The Tree Creeper Certhia familiaris populations were censused along one to three 2-km transects (a total of 827) situated in 743 quadrats (5×5 km), in central and south-eastern Hokkaido from late April to late June, 1976-2006. Tree Creepers occurred mainly in woodlands, 118 quadrats (16%) and 125 transects (15%). The occurrence frequencies were 53% in ever-green coniferous forests, 29% in mixed forests, 40% in broad leaved forests, 18% in Larix plantations, 5% in agricultural lands with woods and 0.4% in agricultural lands. Tree Creepers did not occur in Pinus pumila forests and residential areas, They occurred evenly from low altitudes to 1,000 m above sea level and there is no difference in occurrence frequencies between the western and eastern areas of Daisetus and Hidaka Mountains. There was no relationship between occurrence frequency and warmth index. The numbers of birds (mean±SD) counted per 2-km transect were 0.5±0.7 in ever-green coniferous forests, 0.3±0.7 in mixed forests, 0.3±0.5 in deciduous broadleaved forests, 0.2±0.4 in Larix plantations.

View full abstract

Surveys of bats were performed in windbreak forests located in agricultural areas in Obihiro City, Hokkaido, during the summers of 2001 to 2004. A total of 10 bat species, including Myotis macrodactylus, Myotis daubentonii, Myotis gracilis, Myotis frater, Eptesicus nilssonii, Nyctalus aviator, Vespertilio sinensis, Plecotus auritus, Murina hilgendorfi, and Murina ussuriensis were caught using mist nets. These windbreak forests, which were relatively narrow 55-75 meters in width and lacking biodiversity, such as a monoculture of Quercus dentata or planted forests of Larix leptolepis, are unfavorable as habitats for bats for making roosts, supporting breeding colonies, or as feeding grounds. Nevertheless, a number of bat species were caught in these forests, suggesting that these windbreak forests might be used by bats as migration pathways

View full abstract

Surveys of bats were performed in the Inada and Kawanishi areas, located in the margins between the urban region and the agricultural region of Obihiro City, Hokkaido in the summer seasons of 2000, 2001 and 2005. Using mist nets, three bat species, Myotis frater, Nyctalus aviator, and Plecotus auritus were caught. They were lactating or post-lactating females or juveniles born in the year when the animals were caught, demonstrating that these species had bred within the areas investigated. Myotis frater and Nyctalus aviator are believed to breed in hollows in trees such as Quercus dentata. On the other hand, Plecotus auritus appeared to have a breeding colony in a wooden Shinto shrine. Myotis frater fed around forest streams.

View full abstract

The alien red-bellied tree squirrel, Callosciurus erythraeus (common name : Formosan squirrel), is common in woodlands of Yokohama Nature Sanctuary, Kanagawa Prefecture, Japan. By the route censuses conducted in the early morning, 1.2 individuals were observed per hour regardless of vegetation types. The number of observed squirrels was lower in winter than the other seasons. Especially, the squirrels were not active in the morning less than 0℃ in temperature. From December to March, the number of squirrels acting outside the nest increased with rising temperature in the morning. Therefore, the low temperature in winter may be one possible factor restricting further expansion of this alien species in Japan.

View full abstract

In Mt. Tokachi, volcanic mountain, the field signs of the pika are only found in the lava pile area, but not in the area where lava rocks are almost buried in sand, and Sasa plant has already invaded, becoming to a forest. Space holes between lava rocks play an important role for them to nest, stack fodder. Their food plants are sub-alpine shrubs, grasses and mosses in their territories.

View full abstract

With the reference to Nopporo field example in the previous report (Higuchi and Hayashi, 2005), it is possible to simulate a population of more than 100/ha through Leslie matrix with high birth rate, for instant 3.0, and the same survival rate as in Nopporo example in each cohort. In this connection, birth rate is : 'average number of embryo' (5.0)×'ratio of female to male' (0.5)×'time of pregnancy per month' (1.0〜1.5)=2.25〜3.75, moreover with 'pregnancy rate per female' (0.0〜1.0), adjusting to actual birth number. Monthly age class structure is a vector which is projected through Leslie Matrix with pertinent growth rate and survival rate from the former month vector, and is useful for the index of population growth in the red-backed vole.

View full abstract

An adult population of a papilionid butterfly, Luehdorfia japonica Leech was studied by marking, release and recapture procedures in a hilly region of Matsunoyama Town, Niigata Prefecture. Thirty-two males and 15 females were marked and released, and 13 males and one female were recaptured at least once. Daily survival rate estimated by Jolly-Seber method was 0.75, and that estimated by recapture duration decay plotting was 0.81, respectively. Estimated total population size per generation was 39.7 by Jolly-Seber method, but this could be an underestimation. The total population size derived from a new method developed from recapture duration decay plotting was 68.4.In comparison with a high density population of the same species studied earlier, the low density population studied here was different in that the butterflies were mostly found solitary and patchy structure of the population was unclear, and although the males mostly flew around in search for females, sometimes they exhibited hilltopping with perching behaviour on some summits or patrolling behaviour on summits and ridges.

View full abstract