Yesterday, I went to south-Boso south of Chiba pref. When I walk there, I sliped down from slope and broke parts of degiscoping materials. After that, I walk around river and wallowed. My tripod disappeared that time..., really sad. Mountainous region that 2-300m high of Boso, the clay land are easy to slip. So be careful. Anyway, the subject of this article is Japanese wood pigeon.
カラスバト♂ (Columba janthina) male Japanese wood pigeon 150509 Yamagata
Scraching. I determined to male from copulation. I think Eastern turtle dove flirting many times, but this Japanese wood pigeon pair did't flirting. They did little mutual preeing but not long. I don't know the system of breeding. I think they make shared roost. Their distribution of Japan is unique, they inhabits in island and rare in main land.
カラスバト番い (Columba janthina) R:female F:male Japanese wood pigeon 150509 Yamagata
Japanese wood pigeon don't like aggression. But it is difficult to see the situation they are calm. We usually see they are flying. The body size different between male and female of Dove and Pigeon is vary by species. I don't know the trend of pigeon body size so please tell me if you knows. Anyway, There are the trend for isolate population of wild life that the body size will be large, because of the little number of predator, the large body makes easy to maintain body temperature high in without heavy predation risk and can have the long intestine. On the other hand, Japanese wood's size is not vary in spite of they inhabits in a lot of islands. From this, they were inhabited in main land a little ago. The little number of subspecies is support this idea. It is difficult to answer the reason why they disappeared from main land. I have a two idea, first one is the high predation risk of main land and second is they were lose the competition to other pigeon like Eastern turtle dove. By the way, why Eastern turtle dove don't succeed in little island? Many Japanese little island has little population of Eastern turtle despite of the large number of main land. The breeding system that male do display together in one place is the origin?? I really want to know the reason why.