White-crested Tyrannulet (Serpophaga subcristata) [XC582215]
by Ciro Albano from Rio Jo\u00e3o Mendes, Niter\u00f3i, Rio de Janeiro, Brazil (call)
White-crested Tyrannulet (Serpophaga subcristata) [XC773706]
by Aluisio Ribeiro from Po\u00e7\u00f5es, State of Bahia, Brazil (song)
Subspecies
Taxonomic status controversial. Sometimes considered conspecific with White-bellied Tyrannulet (Serpophaga munda), but the two differ in plumage, also slightly in voice, and in Argentina are narrowly parapatric with limited hybridization. Further study is required.
The following 2 subspecies are recognised:
subcristata (Vieillot, 1817) - Bolivia (from northern La Paz) and southern Brazil (southern from southern Mato Grosso) south through Paraguay to Argentina (south to northern Chubut).
straminea (Temminck, 1822) - South-eastern Brazil (southern Piauí and Bahia south to Rio Grande do Sul) and Uruguay.