No person lives in that house since an old woman died out several years ago, so that the garden has been out of order. This region has approximately a 80 x 80 m area, surrounded by fences, where we cannot enter without owner's permission. The garden is occupied by a large number of tall trees, and is therefore utilized for a relaxation area of many birds. A pond dug out is at the corner of the garden, in which the toad Bufo japonicus formosus has long bred. I had heard of the present call far away from this pond.

On 3 July, I had an opportunity to go around several breeding ponds of Z. arboreus, and thus verified this call was the same as that of this species. The vocalization appeared to originate from only an individual male, and lasted for a couple of months. I am interested in where this male came from. I wonder whether anyone released it in the garden or any bird brought it in; its problem is now left unsettled.