The neotropic cormorant or olivaceous cormorant (Nannopterum brasilianum) is a medium-sized cormorant found throughout the American tropics and subtropics, from the middle Rio Grande and the Gulf and Californian coasts of the United States south through Mexico and Central America to southern South America, where it is called by the indigenous name of biguá. It also breeds on the Bahamas, Cuba and Trinidad. It can be found both at coasts (including some mangrove areas) and on inland waters. There are at least two subspecies: N. b. mexicanum from Nicaragua northwards and N. b. brasilianum further south. In Peru the neotropic cormorant is used by the Uru people for fishing. Taxonomy The neotropic cormorant was documented in 1658 by the Dutch naturalist Willem Piso after travels in Brazil. This formed the basis for the formal description and naming of the species by Johann Friedrich Gmelin in 1789. He placed it with the petrels in the genus Procellaria and coined the binomial name Procellaria brasiliana. Many authors preferred to use Alexander von Humboldt's 1805 description of Pelecanus olivaceus because the identity of Piso's birds was considered uncertain. Later, ornithological authorities such as the American Ornithologists' Union began to use Phalacrocorax brasilianus after Ralph Browning argued that Piso's description and paintings do indeed refer to the neotropic cormorant. The neotropic cormorant was formerly placed in the genus Phalacrocorax. A molecular phylogenetic study of the cormorants published in 2014 found that the neotropic cormorant, the double-crested cormorant and the flightless cormorant formed a clade that was sister to the genus Leucocarbo. The three species were therefore moved the resurrected genus Nannopterum that had been introduced in 1899 by English ornithologist Richard Bowdler Sharpe to accommodate the flightless cormorant. The genus name Nannopterum combines the Ancient Greek nannos meaning "dwarf" with pteron meaning "wing". Two subspecies are recognised: N. b. mexicanum (Brandt, JF, 1837) – inland and coastal Great Plains (central USA) from South Dakota and Kansas to Gulf of Mexico, and Mexico to Nicaragua; Bahamas and Cuba N. b. brasilianum (Gmelin, JF, 1789) – inland and coastal Costa Rica to Tierra del Fuego Description This bird is long with a wingspan. Adults males weigh from , adult females less. Birds of the southern populations tend to be bigger than the more northerly birds. It is small and slender, especially compared to the larger, heavier-looking double-crested cormorant. It has a long tail and frequently holds