The White-crested Tyrannulet (Serpophaga subcristata) is a small species of bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 in the Tyrannidae family. It is found in woodland and open habitats with scatted bushes and trees in Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

, Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, Paraguay

Paraguay

Paraguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...

, and Uruguay

Uruguay

Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

. It is closely related to the White-bellied Tyrannulet

White-bellied Tyrannulet

The White-bellied Tyrannulet is a small species of bird in the Tyrannidae family. It is found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay. It is found in open forest, woodland and various open habitats with scattered trees. It is closely related to the White-crested Tyrannulet, but that...

, but unlike that species the belly of the White-crested Tyrannulet is yellow. The recently described Grey-crowned Tyrannulet

Grey-crowned Tyrannulet

The Grey-crowned Tyrannulet , also known as the Monte Tyrannulet and Straneck's Tyrannulet, is a small species of bird in the Tyrannidae family. It is found in woodland and open habitats with scatted bushes and trees in south-central South America, but the details are still unclear. It breeds in...

is extremely similar to the White-crested Tyrannulet and was for a long time confused with that species; the two are generally best separated by voice.