Oriental Turtle Dove Calling on the Perch at Daybreak

An Oriental turtle dove (aka Eastern turtle dove or rufous turtle dove; Streptopelia orientalis, family Columbidae) perched on a leafless shrub of round-leafed Siebold's viburnum (Viburnum sieboldii var. obovatifolium, family Adoxaceae) at the deserted sett of Japanese badger (Meles anakuma, family Mustelidae). The bird called in a low tone “guoo” before and after take-off from the perch. I’d never heard such a strange call by an Oriental turtle dove. It was likely to be an alarm call, but against what? Captured with my new trailcam early in the cloudy morning (around 6:20 AM) of mid-November 2024 in Japan. It was 9 degrees Celsius. The sunrise time was 6:14 AM. For a full story (text in Japanese); https://sigma-nature-vlog.blogspot.com/2026/02/blog-post_04.html