Avian use of early-successional boreal forests in the postbreeding period

Abstract

ABSTRACT. The postbreeding period is critical for many forest birds and especially for juveniles, which must learn to forage on their own before the fall migration. During this period, many birds of the boreal forest are found in early-successional stands (ESS), where fruit abundance is typically high. Boreal forest birds may use ESS to exploit fruit or for reasons other than access to fruit, namely to forage along forest edges or simply to transit through clearcuts between patches of mature forest. We tested whether frugivory, edge use, and transit through small (<65 ha) clearcuts between mature-forest patches accounted for bird abundance in ESS in a boreal forest of Quebec during the summers 2007 and 2008. Fifteen of the 33 species captured in ESS were postbreeding frugivores. Removal of all fruits from Sambucus racemosa, a dominant fruiting plant, within 10 m of mist-netting sites reduced the number of frugivores captured by 45% but did not affect nonfrugivores. Numbers of birds captured were independe...