Maybe each male is trying to show how strong and dexterous he is 这或许是雄江豚展示自己 强壮身体和敏捷身手的一种方式
Each year nearly two million animals migrate across the Serengeti plains 每年都会有将近200万只角马 横越塞伦盖蒂平原
But each year over 50,000 demoiselle cranes set out on one of the most challenging migrations on Earth. 可是 5万多只蓑羽鹤每年都会 进行一场地球上最具挑战性的迁徙
You might expect that grazers would avoid each other's patch 你或许会认为食草动物 总是尽量互相避让