Foraging ecology of black-backed woodpeckers (Picoides arcticus) in unburned eastern boreal forest stands

• Published in: Canadian journal of forest research Vol. 40; no. 5; pp. 991 - 999
• Main Authors: Tremblay, Junior A, Ibarzabal, Jacques, Savard, Jean-Pierre L
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.05.2010; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: Animal, plant and microbial ecology; bark beetles; Biological and medical sciences; Boreal forests; boring insects; coarse woody debris; Coniferous forests; Dead wood; decayed wood; diameter; Excavation; Forage; Foraging; Foraging behavior; Forest management; Forest management. Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Forestry; Forests; Fundamental and applied biological sciences. Psychology; Habitats; Insects; Methods; Nesting; Outbreaks; Picoides; Picoides arcticus; Plant growth; Plant-animal interactions; Properties; snags; Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Substrates; Telemetry; wildlife habitats; woodpeckers; Quebec; Boreal forest; Ecology; Forest stand; Forestry
• ISSN: 0045-5067; 1208-6037
• DOI: 10.1139/X10-044

Managed coniferous forest dominates much of the black-backed woodpecker’s (Picoides arcticus Swainson) breeding range. Despite this, little is known about the fine-scale foraging behaviour of this focal species in unburned managed forest stands in the absence of insect outbreaks. To investigate the foraging substrates used in such a habitat, we employed radio-telemetry to track a total of 27 black-backed woodpeckers. During two successive summers (2005–2006), 279 foraging observations were recorded, most of which were on dying trees, snags, and downed woody debris. Individuals frequently foraged by excavation, suggesting that in the absence of insect outbreaks the black-backed woodpecker forages mainly by drilling. The majority of foraging events occurred on recently dead snags with a mean dbh (±SE) of 18.3 ± 0.4 cm. Our results suggest that in unburned boreal forest stands, substrate diameter and decay class are important predictors of suitable foraging substrates for black-backed woodpeckers. We suggest that conservation efforts aimed at maintaining this dead-wood dependent cavity nesting species within the landscape, should endeavour to maintain 100 ha patches of old-growth coniferous forest. This would ensure the continuous production of a sufficient quantity of recently dead or dying trees to meet the foraging needs of this species.