Abstract
A nest of the Short-tailed Bush Warbler Cettia squameiceps was found in the Japanese Cypress Chamaecyparis obtusa forest, at Owachi (E 137°57′, N 53°28′, altitude 700 m) in Shimoina-gun, Nagano Prefecture, on 29 April, 1981. On 30 May, one of the authors noticed 3 adult birds attending the nest simultaneously. In order to compare differences in nestling-care behavior of these 3 birds, a continual nest-watch was carried out for a total of 228 min. on 31 May. Two birds are considered to be the parents and the other a helper. This is the first observation of helping at a nest of the Short-tailed Bush Warbler in Japan.
