Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

Black-backed woodpeckers (Picoides arcticus) may depend on recently burned forest patches to maintain viable population levels. We wanted to determine how these habitats are colonized by this species and by which age classes. Data collected at the Observatoire d'oiseaux de Tadoussac (situated on the north shore of the St. Lawrence River (Québec, Canada)) suggest that an important movement of juveniles occurs during the autumn. It was therefore hypothesized that in the year following fire, burned forest sites would be colonized by a higher percentage of juvenile birds than intact mature stands. In accordance to this hypothesis, there was a difference in woodpecker age structure between the two habitat types (χ2 = 9.43, df = 2, P = 0.0088, n = 186). However, differences are mainly explained by the higher number of third calendar year birds at burned forest sites, suggesting that a part of the colonization occurs in the same year as the fire by second year birds, rather than by juveniles during the autumn.