This is the 4th year report of bird census in the Imperial Palace during April 1968 and March 1969. Out of 74 species recorded since 1965, 48 species (52 species in 1967) were found with additions of only one species and one hybrid (Mallard × Sptbilled Duck). The Palace area includes ponds with summer heronries and winter duck flocks (mostly Spotbilled Duck and Mandarine Duck) and average number of species and birds recorded per one census was 23.6 species (23.8 in 1967). and 481.0 birds (641.2 in 1967). The census was made monthly (14 times in all) and usually 10.00-12.00a.m. along the same 4km route. Previous reports are in Nos. 25, 27, 29 of this journal.
Based on material kindly given to the author from late Mr. Jicho Ishizawa, stomach contents of Japanese woodpeckers, formerly collected by him, are analysed. The materials are from 8 species 12 spp. and subspp., 165 individuals of Woodpeckers collected during 1923-1941. They are: Picus canus jessoensis (5), P. awokera awokera (49), Sapheopipo noguchii (2), Dendrocopos major japonicas (14), D. m. hondoensis (58), D. leucotos subcirris (4), D. l. stejnegeri (7), D. l. owstoni (2), D. kizuki seebohmi (1), D. k. nippon (16), Dryocopus martius (5) and Jynx torquilla japonica (8). The result is summarized in the following table: It is to be noted that although ants are general foods especially preferred by Picus canus, P. awokera, Dendrocopos major hondoensis, D. leucotos and Jynx torquilla, much vegetable foods are taken by P. awokera, Saphaeopipo noguchii and D. major.
During the period covered by this report, April 1, 1967 to March 31, 1968, 30, 606 birds of 136 species were ringed at more than 30 localities in 23 prefectures of Japan. The number of birds ringed and released is shown in Table 1. Recoveries of birds ringed by Yamashina Institute for Ornithology and its cooperators totaled 114 birds of 23 species of which 28 individuals of 9 species were reported from foreign countries. Those recovered at, or in close proximity to, where banded and within one year after ringed, are not described here. Besides that, those of Motacilla alba and Delicon urbica recovered at ringing places more than year after ringed are also excluded. They will be described later in other papers. The recoveries of birds ringed by the ringing team of the Forest Experiment Station, Dept. of Agriculture and Forestry. are mentioned in appendix. During the period, recoveries of 28 birds of 9 species ringed abroad were reported from the interior Japan.
Seasonal distribution and ecology of migrant bird populations were studied by mist-netting and banding chiefly in Kyunggi-do, Korea, January-November 1968. A total of 60 species 6, 245 birds were banded, with recoveries of 8 species, 25 birds out of those banded in 1968 and previous years. Recoveries from abroad were 2 species, 4 birds. Two hundred and eight House Swallows returned from 1968 and previous year banding. Records of 8 rare species, Porzana fusca, Ardeola ibis, Egretta garzetta, Egretta intermedia, Fulica atra, Cygnus olor, Prunella collaris and Gallicrex cinerea, and one species, Lanius excubitor bianchii, new to Korea, are given with notes on banding and collection. Twelve heronries are described (Fig. 1).
New specimen records of Aquila heliaca (Iriomote I.), Aegypius monachus (Miyako I.), Ciconia ciconia (Okinawa I.), Diomedea immutabilis (Kume I.) and Grus vipio (Okinawa I.) (by Takara), and 65 sepecies to be added as specimen or sight records to avifaunae of islands of the Ryu Kyu Chain (Okinawa to Yonaguni), as the result of field and specimen survey during January 12 and February 17, 1969 (by Kuroda), are reported. Brief notes on status of a few species are added. Anthus cervinus (Okinawa to Yonaguni), Motacilla flava taivana (Yonaguni) and Phylloscopus inornata (Okinawa to Yonaguni), for example, were common wintering species, the second species having been found foraging in association with grazing cows. Turdus pallidus was very common on all islands except Iriomote. Endemic Dendrocygna javanica and Spilornis cheela (Saphaeopipo noguchii has been treated in other article) are decreasing owing to increasing hunting. Butastur indicus which concentrate on Miyako I. on migration in great numbers had been so much caught by islanders by special perching devise that has greatly decreased recently. The search for Halcyon miyakoensis was made based on remour of its rediscovery but with no definite evidence, though further care should be kept on this species. Only Miyako I. is flat possibly with stable air conditions and this may be a reason why rather many atragglers of large gliding birds, including hawk, eagle, crane or stork, have been found and caught. Rarities are often shot against game law and protection of native as well as these migrants is needed.
The pre-war population of Collared Turtle Dove, Streptopelia decaocto, occupied a rather restricted area, particularly around Koshigaya, in Saitama and parts of adjacent prefectures. After the war, since 1945, it was recklessly shot to the danger of near extinction. In 1948, Udagawa estimated its number as about 60 birds within an area of 2km radius, and it may have been still more reduced later, perhaps to less than 20. However, soon it became protected as a natural monument and the 'prefectural bird' and then showed a steady increase in number. After 20 years, the author made 21 population censuses by random search method during a period of 1967, Oct. and 1968, June (with 10 more supplemental post-breeding counts of July to Oct., 1968). Its number could be totalized as 580 birds. But, if 86 singing males recorded are regarded as paired breeders, 666 birds may be more accurate. Moreover, when the result of the census made in 1966 by local middle school biology group within its main populated area is considered, the total population may have been at the least 700 birds in 1968. This means about 12 times increase after 20 years. The area of population range was confirmed as 90km2 within the total area of 146km2 censused, and this is about 7 times spread from the original range in 1948. There are some concentrated areas in the main population range where the density is up to 15 birds/km2 but in the peripheral areas of recent range expansion, the density is more or less 1-2 birds/km2, the average being 6.4 birds/km2 within the total population range. The population counts of main (not total) populated areas had been made in 1959 (141 birds), 1961 (206 birds), 1963 (193 birds), 1966-67 (399 birds) and 1966 (552 birds), by Koshigaya Nishi Middle School and by Mr. Kosugi. Considering these data, a population growth curve is presented.