The Charadriinae (scientific name) or plover is a sub-family of 66 different species of wading birds that have a cosmopolitan distribution, excepting in the Sahara and polar regions. They are medium-sized birds, which have plumage colouration of black, white, rufous, grey and brown. Their height can vary depending on the species and the length of their legs. However, they all have short beaks. Their diet is comprised of insects, worms and invertebrates which it hunts for with sight rather than like its distant cousins which they do by feeling. The average clutch-size varies from 2-6 eggs and incubation period varies from 27 days to a month depending on the species. The IUCN listing varies depending on the species, from the LEAST CONCERN to NEAR THREATENED.