High goose abundance reduces nest predation risk in a simple rodent-free high-Arctic ecosystem

• Published in: Polar biology 2018-04, Vol.41 (4), p.619-627
• Main Authors: Pedersen, Åshild Ø., Stien, Jennifer, Eidesen, Pernille B., Ims, Rolf A., Jepsen, Jane U., Stien, Audun, Tombre, Ingunn, Fuglei, Eva
• Format: Article
• Language: English
• Subjects: Abundance; Anser brachyrhynchus; Apparent competition; Aquatic birds; Archipelagoes; Arctic fox; Arctic fox V. lagopus; Artificial nest; Biomedical and Life Sciences; Branta leucopsis; Breeding; Calidris alpina; Calidris maritima; Charadrius; Ecology; Ecosystem components; Ecosystems; Endemic species; Environmental aspects; Geese; Interspecific relationships; Lagopus muta hyperborea; Life Sciences; Marine crustaceans; Matematikk og naturvitenskap: 400; Mathematics and natural scienses: 400; Microbiology; Mutualism; Nesting; Oceanography; Original Paper; Phalaropus; Pink-footed Goose; Plant Sciences; Plectrophenax nivalis; Predation; Predation (Biology); Predator; Predators; Prey; Seabirds; Species; Subsidies; Svalbard; Symbiosis; Tundra; Tundra ecology; Tundras; VDP; Vulpes lagopus; Waterfowl; Zoologiske og botaniske fag: 480; Zoology; Zoology and botany: 480
• ISSN: 0722-4060; 1432-2056; 1432-2056
• DOI: 10.1007/s00300-017-2223-z

Breeding geese are the preferred prey of the Arctic fox Vulpes lagopus in the high-Arctic Svalbard archipelago. According to the apparent competition hypothesis (ACH) , less-abundant prey species (e.g. ptarmigan, waders and small passerines) will experience higher predation rates when breeding in association with the more common prey (geese), due to spill-over predation by the shared predator. As many of these less-abundant species are endemic and/or red-listed, increased predation can have negative repercussions on their populations. We used a one-year baited artificial nest study to assess relative nest predation risk on Svalbard Rock Ptarmigan Lagopus muta hyperborea , small waders (Purple Sandpiper Calidris maritima, Dunlin Calidris alpina , plovers Charadrius spp ., and phalaropes Phalaropus spp. ) and Snow bunting Plectrophenax nivalis in two study locations contrasted by nesting density of Arctic breeding geese (Pink-footed Goose Anser brachyrhynchus and Barnacle Goose Branta leucopsis ). We predicted higher predation risk for the less-abundant species in the study location with higher goose abundance. However, we found that relative nest predation risk was lower in the study location with higher goose abundance, thus being compatible with apparent mutualism and/or prey swamping mechanisms. Our results contrast with those from more structurally complex Arctic ecosystems and suggest that allochtonous subsidies from temperate ecosystems structure the predation pattern in this high-Arctic tundra ecosystem.