The term surrogate species generally refers to a species which is a proxy for one or many other species3. It is therefore viewed as a management “shortcut”- reducing single species management in favor of a simplified multi-species management approach8. Grizzly bear (Ursus arctos) is a Threatened species within the province of Alberta1 and is managed through a provincial recovery plan2. Much like grizzly bears, songbirds are a taxa of conservation concern. Populations of birds in Canada have declined by over 10% in the past 40-50 years7. In addition to these statuses, all migratory songbirds are protected under the Migratory Birds Convention Act6. Given the statuses and conservation requirements for both grizzly bears and songbirds, the potential for surrogacy becomes a question of interest; however, because surrogacy can be assessed on different scales and yield differing results5 and the significance of including different scales to analyze surrogacy has been stressed4, a multi-scale analysis is necessary.
A) The smaller scale analysis compares grizzly bear use sites to non-use areas.
1) Determine whether sites frequented by grizzly bears are associated with higher overall songbird diversity and/or if it varies with songbird guild; and
2) Determine whether there are differences in the songbird assemblage based on type or features of grizzly bear use locations (activity of bear, dominant vegetation type, etc.)
Methods: Grizzly bear use locations are determined from telemetry data gathered from the Foothills Research Institute in the Yellowhead Bear Management Region. Sixty-six of these 15 m radius sites were selected, with an additional sixty-six random sites surveyed for comparison. Autonomous recording units (ARUs) were placed at these sites during both the spring migration and summer breeding period in 2017. ARU recordings were analyzed for species presence and number of individuals. Grizzly bear sites are categorized based on vegetation within a 15 m radius of the ARU using field data collected, as well as vegetation within 150 and 500 m using landcover data provided by ABMI.
B) The larger scale analysis compares grizzly bear surrogacy (on this large scale known as umbrella effects / species) to other iconic conservation species in Alberta.
1) Determine if grizzly bear, caribou, and/or greater sage grouse have the potential to serve as umbrella species for songbirds based on songbird presence, songbird species at risk presence, and overall bird presence, diversity, and uniqueness within the broader context of home ranges and large conservation priority areas.
2) Compare the above-mentioned bird metrics with area size to determine which of the three species (if any) would best serve as an umbrella species for bird conservation.
3) Compare bird metrics between BMAs within the Alberta grizzly bear range
Methods: Using existing data and computer modelling, the home ranges of grizzly bear, caribou, and greater sage grouse were evaluated for detection of songbird and overall bird species, species richness, species uniqueness, and for detections of provincially and federally designated songbird species at risk. These values will also be compared between grizzly bear management areas.
This multi-scale approach will provide insight into at what scale(s) grizzly bear-songbird surrogacy is effective, simplifying land and wildlife management decision making.
1Alberta Environment and Sustainable Resource Development (2014). A Guide to Endangered and Threatened Species, and Species of Special Concern in Alberta. Version 1. Retrieved from http://aep.alberta.ca/fish-wildlife/species-at-risk/species-at-risk-publications-web-resources/documents/SpeciesAtRiskGuide-Jan-2015.pdf
2Alberta Sustainable Resource Development (2008). Alberta Grizzly Bear Recovery Plan 2008-2013. Retrieved from http://aep.alberta.ca/fish-wildlife/wildlife-management/grizzly-bear-recovery-plan/documents/GrizzlyBear2008-2013-RecoveryPlan-2008.pdf
3Caro, T. and O’Doherty, G. (1999). On the Use of Surrogate Species in Conservation Biology. Conservation Biology, 13(4), 805-814.
4Favreau, J.M., Drew, C.A, Hess, G.R., Rubino, M.J., Koch, F.H., and Eschelbach, K.A. (2006). Recommendations for assessing the effectiveness of surrogate species. Biodiversity and Conservation, 15, 3949-3969.
5Higa, M., Yamaura, Y., Senzaki, M., Koizumi, I., Takenaka, T., Masatomi, Y., Momose, K. (2016). Scale Dependency of two endangered charismatic species as biodiversity surrogates. Biodiversity and Conservation, 25(10), 1829-1841.
6Migratory Birds Convention Act, 1994 (S.C. 1994, c. 22).
7North American Bird Conservation Initiative Canada (2012). The State of Canada’s Birds. Retrieved from http://www.stateofcanadasbirds.org/State_of_Canada%27s_birds_2012.pdf
8Simberloff, D. (1998). Flagships, Umbrellas and Keystones: Is Single-Species Management Passé in the Landscape Era? Biological Conservation, 83(3), 247-257.