This male Grey Heron shows two type of courtship displays. One is called Stretch, in which he lifts his head and bill towards the vertical. Another is called Stretch-Snap, in which he moves his head fowards and downwards, and snaps his mandibles shut.
求愛ディスプレイ中の雄のアオサギです。頭を垂直に上に伸ばすディスプレイと、頭を前方ないし下方に突き出しくちばしを鳴らすディスプレイの2タイプが見られます。耳をすませば、くちばしを鳴らすときのカポンという乾いた音も聞こえます。
『アオサギを議論するページ』www.grey-heron.net/
4 апр 2011
