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. They are not closely related to Old World warblers or Australian warblers. Most ...

that is resident from

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south to northwestern

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and disjunctly in the western

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

. 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 in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

, Peru and

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

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 biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

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

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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 Valley ( es, Valle del Río Magdalena) is a valley in Colombia located within the Colombian Andes. The valley is specifically situated between the Central and Eastern Ranges and crossed by the river of the same name, the Magdale ...

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

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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

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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 pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

s and other small

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

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 Alaska ...

, 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