Male crocodiles of the Nile river could face extinction due to an invasive plant. The trifid weed has invaded the shoreline-nesting habitat for the crocodiles at Greater St Lucia Wetland Park, the largest estuarine system in Africa. The fibrous roots of the weed cause some nesting crocodiles to abandon their nest sites, while shade from the plant alters the temperature of other nests, resulting in all female hatchlings.

"This problem is definitely not limited to St Lucia,' said Alison Leslie, chairperson of the Herpetological Association of Africa. "If ignored it will significantly affect crocodile populations in South Africa,' he added. As in several reptiles, the temperature of the nest determines the sex of crocodiles.