Bird investigation in Hokkaido (1965)

Abstract

In May and June, 1965, the author made five bird surveys in less known parts of Hokkaido. These are reported here under the headings: 1. Notes on birds along Shiretoko Peninsula (May), 2. Sea-bird survey of Kojima I., off Matsumae (May), 3. Observations of birds of Rishiri I. (June), 4. Bird survey of Cape Esan (May, June) and 5. Birds of Soya area and Rishiri. They are sea bird observations (pelagic census and breeding colonies) and notes on land birds.1. Along Shiretoko peninsula, sea bird colonies were observed from ship at some distance. The main colony was on the west-side cliffs at Iwaobetsu chiefly consisting of some hundreds of Larus schistisagus and Phalacrocorax capillatus with Ph. pelagicus and Cepphus carbo, etc. There were a few other smaller ones but they could not be observed at close range. According to local observer, Mr. Yoshida, there appears to be some colonies of Uria aalge, Lunda cirrhata, Cerorhinca monocerata, and breeding of Fratercula and Brachyramphus marmoratus, possibly also Phalacrocorax urile is suggestive. Summer records so far known for Brachyramphus are listed and two birds were encountered this time. A flock of scores of Larus crassirostris were observed near the tip of the peninsula but the breeding was not confirmed. According to Yoshida, he saw chicks of Histrionicus with an adult bird in June, 1963. A White-tailed Sea Eagle was seen on a pack ice with some Larus schistisagus; it breeds at several places of the peninsula. Two Japanese Robins, Erithacus akahige, were unexpectedly found at rocky tip of the peninsula where there were no vegetations and some snow was remaining. Offshore census of sea birds is given in tables.2. Kojima I. is situated in 139°50'E, 41°20'N, 20km. WSW of Matsumae, the southwesternmost tip of Hokkaido. It is a small volcanic island with a coastal line of about 7km., surrounded by steep cliffs and inhabited only by lighthouse keeper family. The breeding species consisted of Larus crassirostris, Uria aalge, Cerorhinca monocerata, Cepphus carbo and Phalacrocorax capillatus, as on Teuri I. (Kuroda, 1963). Many nest burrows of Cerorhinca were found excavated (by a dog of the lighthouse) and this puffin was apparently decreasing (but increasing at Teuri I.) judging from remains of nests on which grasses were already growing. Gull eggs were still being taken by fishermen and thus protection of the whole island is hoped. The time (May 14) was too early (the season was 10-14 days in retard this year) for Uria aalge which we saw only a few, but on May 31 some hundreds were seen by Mr. Saito. On the island some passerines on migration (both leaving winter bird such as Turdus naumanni and arriving summer birds such as Muscicapa narcissina were found). Scattered Cerorhinca and some flocks of Puffinus griseus and P. carneipes were seen in this sea area and a huge migrating flock of about 3, 000 birds (probably of the latter species) were flying northwestward off Cape Shirakami in an endless line. A flock of 300 birds of this species (definitely identified) had been observed on May 7 all making west the Tsugaru Strait.3. Rishiri and Rebun Is. (See also 5.) situated at a little north of 45N°, west of Wakkanai, northern end of Hokkaido, were visited June 7-9, staying on Rishiri. Cerorhinca was found scattered on the sea between Wakkanai and the islands and many were non-breeding birds without the bill-nob. A small number of Puffinus tenuirostris was seen confined off Wakkanai, a great flock of about 1, 500 of P. griseus consisting of numerous small groups was making a circular movements over the sea area between Rishiri and Rebun,