【BBC地球脉动】淡水 13

英语自学网

In these murky waters they rely on sonar to navigate and hunt. They work together to drive shoals of fish into the shallows. Botos are highly social and in the breeding season there is stiff competition for mates. The males hold court in a unique way. They pick up rocks in their jaws and flaunt them to their attending females. Maybe each male is trying to show how strong and dexterous he is and that he therefore is the best father a female could have for her young. Successful displays lead to mating. Even for giant rivers like the Amazon the journey to the sea  is not always smooth or uninterrupted.在这条混浊的河流里，它依赖声纳来导航和捕食。它们集体行动，把鱼群驱赶到浅水里。亚马逊海豚是高度社会化的动物，在交配季节，它们会为争夺配偶而激烈竞争。雄海豚会用一种独特的方式求偶。它们会把石头含在嘴里向自己中意的雌海豚炫耀。雄海豚可能是借此来显示自己的力量和灵活性，表明它自己是未来宝宝最出色的父亲。成功的表演导致了交配。即使像亚马逊河这样的大河，它流往大海的道路也不总是畅通无阻的。