環境

Breeding status of the Peregrine Falcon Falco peregrinus was investigated in mountainous area in Tama River and Akikawa River Basin in Tokyo From April 2017 to March 2018.

In 2017, We checked 14 cliffs as possible nesting sites of the area and found the nests at 8 sites. We observed breeding behaviour such as incubation and feeding the young by the parents at these nests. Some indirect signs of the falcon breeding were observed at two sites: courtship display and visiting to the cliff, respectively. Of the total nest sites, eight were natural cliffs and two were artificial ones. Most of the nesting cliffs faced southward. The average number of fledglings were 3.29 ± 0.76 (x ± SD, range=2-4, N=7).

In the early spring of 2018, We checked 8 nesting cliffs. We observed visit the cliff or incubation by the parents at 7 out of 8 nesting cliffs.

Takashi Yamaguchi