Surrogacy and Umbrella Relationships of Grizzly Bears and Songbirds is Scale Dependent

• Author / Creator

  Cicon, Emily

• The consideration of different spatial scales in ecological studies, including assessments of surrogacy, is often suggested, but less commonly implemented. Species utilize their environments at many spatial scales; therefore, the relationships between species including surrogate relationships, will vary depending on the scale of analysis. Here I study the potential for grizzly bears to act as a surrogate for songbird conservation in Alberta across three spatial scales: (1) the broad-scale umbrella effect that uses the scale of individual home ranges of bears, (2) an intermediate scale that uses seasonal patch-level resource selection function models (maps) to index local use (avoidance to selection) of habitats by grizzlies within a region, and (3) the localized scale that uses individual bear telemetry locations with known activity. The relationship between grizzly bears and songbird diversity changed over the three spatial scales examined – with the strongest results observed at the largest scale and little to no relationship at the intermediate and localized scales, respectively. This emphasizes the importance of spatial scale in surrogacy studies. As well as focusing on the surrogacy potential of grizzly bears more intensively, I also tested the idea that flagship species are equivocal to umbrella species by comparing the surrogate relationships of grizzly bears against two other well-known flagship species in Canada – the greater sage-grouse and woodland caribou – as surrogates for the same group of interest, songbirds. Grizzly bears were found to outperform the other candidate species at my largest spatial scale in Alberta (umbrella) – illustrating that a flagship can also be an umbrella species, but not in all cases. I also demonstrate that not all areas of grizzly bear range are equally effective in providing surrogate potential which emphasizes the consideration of geographic variation which can significantly affect the potential for a signal in surrogacy.
  A primary motivation for using surrogate species is to simplify conservation action – using the management of one species’ to guide the conservation of many. While this appears to be a theoretically simple idea, it has proved to be contentious in the literature and its efficacy circumstantially difficult to predict. This study contributes to knowledge on the applications of surrogacy – helping to emphasize the importance of spatial scale in evaluating a species’ surrogacy potential.

• Subjects / Keywords

  • Umbrella Species
  • Spatial Scale
  • Species Surrogacy
  • Grizzly Bear
  • Flagship Species
  • Songbird

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-g4zh-8k60

• License

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