The ectomorphology, maximum length of skull and teeth row length of 15 (♂9, ♀6) individuals of Sorex minutissimus collected in Sarobetsu of Northern Hokkaido in both 1997 and 1998 were compared with some known data. The present measurement values on the maximum length of skull and the hind foot length not including the claw were within the known data range. However, the some extremes of the ranges of the body weight, head and body, tail, fore foot , upper teeth row and lower teeth row length were outside the known data scope. The tail length under 34 mm and caliber under 2 mm of the maximum are useful as identification criteria of this species in Sorex.

View full abstract

[in Japanese]

View full abstract

We confirmed the chipmunk (Tamias sibiricus) was eating fruits of Polygonum sachalinense. As a result, when the chipmunk eats fruits of Polygonum sachalinense, it has been understood that the perianth piles up on the ground. This is a new observation example. Besides, it has been understood to be able to distinguish by the part which how to eat and is eaten with Tetraste bonasia and Clethrionomys rufocanus which eats Polygonum sachalinense. It is not reported that there are signs which can be clearly judged that it is chipmunk's field sign before.Therefore, this is effective as chipmunk's field sign.

View full abstract

On May 10, a 47 year old fisherman was killed and eaten by a sole, 2 year 3 month old male bear (Ursus arctos). On the following day in the same area, two women (30 and 50 years old) were out collecting edible wild plants when they were attacked and wounded by the same bear that killed the fisherman. The bear had clearly eaten the fisherman's facial, head and throat muscles, right arm, right pectoral muscles and ribs. The facts that the bear had attacked, dragged the man to a comfortable place and then ate, suggests that the bear's attacking purpose was for food. The two women had come within a few meters of the bear and were attacked by the bear when trying to flee. Both women were injured in the head region. The first woman attacked was the 50 year old woman. She fought off the attack by repeatedly beating the bear with a stick. The bear then attacked the younger woman but was astonishingly driven off when the elder woman produced a large sound with her car horn. The bear had evidently attacked the women with the purpose of repelling them from his nearby food source ; the fisherman's corpse. In the past 30 years, the incidence of bear attacks on people, other than hunters, has been limited to either sole young bears or dam with offspring. The young bears were mostly two or three years old, however in some rare cases, the bear has been four years old. The causes of these attacks may be divided into three categories, i.e. to eat, to repel or to play. The incidents mentioned above fit within these categories. In the case of the fisherman, it may have been possible for him to have safely escaped if he had repelled the attack with a hatchet that may be carried legally.

View full abstract

It was investigated in the urban forest of Akita-city in terms of tending of the forest types, that the situation of serow's utilization and the quantity of the fooding plants in a snow period. Also, to know the influence by the of serow to the Japanese cedar the situation of the fooding was checked with planted Japanese cedar. The quantity of the fooding plant decreased immediately after tending, but it is expected that the fooding plants would increase as the time passes, so it was estimated that the tending would give a stabilized environment to serow. But it is nesessaly to cousider not to do large area tending in the Querucus forest, which had much quantity of the fooding plants. Furthermore, it was conjectured that there is not substantial damage to the Japanese cedar area near the much quantity of the fooding plants area in a snow period, although it is expected that the fooding Japanese cedar of serow increases.

View full abstract

The growth pattern of the body weight and tarsus length of the nestlings of the Rufous Turtle Dove, Streptopelia orientalis Latham was analyzed. 67 nestlings, with the brood size from one to three, were obscrvcd from the natural population living in the campus of the University of Tsukuba every day from the first day to the 15th day, when is the average fledging period. Richards' growth model was fitted to the body weight and tarsus length, then allometric growth model was tested between body weight and tarsus length. The results are as follows: (1)The growth rate from the first to fifth day was larger than that from 5th to 15th day, showing the nutritional advantage of crop milk during the early growth. The growth rate was negatively correlated with the brood size, which is explained by the fact that the amount of crop milk is constant regardless of brood size. (2)The four-pointed method was applied to the Richards' growth model, resulting in the high fitting coefficient of 99.8% to both body weight and tarsus length. The results indicate that Richards' growth model can be used to the growth pattern of body weight and tarsus length of the nestlings in the Rufous Turtle Dove. (3)The relative growth coefficient of body weight to tarsus length was 2.19, 2.20, and 2.16 for the brood size from one to three, respectively, which shows strong positive allometric growth.

View full abstract

The distribution of Lacerta vivipara was investigated at fourteen sites on the Sarobetsu Wetlands from late July to late August, 1997-1998. A total of sixteen lizards were collected from eight sites of all. The mean number of collected lizards were 0.19 per 100 trap nights. They were randomly distributed in the Sarobetsu Wetlands. Sexual dimorphism was observed through the differences in tail width. They fed on small insects living in the grass and underground. Takdromus tachydromoides were collected with Lacerta vivipara at the same site.

View full abstract

The authors observed a white-spotted chaff Salvelinus leucomaenis redd in a small stream flowing into Lake Shikotsu, Hokkaido. The redd was located in the middle of a riffle with current velocity and average median gravel size being 0.4m/sec and 53mm, respectively. The spawning habitat of the white-spotted charr was different from that of Japanese charr, populations in mainland Japan, reported in the literature.

View full abstract