White-rumped Sirystes

The white-rumped sirystes is 18 to 19 cm (7.1 to 7.5 in) long and weighs 24 to 32 g (0.85 to 1.1 oz). The sexes have the same plumage. Adults have a black crown with a slight crest. The rest of their face is slate gray. Their nape and back are mottled gray with a large white rump patch. Their wings are blackish with pale gray edges on the coverts and white edges on the inner flight feathers. Their tail is long, blackish, and has a square tip. Their throat and breast are pale gray that becomes white on the belly. They have a coffee-brown iris, a black bill, and blackish legs and feet. Voice: One song of the white-rumped sirystes's is "a mellow series of whistles, e.g. p'weer PEW-pu". Another is a chattering "wheer-pi'pi'pi'pi'pi'pi'". Its calls include a "variable series of pew notes", "quieter kew or pew" notes, and "a whistle, followed immediately by a short note wher-péw".