This weekend I cannot go birding and this pics were taken last week. Japan Ornithological Congress was held in Hyougo-pref west of Japan last week and I spend good time. I wanna say thank you to the people I talked with. The term of this article is struggle of Bull-headed Shrikes. Bull-headed is one of the popular bird in Japan. 23 Sep, I was birding in Chiba-pref and I found three Bull-headed's territories and I watched the struggle of 1w-female & 1w-male at that time. Both individual's territory call were very loud, and many time 1w-male fly over the territory of 1w-female. After that, 1w-female attacked 1w-male. In detail, 1w-male put territory call on bush and 1w-female dived to the bush. About 2.5 minute, they were in the bush. I observed with scope, but couln't see much what they did. So I decided to take photos and confirm with pic.
Female bite the neck of male. Female bite male over 1minutes! In this situation, they didn't put any calls. I think it is hard to fight back on male. I judged the female's age from the color of PC and male's age from edge of covers. It is very chaotic pic but we can see the eyes of both individuals.
The situation was changed and female bite male's leg. Observation after this struggle, I find that male cared his leg. So that time I thought he was injured in the struggle, and it is maybe true. Injude is affect avian mortality and survival rate. If the bird lost only one finger, it will influence in the removal of Louses. Louses live on bird's feathers and the relationship is so strong. One of the species of Louses are living in the throat of Pelicans!! From this pic, male maybe fight backed and bite female's leg. After this fight back from male, female flew away with the call "gya- gya-". This was the settlement of this struggle. Anyway, this is some rare case in the struggle of Bull-headed. Almost struggles are only chase. Body contact has a lot of risk, so many avian species avoid to do. Red-flanked bluetail also avoid body contact and maybe many Japanese birders can image easy.
The territory call of male from the new territory like Roar of victory with wing shaking. Shaking is used for threat, however it is used for courtship feeding. Shaking wings of female in courtship feeding reminiscent me the chicks. It is so cute. The possibility not be denied that the meaning of the behavior of threat changes in breeding season. But I think, hypothesis of "reminiscent me the chicks" is more adaptive. Because If I was a Bull-headed, I would choose cute girl rather than frightening girl. Maybe I will post the article about Kamchatka Leaf Warbler next time.