The present paper deals with the role of fruit-eating birds as the transporters of tree seeds, from the point of view of tree nursing in northern Hokkaido. Ornithochoryl, or seeds dispersal of trees and shrubs by birds, is a very important factor in the dispersal of plants. Fruits are favorable foods for many species of birds, and birds transport the fruit's seeds to another locality for germination and establishment. The seeds of juicy fruits (e.g., drupe, berry, hesperidium, pome, etaerio, cynarrhodium, etc.) are thus dispersed by birds in the way of endozoochoryl, since the juicy part of fruit or pericarp, especially mesocarp, is digested; but the seed is not, or can not be digested in the digestive tract of a bird (Figs. 1 and 3). In the correlation of birds and juicy fruits, the pericarp has evolved in size, color, taste, etc. to be eaten by birds, and the seed coat, or shell (endocarp) of drupe, may have evolved in hardness not to be digested (Fig. 4). This hypothesis of the hardening of seed coat may be supported by the data of germination in nursing practices. Seeds of juicy fruits germinate generally in the next spring of sowing (Table 1). To soften the hard coat for rapid germination, we use knife, enzyme of bacteria, sulfuric acid, hydrogen peroxide, boiling water, etc; or we pick young fruits with greenish epicarp and uncompletely hardened seed coat (Fig. 5), and sow seeds without pericarp immediately after picking. Fruit-eating birds soften the hard coat, as we do in nurseries. It is pointed out that the hardened coat of seeds of juicy fruits is not convenient for tree nursing but indispensable for ornithochoryl.
The following two speices were observed after a summer typhoon in 1975. 1. An immature Red-footed Booby, Sula sula rubripes, was found exhausted at Yokohama Port, Tokyo Bay on 27th August after the typhoon No. 6 (Fig. 1). This is the third record of this species in Honshu. 2. Two immature Black Terns, Sterna nigra, were discovered at the estuary of Sagami River, Sagami Bay on 24th August (Fig. 2). This is the second record of this species in Japan. The birds were seen with two Roseate Terns, Sterna dougallii, and many Little Terns, Sterna albifrons, and Common Terns, Sterna hirundo. Other interesting sea-birds collected or seeing at the same time (23rd August) in the estuary of Sagami River, were an immature Bonin Petrel, Pterodroma hypoleuca hypoleuca, and an immature Sooty Tern, Sterna fuscata. At the time of the observations there were strong southerly winds in Sagami Bay.
The author reported the breeding of Lanius cristatus lucionensis in Kumamoto Prefecture, Kyushu. During the period from 1971-1976, 14 nests were found in the urban areas of Kumamoto and Yamaga Cities (Table 1). These nests were found on trees at the height 7-18 meters (7-10 meters in most cases) above the ground. The bird prefers more or less open places with trees, and roadside trees have often been chosen as nesting tree. Egg lying season ranges from early May to early July. The breeding from nest construction to fledging of young is estimated to require about 44 days. The clutch size varies from 3 to 6. but 4 appears to be normal.
An adult bird of Oceandroma castro was captured on Oct, 26, 1975, at the Hukushimagata Bird Station, Toyosaka City, Niigata Prefecture.This is the first record of occurrence of this species on the Japan Sea coast of Honshu.