Abstract Old-growth forests are optimal habitats for many woodpeckers, which are often themselves excellent indicators of deadwood-associated biodiversity. Old-growth forests are, however, heterogeneous ecosystems in terms of structure, composition, and deadwood characteristics, thus implying a varied use of these forests by woodpeckers. In boreal landscapes, old-growth stands are threatened by forest harvesting; however, there is little information in regard to the consequences for biodiversity with the loss of specific types of old-growth forests. This study aimed to assess how the black-backed woodpecker (Picoides arcticus), a biodiversity indicator species associated with old-growth forest attributes, uses different types of old-growth forests for its foraging needs. We identified woodpecker foraging marks in 24 boreal old-growth forest stands in eastern Canada that were dominated by black spruce (Picea mariana), located within the home range of eight black-backed woodpeckers. We identified the various old-growth forest types using a typology based on the structural attributes of old-growth stands. We classified the sampled stands into four old-growth forest types, corresponding to different successional stages (recent or old, relative to the onset of the old-growth stage), composition (pure black spruce or mixed black spruce–balsam fir [Abies balsamea]), and productivity (ongoing paludification or not). The black-backed woodpecker foraged in all types of old-growth forests, but favored dense old-growth forests that were not paludified and that showed a high temporal continuity (i.e., old-growth dynamics probably started more than a century ago). The temporal continuity of the old-growth state allows for the continuous supply of large, slightly decayed snags, the preferred foraging substrates of the black-backed woodpecker. The old-growth forest type most favored by this woodpecker is, however, also the forest type most often targeted first by logging operations. Protecting the biodiversity associated with recent deadwood in managed areas thus requires maintaining a sufficient area and density of dense, old-growth black spruce-dominated forests in managed areas.

Le Québec offre un potentiel considérable pour le développement de l’industrie éolienne. Cette industrie peut être à l’origine de mortalités chez les rapaces et pourrait affecter certaines espèces vulnérables comme le faucon pèlerin. De 2008 à 2010, nous avons comparé l’utilisation de 5 types de milieux par 10 femelles nicheuses de faucon pèlerin dans le Québec méridional, afin de déterminer ceux à favoriser pour l’implantation de parcs éoliens. Les milieux les moins utilisés par les femelles étaient ceux considérés comme diminuant les risques de collision avec les éoliennes. Après l’envol des fauconneaux, les femelles parcouraient de plus grandes distances que lorsque les fauconneaux étaient confinés au nid. À cette période, 90 % des localisations télémétriques dans les cultures de maïs et de soya ont été enregistrées à l’intérieur d’un rayon de 8,3 km d’un nid, comparativement à un rayon de 15,9 km dans les autres cultures. Aussi, les femelles avaient moins de chances d’utiliser les cultures de maïs et de soya que les autres cultures et les milieux non propices pour la chasse. Nos résultats permettent de faire des recommandations quant à la localisation de projets éoliens, en termes de milieux à favoriser et de distances à respecter, afin de minimiser les risques de collision du faucon pèlerin.

Intensive agriculture, as is typical of corn and soybean production, may be responsible for declines in the abundance and diversity of farmland birds. In Quebec, the transition to intensive crops is evidenced by marked increases of corn and soybean fields. From 2008 to 2010, we used satellite telemetry to study use of corn (Zea mays) and soybean (Glycine max) fields, other farmlands, wetlands, urban areas, and other habitats by 10 female Peregrine Falcons (Falco peregrinus) of the anatum–tundrius complex, a taxon of “special concern” in Canada. We monitored females during the nesting season, from hatching of eggs to independence of young, but before the young dispersed away from the nest site. Adult females were less likely to use corn and soybean fields than the “other farmlands” and “other habitats” categories during the nestling stage and the first month after young fledged. Once young fledged, other farmlands and urban areas were more likely to be used than the “other habitats” category when females were hunting in the areas that were farthest from the nest. The expansion of corn and soybean fields in the Quebec agricultural landscape has occurred to the detriment of other crops and may contribute to the decline in quality of hunting habitat of Peregrine Falcons and other avian top predators.