Abstract
The nesting ecology of a marked population of the Fan-tailed Warbler Cisticola juncidis was investigated for five years, 1978-1982, in the Shinoda-yama grassland in Japan.
(1) Males constructed their first nests almost synchronously one month after their arrival.Nest building activity occurred throughout the day and continued until the end of August.
(2) Almost all the males re-used some materials from abandoned nests; seemingly due to a shortage of cobwebs.
(3) Nests were supported by living grasses, mainly a kind of pampas grass (41.9%), alang grass (34.0%), and eulalia (11.3%).
(4) Nests were on average about 20 cm above the ground, and the height gradually in-creased as the season went on.
(5) Nest entrances faced mainly to the east due to westerly winds in the area.
(6) The activity patterns and the characteristics of courtship nests mostly agreed with those of two other local populations in Japan
