Resilient Space: Bighorn Sheep (Ovis canadensis) Ecological Resilience in the Northern Rocky Mountains

• Author / Creator

  Kneteman, Jeffery G.

• Abstract Ecological resilience was defined, reviewed and discussed by synthesis of theory, concepts and empirical evidence presented in the primary literature (Chapter 1). Ecological resilience is concerned with ecological functions and the desirability of alternate states. Management and research are integrated with a focus on persistence of functions, stability of alternate states, responses to disturbance and regeneration, and accommodation of uncertainty and variability. Environmental quality strongly influences the tolerance to disturbance and therefore the resilience of a system or population. The ecological resilience of bighorn sheep to 40 years of environmental variation, including a novel disturbance, was assessed from demographic patterns among census zones and over time (Chapter 2). Asymmetry in census zone productivity and population change determined distribution (immigration, emigration) in response to disturbance as the population process causing change. A reproductive potential of ewes as ~65% of adults, and a recruitment potential of lambs as ~20% of total bighorn sheep were demonstrated as measures of habitat quality that provide a safe operating space. Environmental disturbance also changed the bioavailability of a hormetic (selenium), potentially increasing stress on ecological resilience (Chapter 3). Selenium levels from 85 ungulate populations from western North America were analyzed to identify a safe operating space of 0.06–0.30 ug/g. Selenium levels in populations outside of this interval always displayed low variability indicating individuals occupying low or high selenium environments were respectively always restricted in selenium uptake or unable to avoid high selenium uptake. Management for environmental quality to accommodate deficient or toxic selenium environments is discussed. Management application of immediate technical actions and larger scale actions and a conceptual management framework with scenario examples are presented and discussed (Chapter4).

• Subjects / Keywords

  • Sex ratio
  • Bighorn sheep
  • Habitat quality
  • Ecological resilience
  • Rocky Mountains

• Graduation date

  Fall 2016

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3MG7G37F

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.