sheep (Ovis canadensis canadensis) were recorded under various behavioral and environmental circumstances. In all ewes HR varied positively with activity level and inversely with distance to a road traversing the study area. The HR recorded from animals moving at night or through timber by day were higher than during daytime movement across open slopes.Responses to transient stimuli varied greatly. The appearance of free-ranging canids evoked maximal increases in HR in all ewes. Vehicular traffic and aircraft elicited HR responses only at close range (< 200 m). Most (78.1%) HR responses to disturbing stimuli preceded or occurred in the absence of overt behavioral reactions. The HR usually peaked within 60 s of the onset of the response and recovered to predisturbance base line in less than 200 s. The appearance and continued presence (1–10 min) of a human within 50 m of the sheep resulted in a 20% rise in mean HR. The significance of these findings is discussed in relation to the behavior, ecology, and bioenergetics of bighorn sheep.

Seasonal variation of red blood cell survival in desert bighorn sheep (Ovis canadensis cremnobates)

1984 ◽  
Vol 62 (7) ◽  
pp. 1227-1231 ◽  
Author(s):  
Jack C. Turner
Keyword(s):  
Body Weight ◽  
Seasonal Variation ◽  
Life Span ◽  
Blood Cells ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Desert Bighorn Sheep ◽  
The Mean ◽  
Ad Libitum ◽  
Free Ranging

The life-span of red blood cells (RBCs) in captive and free-ranging desert bighorn sheep was measured with [32P]diisopropylfluorophosphate. The mean winter RBC life-span (156.6 days) was not significantly affected by season for captive animals maintained on a high nutritional plane and water, ad libitum. Free-ranging bighorn demonstrated a significant (P < 0.001) difference between mean winter (155.9 days) and summer (203.9 days) RBC survival. Dehydration of captive bighorn significantly increased RBC survival, closely approximating that found in summer free-ranging animals. Desert bighorn RBCs exhibited an aseasonal facultative response to the availability of water. RBC life-span was significantly (P < 0.05) increased from 153.5 to 197.7 days in animals experiencing extreme dehydration. The large spleen, relative to body weight, may accommodate extensive fluctuations in total RBC volume measured during dehydration and rehydration, preventing premature RBC degradation and an increased water requirement.

Sheep-Associated Malignant Catarrhal Fever–Like Skin Disease in a Free-Ranging Bighorn Sheep (Ovis canadensis), Alberta, Canada

2017 ◽  
Vol 53 (1) ◽  
pp. 153-158 ◽  
Author(s):  
Owen M. Slater ◽  
Jeanine Peters-Kennedy ◽  
Manigandan Lejeune ◽  
David Gummer ◽  
Bryan Macbeth ◽  
...  
Keyword(s):  
Skin Disease ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Malignant Catarrhal Fever ◽  
Free Ranging

scholarly journals A Review of Hypothesized Determinants Associated with Bighorn Sheep (Ovis canadensis) Die-Offs

2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
David S. Miller ◽  
Eric Hoberg ◽  
Glen Weiser ◽  
Keith Aune ◽  
Mark Atkinson ◽  
...  
Keyword(s):  
Management Practices ◽  
Single Agent ◽  
Disease Outbreaks ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Mitigation Strategies ◽  
Wildlife Diseases ◽  
Land Use And Management ◽  
Study Designs ◽  
Free Ranging

Multiple determinants have been hypothesized to cause or favor disease outbreaks among free-ranging bighorn sheep (Ovis canadensis) populations. This paper considered direct and indirect causes of mortality, as well as potential interactions among proposed environmental, host, and agent determinants of disease. A clear, invariant relationship between a single agent and field outbreaks has not yet been documented, in part due to methodological limitations and practical challenges associated with developing rigorous study designs. Therefore, although there is a need to develop predictive models for outbreaks and validated mitigation strategies, uncertainty remains as to whether outbreaks are due to endemic or recently introduced agents. Consequently, absence of established and universal explanations for outbreaks contributes to conflict among wildlife and livestock stakeholders over land use and management practices. This example illustrates the challenge of developing comprehensive models for understanding and managing wildlife diseases in complex biological and sociological environments.

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