Leaden Antwren Myrmotherula assimilis

The Leaden Antwren is a small slaty-gray member of the genus Myrmotherula that is mainly restricted to the understory of older, established river-islands along the Amazon River and its larger tributaries, from northeastern Peru east to central Brazil. This is the only species of gray antwren found on Amazonian river-islands. Males are entirely light slaty-gray with white tips to the wing coverts, forming two distinct wingbars. Females are light buff below, gray above, and also have two faint white wingbars. Both sexes have a concealed white interscapular patch that is flashed when the bird is agitated. Leaden Antwrens are found in isolated pairs in the understory of taller, seasonally flooded forest, particularly where there are dense stands of Heleconia. It is most similar to the Gray Antwren (Myrmotherula menetriesii), but that species is associated with mixed-species flocks in terra firme and transitional forest, and is unlikely to co-occur with Leaden. Songs are also very different between these two species. The primary song of Leaden has a rapid descending trill “te-te-te-tu-tututututrrrrr,” speeding up into almost a dry rattle at the end. The song of Gray Antwren is a series of high-pitched clear whistles, a “seeee-seeee-seeee-seeee-seeee.”