Woodpecker abundance and tree use in uneven-aged managed, and unmanaged, forest in northern Maine

Abstract

We studied abundance and tree use (foraging and drumming) of the cavity-nesting woodpecker guild (7 species) in northern Maine to assess effects of uneven-aged forest management (an irregular shelterwood system) on woodpecker populations. Woodpecker abundance in managed and unmanaged hardwood stands showed no difference. Abundance in managed softwood stands was greater than in unmanaged softwood stands. Woodpeckers preferred (use greater than availability) to forage and drum on large-diameter (>30 cm) living trees (hardwood and softwood). Living trees used by woodpeckers, however, were commonly in a state of decline, with characteristics such as fungal conks, broken limbs, and broken tops. When dead trees were used, woodpeckers preferred large-diameter, recently-dead trees. Although we identified tree types preferred by woodpeckers, the abundance of preferred trees in a stand was a poor predictor of woodpecker abundance. The uneven-aged management we studied did not reduce the number of preferred trees or snags to a level that affected woodpecker abundance.