Home range and habitat use by Magellanic woodpeckers in an old-growth forest

OJEDA, V; CHAZARRETA, LAURA

CANADIAN JOURNAL OF FOREST RESEARCH

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2014 vol. 44 p. 1265 - 1273

0045-5067

The Magellanic woodpecker is a large vulnerable species exhibiting geographic range retraction. We analyzed the size and location of forest areas used by these woodpeckers in consecutive years (2010-2012) as related to habitat characteristics, in old-growth lenga (Nothofagus pumilio) forest of Argentine Patagonia. Woodpeckers were tracked during the post-breeding season; forest features were evaluated in plots within territories. Woodpecker density was 1.01 territories /100 ha. The resident population apparently saturates the forest available in the study site; hence, territorial disputes were frecuent between all pairs of adjacent families. Families used 39.3 ± 13.6 ha during the post-reproductive season, and 63.2 ± 12.3 ha across the three seasons, with interannual variability in both location and size of the areas used. Abundance of large live trees and coarse woody debris were correlated with smaller, presumably high quality, home ranges. Other forest attributes that are important in woodpecker habitat studies (e.g. snag density) had little relationship with home-range size, but the high availability of certain resources in old-growth forests may mask their potential importance in other situations. Our results show that Magellanic woodpeckers family groups require a minimum of 100 ha in old-growth forest habitat; thus, forest patches in less favorable forest conditions (e.g., younger, managed, fragmented, mixed forests) should probably be much larger in order to be suitable for a resident pair or family. This would be a provisional minimum threshold to be used in management decisions involving the forests of Patagonia, until alternative figures are derived from studies across multiple forest types.