Brazil has one of the richest bird diversities in the world. The avifauna of Brazil include a total of 1858 confirmed species of which 238 are endemic. Five have been introduced by humans, 96 are rare or vagrants, and five are extinct or extirpated. An additional 14 species are hypothetical (see below). Brazil hosts about 60% of the bird species recorded for all of South America. These numbers are still increasing almost every year, due to new occurrences, new species being described, or splits of existing species. About 10% of the bird species found in Brazil are, nonetheless, threatened. In June 2013 a simultaneous discovery of fifteen bird species in Brazil was announced, the first such since 1871, when August von Pelzeln described forty new species. The birds were from the families Corvidae, Thamnophilidae, Dendrocolaptidae, Tyrannidae, and Polioptilidae. Eleven of the new species are endemics of Brazil and four also inhabit Peru and Bolivia. Except as an entry is cited otherwise, the list of species is that of the South American Classification Committee (SACC) of the American Ornithological Society. The list's taxonomic treatment (designation and sequence of orders, families, and species) and nomenclature (common and scientific names) are also those of the SACC. Two additional species are added from other sources and are not included in the above counts. The notes of population status, for instance (endangered), are those of the International Union for Conservation of Nature (IUCN) Red List. The status notes apply to the worldwide population, not solely the Brazilian population except for endemic species. The following tags have been used to highlight several categories of occurrence. (V) Vagrant - a species that rarely or accidentally occurs in Brazil (E) Endemic - a species endemic to Brazil (I) Introduced - a species introduced to Brazil as a consequence, direct or indirect, of human actions (H) Hypothetical - a species recorded but with "no tangible evidence" according to the SACC Rheas Order: RheiformesFamily: Rheidae The rheas are large flightless birds native to South America. Their feet have three toes rather than four which allows them to run faster. Greater rhea, Rhea americana (near-threatened) Tinamous Order: TinamiformesFamily: Tinamidae The tinamous are one of the most ancient groups of bird. Although they look similar to other ground-dwelling birds like quail and grouse, they have no close relatives and are classified as a single family, Tinamidae, within their own order, the Tinamiformes.