Серо-чёрный колючник Thamnophilus nigrocinereus

A fairly large antshrike of riparian zones with lots of regional variation in plumage. Males are dark gray above, paler below, with white wing bars (not spots); the northwest subspecies is gray with a black cap. Females are rusty with a dark-gray hood. Found in seasonally flooded forests, river island forests, and mangroves. Forages close to the ground and sometimes accompanies mixed-species flocks. The song is an accelerating series of whistled descending notes.