Surniculus lugubris ( ) is a small bird of the family Rhododendron , genus Slubbon , with a body length of 23–28 cm , black throughout , a shallow forked tail , and a white transverse spot on the undertail coverts and lateral tail feathers , which are conspicuous at the black tail. The underparts are black with slightly blue or glow green. The iris is brown or crimson, the mouth is black, and the feet are grayish blue.
China is found in Tibet, Metuo, Sichuan, Yunnan, Guizhou, Guangxi, Fujian, Guangdong, Hong Kong and Hainan Island.
It is active in single or pairs, often singing among the top branches of the middle and upper layers of trees, and sometimes in bamboo forests, mainly perched and active in trees. Fly silently, in undulating waves, and in a fast straight line when pressed. The posture is more vertical when standing. The sound is 6 syllables, like a whistle, and the scale gradually increases. Sometimes a two-syllable sound of "wee onewhip" is also emitted.
The breeding period of the black cuckoo is from March to May, and it does not nest to incubate eggs, usually laying eggs in the nests of birds such as capuchin, swallowtail, mountain pepper bird, white-throated red-rumped grebe, swamp big-tail warbler, etc., and other birds incubate eggs and brood for it. The eggs are short oval in shape, yellowish with reddish spots scattered on them.