Black-tailed myiobius

Seven subspecies are recognised; M. a. atricaudus from southwestern Costa Rica, Panama and western Colombia; M. a. portovelae from western Ecuador and northwestern Peru; M. a. modestus from eastern Venezuela; M. a. adjacens from southern Colombia, eastern Ecuador, eastern Peru and western Brazil; M. a. connectens from northeastern Brazil south of the River Amazon; M. a. snethlagei from northeastern and eastern Brazil; M. a. ridgwayi from southeastern Brazil.[2]

The black-tailed myiobius closely resembles the whiskered myiobius (M. barbatus) and the sulphur-rumped myiobius (M. sulphureipygius) in appearance, with olive upper parts and a yellow rump. The underparts differ in being buff rather than tawny or greyish-olive, but birds living in eastern Brazil tend to have yellowish or yellowish-buff underparts. Another distinguishing feature is the location in which the bird is seen. The black-tailed myobius haunts woodland edges and secondary forests and is less active or acrobatic than the other two species; it is found at altitudes up to 1,400 m (4,600 ft).[4]

The species has a patchy distribution in tropical Central and South America. It is present in Costa Rica, Panama, Colombia, Venezuela, Ecuador, Peru (on both sides of the Andes) and large parts of Brazil.[1] Where their ranges overlap, it is generally found in drier habitats than the whiskered myiobius (M. barbatus), and at higher elevations.[5] It generally frequents forest verges and secondary growth, often near water, whereas the whiskered myiobius prefers the interior of forests.[4]

Destruction of the Amazon rainforest is reducing the area of suitable habitat for this bird and its numbers are thought to be in decline. It is an uncommon species with a patchy distribution, nevertheless, it has a very wide range and the total population size is likely to be large; as a result, the International Union for Conservation of Nature has classified it as being of "least concern.[1]