Habitat modeling for the Brown Hawk Owls in urban woods of Kyoto City
Hiroshi HASHIMOTO, Kuniyuki SAWA, Yukihiro MORIMOTO, Shinya NISHIO
Abstract: Brown Hawk Owl (Ninox scutulata) is a migratory insectivorous bird
which breeds in tree cavities, and a target species for old woods in urban areas of Japan.
Population of the owl is decreasing recently because of diminishing of old woods in Japan
and also in tropical rain forests: their habitats during non-breeding season.
A habitat model using statistical methods is a good tool to answer the question how much
forest is required for conservation of a target species. We made a habitat model for the owl
using a logistic regression model. We searched for owls by examining almost every large tree
with cavities in a 25 km2 urban area in Kyoto City during the breeding season (May to July) of
2002. Fourteen trees determined to be habitats of owls and 15 trees with cavities but without
nests were found. Applying logistic regression analysis with the stepwise method and AIC,
the area of tree cover and the area of urbanized area within a radius of 100 m were determined
to be variables for the habitat model of the owl. From the result, at least 1.1 ha of woods
including an old tree with a cavity is necessary for conservation of the owl habitat.
Keywords: Brown Hawk Owls, birds, habitat model, urban greenery, urban woods
H. Hashimoto, K. Sawa, Y. Morimoto and S. Nishio (2004) Habitat modeling for the Brown Hawk Owls in urban woods of Kyoto City. Landscape Research Japan 67: 483-486 (in Japanese with English abstract)