The southern beardless tyrannulet (Camptostoma obsoletum) is a small passerine bird in subfamily Elaeniinae of family Tyrannidae, the tyrant flycatchers. It is found in Costa Rica, Panama, in every mainland South American country except Chile, and on Trinidad.
Taxonomy and systematics
The southern beardless tyrannulet has these 13 subspecies:
C. o. flaviventre Sclater, PL & Salvin, 1865
C. o. orphnum Wetmore, 1957
C. o. majus Griscom, 1932
C. o. caucae Chapman, 1914
C. o. pusillum (Cabanis & Heine, 1860)
C. o. napaeum (Ridgway, 1888)
C. o. maranonicum Carriker, 1933
C. o. olivaceum (Berlepsch, 1889)
C. o. sclateri (Berlepsch & Taczanowski, 1884)
C. o. griseum Carriker, 1933
C. o. bolivianum Zimmer, JT, 1941
C. o. cinerascens (Wied-Neuwied, M, 1831)
C. o. obsoletum (Temminck, 1824)
Several authors have suggested that the southern beardless tyrannulet may be composed of more than one species. Genetic evidence suggests that as many as three may be present. The Clements taxonomy divides the subspecies into two groups within the species. The northern (pusillum) group includes the seven subspecies C. o. flaviventre through C. o. olivaceum in the above list and the southern (obsoletum) group includes the other six.
The southern beardless tyrannulet shares genus Camptostoma with the northern beardless tyrannulet (C. imberbe); they have at times been considered conspecific and together they form a superspecies.
Country Inn - Panama City, Panama
Description
The southern beardless tyrannulet is 9.5 to 10.5 cm (3.7 to 4.1 in) long and weighs 7 to 9 g (0.25 to 0.32 oz). It is a small flycatcher with a long pointed warbler-like bill. The sexes have the same plumage. Adults of the nominate subspecies C. o. obsoletum have a grayish crown and nape; the crown feathers are often bushy with dark centers. They have white lores and a broken white eyering on an otherwise grayish white face. Their upperparts and tail are medium olive-gray. Their wings are dusky with...
