AVIS-IBIS

Birds of Indian Subcontinent

NEST-SITE SELECTION OF NORTHERN GOSHAWKS AND EURASIAN SPARROWHAWKS IN A FRAGMENTED LANDSCAPE IN NORTHERN JAPAN

Publication Type:Journal Article
Year of Publication:2007
Authors:Abe, F, Hasegawa, O, Kudo, T, Higashi, S
Journal:Journal of Raptor Research
Volume:41
Issue:4
Date Published:2007
ISBN Number:0892-1016
Keywords:Accipiter, Accipiter gentilis, Accipiter nisus, Accipitridae, Astur gentilis, Japan, Nisus, Passer, Passer montanus, Passeridae
Abstract:ABSTRACT We measured the characteristics of trees and sites of 14 Northern Goshawk (Accipiter gentilis) and 14 Eurasian Sparrowhawk (Accipiter nisus) nests in the Ishikari Plain of Hokkaido, Japan, where their nesting habitats were fragmented into small woodlots. We also randomly located 25 plots (0.033 ha each) in unused woodlots to compare differences between nest and random sites. Goshawks nested in a variety of trees and diameters at breast height (dbh) of nest trees were significantly larger than the mean values for all trees in the nest sites, and were similar to the largest trees in these sites. The heights of nest trees were significantly larger than the mean values of all trees in the nest sites. Goshawks nested in a variety of forest types, in proportion to their availability. The dbh and tree heights of sparrowhawk nest trees were significantly larger than the mean values of all trees in the nest sites, and were significantly smaller than the largest trees in these sites. Sparrowhawks nested only in evergreen conifers, and their nests were more likely to occur in evergreen coniferous forests than in other forest types. Diameters of nest trees were larger for goshawks than sparrowhawks, but the tree density was higher for sparrowhawks. Goshawks and sparrowhawks nesting sites were further from human habitation than random sites, but averaged only 247 and 229 m from houses, respectively.ABSTRACT We measured the characteristics of trees and sites of 14 Northern Goshawk (Accipiter gentilis) and 14 Eurasian Sparrowhawk (Accipiter nisus) nests in the Ishikari Plain of Hokkaido, Japan, where their nesting habitats were fragmented into small woodlots. We also randomly located 25 plots (0.033 ha each) in unused woodlots to compare differences between nest and random sites. Goshawks nested in a variety of trees and diameters at breast height (dbh) of nest trees were significantly larger than the mean values for all trees in the nest sites, and were similar to the largest trees in these sites. The heights of nest trees were significantly larger than the mean values of all trees in the nest sites. Goshawks nested in a variety of forest types, in proportion to their availability. The dbh and tree heights of sparrowhawk nest trees were significantly larger than the mean values of all trees in the nest sites, and were significantly smaller than the largest trees in these sites. Sparrowhawks nested only in evergreen conifers, and their nests were more likely to occur in evergreen coniferous forests than in other forest types. Diameters of nest trees were larger for goshawks than sparrowhawks, but the tree density was higher for sparrowhawks. Goshawks and sparrowhawks nesting sites were further from human habitation than random sites, but averaged only 247 and 229 m from houses, respectively.
URL:http://dx.doi.org/10.3356/0892-1016(2007)41[299:NSONGA]2.0.CO;2
Short Title:Journal of Raptor Research
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith