| Summary: | Indirect effects resulting from species sharing the same enemy can shape spatio-temporal variations in species occurrence. The strength of such effects remains poorly known in natural communities composed of species from different trophic levels interacting in heterogeneous landscapes. Benefiting from a well-known arctic vertebrate community and marked spatio-temporal variations in the density of key prey species, we examined the effects of direct predator-prey and indirect predator-mediated effects on species occurrence in the landscape. We found both positive effects of one prey (lemmings), as well as negative indirect effects of another prey (colonial nesting snow geese) on the occurrence of species (ground-nesting birds) belonging to different guilds and trophic levels but sharing a common predator (arctic fox). However, species using prey refuges available in the landscape were not or less affected by predator-mediated effects. Similarly, the smallest (a passerine) and the largest and most dangerous species (an owl) for the shared predator were not affected by these effects. Our study provides one of the rare empirical evidence of predator-mediated effects ascending the food web (i.e., negative indirect effect of an herbivore on avian predators) and underlines how habitat structure and species traits can modulate the strength of indirect effects in natural communities. The README file contains column descriptions and general information for the analyses. Funding provided by: Arctic Goose Joint Venture Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100019779 Award Number: Funding provided by: Fonds de recherche du Québec – Nature et technologies Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100003151 Award Number: Funding provided by: Indigenous and Northern Affairs Canada Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100008632 Award Number: Funding provided by: Natural Resources Canada Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100000159 Award Number: ...
|
|---|