Abstract
The nesting habitat of Northern Goshawks was analysed in Nasunogahara, Tochigi Prefecture, central Japan. The size and species of nesting trees used in 2000 or 2001 (n=36) and the microhabitat of nest site plots (0.04 ha: 11.3 m radius of each nest trees) were compared with those of randomly selected trees and the microhabitat in randomly selected plots (n=50) in the study area. Goshawks most frequently nested in Japanese Red Pine Pinus densiflora (91.7%), and did not use any broad-leaved deciduous trees, presumably because the large horizontal boughs of red pines are particularly suitable for nesting. Plots where red pines predominated (>75%) were significantly preferred. The hawks selected trees with a DBH (diameter at breast height) of more than 30 cm and avoided those with a DBH of less than 20 cm. Nest site plots had large trees with greater DBH and a greater proportion of open space than random plots, though the mean densities of trees did not differ between the nests and the random plots. The study suggests that large red pines amid open spaces for easy flight access provide suitable nesting habitat.
