Potential host species of the Cuckoo in Japan, frequency of parasitism in central Honshu, and the process of the establishiment of a new parasitic relation with the Azure-winged Magpie Cyanopica cyana were studied both by literature and field work.
1) Twenty-eight species have been recorded as cuckoo hosts in Japan and twelve species of them are major hosts. The numbers of host species were greatest in central Honshu (20 species).
2) The mean rates of parasitism by the cuckoo on a total of six major hosts were more than 10 in Nagano Prefecture, central Honshu. The highest parasitism rate was 79.6% on a local popula-tion of the Azure-winged Magpie.
3) Dynamic changes of parasitic relations between cuckoos and the hosts occurred during the last 60 years. About 15 years ago, the Cuckoo began to parasitize the Azure-winged Magpie. The parasitism rate increased rapidly and has now expanded to almost all of the breeding range of the Magpie. Conversely, the Siberian Meadow Bunting Emberiza cioides has become a rare host.
4) The new parasitic relation with the magpie started as the result of their range overlap after their range expansions. In most regions, the cuckoo parasitism on the magpie did not start soon after their range overlap, but took about 10 to 15 years.
5) The characteristics of the cuckoo parasitism in Nagano Prefecture and the process of the establishment of new parasitic relation were discussed.

View full abstract

1) Linear discriminant analysis was performed on external morphological measurements to distinguish yearling from older (≥2-year-old) Alpine Accentors Prunella collaris.
2) From 17 May to 15 June in 1985-1989, morphological variations in eight characters were measured in 148 known-age individuals inhabiting the top of Mt. Norikura, central Honshu, Japan.
3) In both sexes, older birds were significantly heavier and had longer wings and tails than did yearlings, but tarsus length, three bill dimensions and head length showed no increase with age.
4) Stepwise discriminant analysis was performed on body weight (BW), wing length (WL), and tail length (TL). The resultant final functions were as follows:
Male: Z=0.592WL+1.008TL-131.330
Female: Z=0.411BW+0.504WL+0.353TL-87.300
Age classes were assigned based on the discriminant scores (Z), as yearlings when Z < 0, and as olders when Z>0.
5) This analysis proved to be a useful aging method in its reliability and objectivity. By the discriminant function, males and females could be aged in 96.4% (80/83) and 86.2% (56/65), respectively. The classification success rate was much higher than that calculated by the discriminant analysis using a single variable.

View full abstract

The diet consumption of Tetrastes bonasia chicks was investigated in captivity in 1987 and 1988. Chicks were supplied with an artificial diet composed of 9.5 to 21.0% crud protein, 2.1 to 17.2% crude fat and 1.5 to 4.8% crude fiber. The gross energy of the diet ranged from 2, 033.9 to 3, 880.6 kcal/kg in different ages. Diet consumption in dry weight was 1.5 g/day/bird in 2 days old chicks, increasing to 24.8 g/day/bird in 46 days old chicks and averaging 22.1 g/day/bired after 50 days old chicks. The body weight just after hatching averaged 11.4 g and reached 300 g or more in 98 days old chicks. Forty-nine days old chicks atained 69% of adult weight, 82% of adult wing length, 95% of adult bill lenght, and 98% of adult tarsus length. The relationship between the age in days (X) and diet consumption per body weight (Y) is Y=-0.0941+15.34. The survival rate was 90% in 35 days 65% in 112 days old chicks. The main cause of death after 42 days old was aspergillosis and peritonitis. A standard diet was presented based on the data for diet consumption.

View full abstract

One male and two young of the House Sparrow Passer domesticus were found on Rishirt Island, northern Hokkaido, on August 4-7, 1990. This is the first record of the species in Japan.

View full abstract

The Japanese Lesser Sparrowhawk Accipiter gularis breeds in mountain forests of Hokkaido, Honshu, Shikoku and Kyushu in Japan. However, its breeding has been observed in recent years in some small forest patches close to residential areas. We observed nine active nests at eight places in Tochigi Prefecture, central Honshu, in 1989. The breeding habitat was a mixture of residental area and agricultural field with patchy forests, or a residental area with small forest patches. A pair nested on a solitary tree near the main exit of an elementry school, where many cars and people went through. Some pairs bred in small patchy forests 7.5-22m away from human habitation. The presense of nesting trees, occurrence of small birds as available food, and the tameness of this species may be the reason why they breed in small patchy forests of residental areas.

View full abstract