TY - JOUR
T1 - Intrapopulation diversity in isotopic niche over landscapes
T2 - Spatial patterns inform conservation of bear–salmon systems
AU - Adams, Megan S.
AU - Service, Christina N.
AU - Bateman, Andrew
AU - Bourbonnais, Mathieu
AU - Artelle, Kyle A.
AU - Nelson, Trisalyn
AU - Paquet, Paul C.
AU - Levi, Taal
AU - Darimont, Chris T.
N1 - Funding Information:
We are grateful to collaborate with the mentors, colleagues, and friends of the Heiltsuk, Kitasoo/Xai’xais, Nuxalk, and Wuikinuxv Nations in whose territories and with whom we work. We thank G. Mowat for data and thoughtful edits to the anuscript, and to H. Bryan for her contributions to data collection, quantitative expertise, and review of the manuscript. MSA was supported by a Mitacs Accelerate Fellowship and NSERC Industrial Postgraduate Scholarship, as well as key support from the Tula Foundation. CNS was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Vanier Fellowship and a Mitacs Accelerate Fellowship. KAA was supported by an NSERC Vanier Fellowship and a scholarship funded by the Tula Foundation. AB was supported by an NSERC postdoctoral fellowship and a Killiam postdoctoral fellowship. PCP was supported by the Wilburforce Foundation. CTD was supported by an NSERC Discovery Grant (435683) as well as the Tula, Wilburforce, Moore, andWillow Grove Foundations.
Publisher Copyright:
© 2017 Adams et al.
PY - 2017/6
Y1 - 2017/6
N2 - Intrapopulation variability in resource acquisition (i.e., niche variation) influences population dynamics, with important implications for conservation planning. Spatial analyses of niche variation within and among populations can provide relevant information about ecological associations and their subsequent management. We used stable isotope analysis and kernel-weighted regression to examine spatial patterns in a keystone consumer–resource interaction: salmon (Oncorhynchus spp.) consumption by grizzly and black bears (Ursus arctos horribilis, n = 886; and Ursus americanus, n = 557) from 1995 to 2014 in British Columbia (BC), Canada. In a region on the central coast of BC (22,000 km2), grizzly bears consumed far more salmon than black bears (median proportion of salmon in assimilated diet of 0.62 and 0.06, respectively). Males of both species consumed more salmon than females (median proportions of 0.63 and 0.57 for grizzly bears and 0.06 and 0.03 for black bears, respectively). Black bears showed considerably more spatial variation in salmon consumption than grizzlies. Protected areas on the coast captured no more habitat for bears with high-salmon diets (i.e., proportions >0.5 of total diet) than did unprotected areas. In a continental region (~692,000 km2), which included the entire contemporary range of grizzlies in BC, males had higher salmon diets than females (median proportions of 0.41 and 0.04, respectively). High-salmon diets were concentrated in coastal areas for female grizzly bears, whereas males with high-salmon diets in interior areas were restricted to areas near major salmon watersheds. To safeguard this predator–prey association that spans coastal and interior regions, conservation planners and practitioners can consider managing across ecological and jurisdictional boundaries. More broadly, our approach highlights the importance of visualizing spatial patterns of dietary niche variation within populations to characterize ecological associations and inform management.
AB - Intrapopulation variability in resource acquisition (i.e., niche variation) influences population dynamics, with important implications for conservation planning. Spatial analyses of niche variation within and among populations can provide relevant information about ecological associations and their subsequent management. We used stable isotope analysis and kernel-weighted regression to examine spatial patterns in a keystone consumer–resource interaction: salmon (Oncorhynchus spp.) consumption by grizzly and black bears (Ursus arctos horribilis, n = 886; and Ursus americanus, n = 557) from 1995 to 2014 in British Columbia (BC), Canada. In a region on the central coast of BC (22,000 km2), grizzly bears consumed far more salmon than black bears (median proportion of salmon in assimilated diet of 0.62 and 0.06, respectively). Males of both species consumed more salmon than females (median proportions of 0.63 and 0.57 for grizzly bears and 0.06 and 0.03 for black bears, respectively). Black bears showed considerably more spatial variation in salmon consumption than grizzlies. Protected areas on the coast captured no more habitat for bears with high-salmon diets (i.e., proportions >0.5 of total diet) than did unprotected areas. In a continental region (~692,000 km2), which included the entire contemporary range of grizzlies in BC, males had higher salmon diets than females (median proportions of 0.41 and 0.04, respectively). High-salmon diets were concentrated in coastal areas for female grizzly bears, whereas males with high-salmon diets in interior areas were restricted to areas near major salmon watersheds. To safeguard this predator–prey association that spans coastal and interior regions, conservation planners and practitioners can consider managing across ecological and jurisdictional boundaries. More broadly, our approach highlights the importance of visualizing spatial patterns of dietary niche variation within populations to characterize ecological associations and inform management.
KW - Bears
KW - Dietary niche
KW - Geographic information systems
KW - Isoscapes
KW - Kernel-weighted regression
KW - Oncorhynchus
KW - Predator–prey systems
KW - Salmon
KW - Stable isotope analysis
KW - Ursus.
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U2 - 10.1002/ecs2.1843
DO - 10.1002/ecs2.1843
M3 - Article
AN - SCOPUS:85021206823
SN - 2150-8925
VL - 8
JO - Ecosphere
JF - Ecosphere
IS - 6
M1 - e01843
ER -