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Data from: Salmonid species diversity predicts salmon consumption by terrestrial wildlife

Citation

Service, Christina N. et al. (2019), Data from: Salmonid species diversity predicts salmon consumption by terrestrial wildlife, Dryad, Dataset, https://doi.org/10.5061/dryad.t474mn0

Abstract

1. Resource waves - spatial variation in resource phenology that extends feeding opportunities for mobile consumers - can affect the behaviour and productivity of recipient populations. Interspecific diversity among Pacific salmon species (Oncorhynchus spp.) creates staggered spawning events across space and time, thereby prolonging availability to terrestrial wildlife. 2. We aim to understand how such variation might influence consumption by terrestrial predators compared with resource abundance and intra- and inter- specific competition. 3. Using stable isotope analysis, we investigated how the proportion of salmon in the annual diet of male black bears (Ursus americanus; n = 405) varies with species diversity and density of spawning salmon biomass, while also accounting for competition with conspecific black and grizzly bears (U. arctos horribilis), in coastal British Columbia, Canada. 4. We found that the proportion of salmon in the annual diet of black bears increased by ≈40% in the absence of grizzly bears, but detected little effect of relative black bear density and salmon biomass density. Rather, salmon diversity had the largest positive effect on consumption. On average, increasing diversity from one salmon species to ~four (with equal biomass contributions) approximately triples the proportion of salmon in diet. 5. Given the importance of salmon to bear reproduction, this work provides early empirical support for how resource waves may increase the productivity of consumers at population and landscape scales. Accordingly, terrestrial wildlife management might consider maintaining not only salmon abundance but also diversity.

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