Magellanic Woodpecker (Campephilus magellanicus) tree selection in subantartic forest at Omora on Navarino Island, Chile

IPPI, S.; HAGELIN, J.; ROZZI, R.; ARAVENA, J. C.

Puyehue, Chile

Congreso; VII Congreso de Ornitología Neotropical; 2003

Neotropical Ornithological Society

The Magellanic Woodpecker (Campephilus magellanicus) is the only woodpecker species that reaches the austral extreme of the Americas dominated by the evergreen Nothofagus betuloides forests. This woodpecker might play a major roles as the main cavity maker. However, its habitat use in these forests is still unknown. We searched for Magellanic Woodpecker cavities in different forest types dominated by Nothofagus betuloides, N. pumilio, N. antarctica and Drymis winterii in the low forests the Omora Ethonobotanical Park (55°S). At each cavity site we measured: i) percent of understory and canopy cover, ii) average shrub and canopy height, iii) slope, iv) tree species, v) tree height, vi)DBH, vii) height of first limb of the tree and of first limb above hole, viii) hole height, ix) hole orientation, x) distance to nearest tree (˃8.0cm DBH), and its DBH. Same variables were measured at a random tree 100m from the roost-tree. A total of 18 roost-trees were found: 5 in N. betuloides and 13 in N. pumilio. No cavities were found in N. antarctica and D. winteri. Average roost height was 7.67 ± 1.7m. Cavities were located in trees  that differed from random trees in the same habitats with respecto to the variables measured (chi-square: 25.31, p=0.06, n=18). Cavity-trees were significantly taller than random-trees, and had a minimum DBH of 43cm. Holes tended to be found on the east side of trunks. Our results coincide with previous sutdies finding that C. magellanicus requires large trees, and nests only in Nothofagus. We report for the first time N. betuloides as roost/nest-tree. Forests dominated by this species are subject to milder microclimatic conditions than deciduous forests, and might offer favoralbe habitat during winter. Cavity orientation toward the east might provide protection from west prevailing winds, allowing C. magellanicus to inhabit the southernmost forests of the world.