Observations of birds on Oshima Ooshima Island, 55 km west of Era, southern Hokkaido, was done during the period from 8 to 10 October 1990. A total of 1, 235 birds consisting of 36 species were observed. The most abundant bird was the Siskin Carduelis spinus (n=435, 35.2%). Other main species in order of decreasing were: Great Tits Parus major (n=130, 14.7%), Oriental Greenfinches Carduelis sinica (n=106, 8.6%), Rustic Buntings Emberiza rustica (n=34, 2.7%), Jungle Crows Corvus macrorhynchos (n=35, 2.8%), Temminck's Cormoramts Phalacrocorax capillatus (n=29, 2.3%), Bullfinches Pyrrhula pyrrhula (n=20, 1.6%), and Peregrine Falcons Falco peregrinus (n=18, 1.5%). As the rare bird species on this island, 16 Mandarin Ducks Aix galericulata, one Tengmalm's Owl Aegolius funereus, and one Pine Bunting Emberiza leucocephala were observed.
We observed that Japanese White-eyes Zosterops japonica sucked honey dews secreted by two species of small jumping plant-lices, Heterophylla cubana and Stenopsylla nigricornis. This is the first observation of inter-specific relationship between homopteran insects and white-eyes. Such a foraging manner might be common in White-eyes. Although honey dew of homopteran insects is not neccessary to White-eyes as nectar resource, the homopteran insects seems important as insect foods.
I observed that a Japanese White-eye Zosterops japonica sucked necter from extrafloral nectaries of the Terminalia catappa L. in the Bonin Islands. The extra-floral nectary secretes sugar water to establish the antiherbivore mutalism. In this case, the White-eye seems play as a opportunistic defender.