The tropical sun burns off the Nile's shallow waters, leaving a shifting mosaic of pools and new grassland. Now it's time for the Dinka to return. But others fare less well as the land re-emerges. This catfish could easily find itself stranded, but it has a curious ability that might just save it. If it can't swim, it'll crawl. Specially adapted fins allow the catfish to walk on its elbows. Like the lungfish, it can also breathe air. It may have to perform this trick many times as its habitable world gets smaller by the day. Meanwhile, the kob are on the move again. Their world is expanding rapidly. As the floodwaters recede, a huge green carpet of new grass rolls out before them. This explains how the Sudd can support such massive herds.


热带的烈日烤干了尼罗河的浅滩， 留下由零星水塘和新生草地组成的形态变换不定的马赛克图案。丁卡族踏上归途的时刻到了。但大地再现却也对某些生物产生了不利影响。这条鲶鱼很有可能会因此而搁浅，但它拥有自力救济的特异功能。如果不能游水，那么就用爬的。特殊造型的鱼鳍让鲶鱼可在陆地上靠肘部爬行，它和肺鱼一样可以呼吸空气。在它的栖地日渐缩小时，一天之中它可能得演出好几次这样的绝技。同一时刻，赤羚们也展开了行动。它们的世界迅速扩大。随着大洪水退去，宽广的大片新生绿地就在它们的面前铺展开来。难怪苏德沼泽能够供养为数如此众多的生物群。