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Breeding records of the Eastern Marsh Harrier, circus aeruginosus opilonotus in the Hachirogata reclimed land, Akita Prefecture

1979; Volume: 11; Issue: 2 Linguagem: Inglês

10.3312/jyio1952.11.2_109

1883-3659

Takashi Nishide,

Avian ecology and behavior

The breeding study of the Eastern Harsh Harrier Circus aeruginosus spilontus had been carried out in the special refuge of the Ogata-grassland of the Hachirogata reclimed land for three years (from 1976 to 1978).I found one nest in each year, and there was only one nest (in 1978) a chick grew up. The nests built were fairly rough. Dead reeds and grasses were piled up disorderly on a base of the nest.Eggs were laid every 3.3 days on an average, and the number of eggs was 7 in 1976, 5 in 1977, and 6 in 1978 repectively.One of 6 eggs hatched out on the nest in 1978. The growing of a chick showed a tendency to be slow in the early stage, and quick in the late stage. After the hatching out, the chick stood up with its elbows by about 17th day, and came to stand up with its legs streched out py about 25th day.About 27th days later, the chick left the nest, and moved on the grassland from place to place. A month later, the plumage of the chick changed to be dark brown (over its head, back, wings and tail), and looked like a bird of prey. About 35 days later, it began to practice beating its wings.It is very interesting that the male carried and passed foods to the female in the air. It took about seven minutes to do it.I observed the interesting habit that the chick had the six times movement that the chick pushed down the grass, and paved there dead grasses to build imitating nests everytime he moved.The male took foods at the place about 5km away from the nest, and its behaviour of the defence for the territory was observed about 150-200m away from the nest.