Abstract
Color-ring banding of Great Cormorants Phalacrocoax carbo in Japan began in 1975. The first and second reports on this research were issued respectively in 1983 and 2000. This report summarizes the results for 2000 to 2007.
Banding was implemented primarily during the breeding season, from March through May, at sixteen colonies. Most of these were on the Pacific Ocean side of Honshu Island, but several were on the Japan Sea side. A total of 4,882 cormorants were banded between March 3, 2001 and December 14, 2007. Of these, the overwhelming majority (4,824) were chicks that had not yet fledged. In the past, only fragmentary data was obtained from visual confirmations and recaptures of banded cormorants, especially with regard to long-range movements. With the population of cormorants expanding, however, an understanding of their movement patterns has become even more essential. During this most recent period, the number of birds banded, as well as the number of colonies targeted, more than tripled compared to that of the previous period.
In the future, cormorant colonies in which the nests are low enough to allow access to banding research must beprotected. In addition, there is a need for technological improvements in the color bands themselves.
