Crocodile bulks of swallowed prey flesh and bone. Many large crocodilians swallow stones (called gastroliths or stomach stones), which may act as ballast to balance their bodies or assist in crushing food, similar to grit ingested by birds. Herodotus claimed that Nile crocodiles had a symbiotic relationship with certain birds, such as the Egyptian plover, which enter the crocodile's mouth and pick leeches feeding on the crocodile's blood; with no evidence of this interaction actually occurring in any crocodile species, it is most likely mythical or allegorical fiction. Since they feed by grabbing and holding onto their prey, they have evolved
Grey plover crustaceans, and insects. It is less gregarious than the other "Pluvialis" species, not forming dense feeding flocks, instead feeding widely dispersed over beaches, with birds well spaced apart. They will however form dense flocks on high tide roosts. The grey plover is one of the species to which the "Agreement on the Conservation of African-Eurasian Migratory Waterbirds" (AEWA) applies. Grey plover The grey plover ("Pluvialis squatarola"), known as the black-bellied plover in North America, is a medium-sized plover breeding in Arctic regions. It is a long-distance migrant, with a nearly worldwide coastal distribution when not breeding. The genus name is