The buff-rumped warbler (''Myiothlypis fulvicauda'') is a

New World warbler The New World warblers or wood-warblers are a group of small, often colorful, passerine birds that make up the family Parulidae and are restricted to the New World. The family contains 120 species. They are not closely related to Old World warb ...

that is resident from

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, ...

south to northwestern

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

and disjunctly in the western

Amazon Amazon most often refers to: * Amazon River, in South America * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon (company), an American multinational technology company * Amazons, a tribe of female warriors in Greek myth ...

. It is found in forests at up to 1500 m altitude, always near water. The pair builds a bulky domed nest with a side entrance on a sloping bank next to a stream or path, and the female lays two white eggs which are incubated for 16–17 days with another 13–14 days to fledging. The buff-rumped warbler is 13–13.5 cm long and weighs 14.5 g. The nominate race ''M. f. fulvicauda'' of western Amazonia in

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

, Peru and

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

is dark olive-brown above with a grey head, buff supercilium, and the conspicuous rich buff rump and upper tail that give this species its English and scientific names. The lower half of the tail is blackish. The underparts are whitish with some buff on the flanks. The sexes are similar, but the young bird is browner on the upperparts, head and breast, and its rump is paler. There are five other

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

. * ''M. f. semicervina'', is found in the Chocó from eastern

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

to north-western Peru. It is similar to ''fulvicauda'', but the buff area of the tail is larger and paler, and the buff on the flanks is more extensive. * ''M. f. motacilla'', from the

Magdalena Valley The Magdalena River (, ; less commonly ) is the main river of Colombia, flowing northward about through the western half of the country. It takes its name from the biblical figure Mary Magdalene. It is navigable through much of its lower reaches, ...

in Colombia, is similar to ''semicervina'', but the buff area of the tail is paler, and upperparts more olive. * ''M. f. leucopygia'', from the Caribbean slope in

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

is a distinctive form, with a much paler buff rump, a white supercilium, dark legs, and dark spotting on the breast. * ''M. f. veraguensis'', from the Pacific slope in Central America is like ''leucopygia'', but less spotted and with a somewhat darker rump. * ''M. f. significans'' of south-eastern Peru and northern

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

has a less extensive buff rump than other subspecies, and olive upperparts. This is a common species, easily seen and identified as it hops on the ground, pumping and swinging its broad tail constantly. The buff-rumped warbler primarily feeds on

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

s and other small

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s, taken on the ground or in flight in open areas along the banks of streams, puddles, roadsides or tracks. Pairs defend their linear feeding territories along a stretch of stream throughout the year. The call note of the buff-rumped warbler is a hard ''tschik'' like

northern waterthrush The northern waterthrush (''Parkesia noveboracensis'') is a species of ground-feeding migratory New World warbler of the genus ''Parkesia''. It breeds in the northern part of North America in Canada and the northern United States including Alask ...

, and the male's song is a warble followed by a series of 8–15 ringing ''chew'' notes. The female may give a soft reply.

References

* Curson, Quinn and Beadle, ''New World Warblers'' * Stiles and Skutch, ''A guide to the birds of Costa Rica''

References

Further reading