(1) Whistling Swans, Cygnus columbianus jankowskii, have been wintering at Lake Suwa in central Honshu since 1974. I have made individual recognition of the swans by their bill patterns. The development of the bill pattern from cygnet (first winter) to subadult was described. The adult and sub-adult bill patterns of the Lake Suwa swans were classified as either type-a ("darky" of EVANS, 1977) or type-b ("yellowneb" and "pennyface"). Seven birds have the type-a and 5 birds have type-b bill patterns.
(2) The bill pattern of the cygnets developed rather rapidly and the adult bill pattern could be anticipated from the cygnet bill pattern after March. However, because the post nareal area remains to be developed in spring, I cannot be sure of the bill pattern of the second winter and after until I actually observe the bird in the next winter. Nevertheless it was quite possible to tell which individual is in its second winter.
(3) As a result of individual recognition, it has become evident that a pair of parents are wintering at Lake Suwa every winter with their cygnets of the year. Incidentally, the offspring of the pair increased in the first six years of my observation but decreased thereafter.
(4) The family group consists of the parents and the cygnets of the year. However, the subadults of the second winter occasionally joined the family group. In one instance a subadult bird was often observed with the family group up to its fourth winter. Subadults may form a subadult group and winter together with the parents (family group). Other cygnet and 2nd winter subadults disappeared from Lake Suwa, indicating that many of the second and third winter birds would become completely independent of the parents and winter elsewhere.
(5) At Lake Suwa the female usually took charge of the family group and selected the feeding and roosting places. The male acted as the guard of the group while they were feeding. The division of labor between the parents was more or less evident.
(6) The arrival of the subadult group was usually not the same day as the family group. It has been more usual that the subadult group was feeding and roosting separately from the family group. However, the subadults sometimes joined the family group and often they were not too distant from the family group, that is, the subadults were not in the family group but they remained rather close to the latter. Some of the subadults appeared to be paired, while the others were single. As a rule, the subadults were behaving in a rather loose group.

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Hirundo rustica has been observed in Taiki, southern Tokachi District since 1972, although this species is rare in other areas in Tokachi. Seven cases of breeding were found during a period between 1972 and 1981. These are the first breeding records of this species from Tokachi District. Young fledged successfully from 5 nests; one nest was destroyed before egg-laying and the other was destroyed before the chiks fledged. Two pairs had second broods. The habitat of the breeding place consists of ranches surrounded with pastures and cultivated fields along the Monbetsu and Nakanokawa rivers. All nests were located on the ceilings of cattle barns. The mean clutch size was 3.8 (3.5 for the first and 4.5 for the second brood). The mean brood size was 3.5 (3.3 for the first and 4.0 for the second brood). Incubation period was 13 to 14 days. Young fledged at 17 to 22 days after hatching.

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