Experimental and field evidence indicate that islet-nesting tundra birds experience reduced nest predation and benefit indirectly from high snow goose densities

Beaudoin, Marylou ORCID: https://orcid.org/0009-0001-7731-8995, Beardsell, Andréanne ORCID: https://orcid.org/0000-0001-8689-3177, Duchesne, Éliane ORCID: https://orcid.org/0000-0003-2597-3442, Corbeil-Robitaille, Madeleine-Zoé ORCID: https://orcid.org/0000-0002-8324-1381, Legagneux, Pierre ORCID: https://orcid.org/0000-0002-6366-0554, Berteaux, Dominique ORCID: https://orcid.org/0000-0003-2728-5985 et Bêty, Joël ORCID: https://orcid.org/0000-0002-8775-6411 (2026). Experimental and field evidence indicate that islet-nesting tundra birds experience reduced nest predation and benefit indirectly from high snow goose densities. Oikos (e12250).

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Résumé

Landscape features can shape the occurrence and strength of predator–prey interactions by influencing predation risk and prey distribution. In the High Arctic, some bird species select nesting sites with physical features that impede access for their main terrestrial predator, the Arctic fox. We investigated how nest microhabitat characteristics and prey availability modulate nest survival in tundra birds that select pond and lake islets as breeding sites. Over four summers, we analyzed survival of 132 cackling goose and 55 glaucous gull nests located on islets or pond and lake shores within a 150-km2 area encompassing a snow goose colony on Bylot Island, Nunavut, Canada. Over three years, we also assessed the effect of microhabitat on predation risk using artificial nests. We found that islets act as partial prey refuges, with higher nest survival on islets than on pond and lake shores. Nest survival generally increased with islet distance from shore, but we found little evidence of this effect for cackling geese and glaucous gulls, which rarely nested on islets near shore. Moreover, water depth surrounding islets had little to no influence on any nest type. Nest survival on islets was much lower in a year with relatively low snow goose nest density, suggesting that geese may confer a short-term positive indirect effect on other bird species nesting on islets within or near the main goose nesting area. Since the Arctic fox was virtually the sole predator of artificial nests, our findings suggest that annual variation in nest survival on islets was driven by a shift in fox foraging behavior in response to changes in prey availability across the landscape. Our study, which integrates multi-year monitoring and field experiments, highlights the interplay between microhabitat selection and predator–multi-prey dynamics in the Arctic tundra.

Type de document :	Article
Validation par les pairs :	Oui
Mots-clés :	Expérience sur les nids artificiels ; Branta hutchinsii ; Grand Arctique ; Interactions indirectes prédateur-proie ; Larus hyperboreus ; Refuges naturels / Artificial nest experiment ; Branta hutchinsii ; High Arctic ; Indirect predator–prey interactions ; Larus hyperboreus ; Natural refuges .
Départements et unités départementales :	Département de biologie, chimie et géographie
Date de dépôt :	21 sept. 2026 18:38
Dernière modification :	06 oct. 2026 15:41
URI :	https://semaphore.uqar.ca/id/eprint/3640