Ducklings of Spotbill Ducks that this report treated were incubated from eggs collected out of the wild nests, and were being raised with the commercial chick feed for 25 weeks (the experimental raising period) at Akita Prefectural College of Agriculture in 1976. Body weight of them was Weighed at hatch and every week. Using above data, twelve sets of three figures of average body weight are prepared, which arbitrarily selected from the initial, middle and final period of the experimental raising period (as an example, 0 week of age <at hatch> for the initial period : 6 for the middle period : 17 for the final period, etc). The Growth pattern of body weight for spotbill ducks is made clear by applying to the three points method of the Richards' Growth Curve Model. The fitness regarding every equation estimated from previous procedure is determined by the determination coefficient (R^2 value). (1) The growth pattern in spotbill ducks' ducklings shows high and rapid growing during the initial raising period. The age of week at the inflection point is 4.36 for male, and 3.76 for female, respectively, and both figures approximate to ones in ducks ("Peking" breed from Mainland China). (2) The shape parameter m shown the highest determination coefficient R^2 is 1.1 (R^2=99.74) for male at the age combination 1 : 8 : 19 among the twelve sets, and 0.8 (R^2=99.40) for female at 1 : 9 : 20, respectively. Therefore, the growth pattern in spotbill ducks for male approaches to the Gompertz curve, and for female, seems to be a transitional pattern from the Gompertz curve. (3) The relationship between the shape parameter m and the determination coefficient (R^2) shows one specific curve for male and female respectively, as well as ones of ducks and chickens.

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The Jay Garrulus glandarius brandtii was surveyed along one to three 2-km transects, totaling of 401 transects, situated in 358 quadrats (5 km x 5 km) in central and south-eastern Hokkaido from late April to mid-July, 1976-1996. Based on the line transect survey data, the records from literature and ones in previous surveys, the Jay occurred in various types of forests from low altitude to 800m above sea level of mountainous areas such as Hidaka Mountains, Daisetsu Mountains and Akan National Park. Of 401 transects surveyed, the Jay was recorded in 50% of ever-green coniferous forests, 35% of mixed forests, 34% of deciduous broad-leaved forests, 28% of larch plantations, 19% of agricultural lands with wood and 7% of agricultural lands. Any Jay was not observed in Pinus pumila forests and the residential areas. Of corvid birds of Hokkaido, the Jay is regarded as a species depending on wooded habitats.

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The breeding sites and the number of egg masses of Hynobius retardatus and Rana pirica were surveyed in 755ha of the northeast area of Nopporo Natural Forest Park, Hokkaido Japan. There were 53 breeding sites of Hynobius retardatus, and the total number of egg masses was 788. While the sites of Rana pirica were 24, there were 398 in total. Among these respective breeding sites, 17 sites were used by both species. Hynobius retardatus began laying eggs when the water temperatuer was between 7 and 8℃, and increased noticeably when the water temperature reached 10℃. On the other hand, Rana pirica began laying eggs at 10℃C, and egg laying increased noticeably when the water temperature reached 12℃. My research indicates that both species instinctively return to the same breeding sites every breeding season. In order to further research the breeding dynamics of these two species, it is useful to record number of egg masses and breeding sites of both species.

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Twenty-six (2 male and 24 female) adult Ixodes persulcatus were collected from one Mustela sibirica which had died in Nopporo Forest Park, Hokkaido, Japan. To my knowledge, this in the first record of Ixodes persulcatus being collected from M. sibirica in Japan.

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As a zoogeographical research, an analysis was made on the parasitic nematode fauna of the Japanese Microtinae and Murinae (Mammalia: Rodentia: Muridae), viz., Clethrionomys rufocanus bedfordiae, C. rutilus mikado, C. rex, Eothenomys andersoni, E. smithii, Microtus montebelli, Apodemus speciosus, A. argenteus and A. peninsulae. A total of 3113 individuals were examined, and 32 nematode species were obtained. Among these nematodes, the speciation and geographical distribution of the Heligmosomoides (Heligmosomidae: Strongylida) were discussed in regard to the fossil records of host mammals and the geological record of the Japanese archipelago. It is considered that H. desportesi was derived from the central part of the Eurasian Continent in the Early Pleistocene and H. kurilensis was derived from Siberia in the Middle Pleistocene. H. neopolygyrus which occurrs in the eastern part of the Eurasian Continent migrated via northern land bridges in the Wurm Glacial Ages. Hence, the formation of parasitic nematode fauna of an endemic rodent group was related to the environment and to the mammalian fauna of the pre-Japanese archipelago in the Pleistocene.

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