Sumatran Ground-Cuckoo

The Sumatran ground cuckoo is a large bird of about 55 cm (22 in) in length. Its wings and long, full tail are glossy greenish-black, while its mantle, upper back, neck sides, lower throat, upper breast, covert feathers, and secondary feathers are dull green. Its crown is black, and the bare skin around its eyes are hues of green, lilac, and blue. Its bill and legs are green, and its underparts below the upper breast are cinnamon buff. BirdLife International describes its voice as follows: "Repeated low whistles (falling then rising in tone: WE-ow-WE), plus issued in a rising series (we-ow-we, we-ow-we, we-ow-we, we-ow-we; each phrase slightly higher than last)."

The Sumatran ground cuckoo is endemic to the Indonesian island of Sumatra. Notes on early specimen labels as well as recent sightings suggest its favoured habitat is foothills and primary montane forest. It has been found between elevations of 300 and 1,400 m (975 and 4,600 ft), although recent sightings are exclusively from 800–1,000 m (2,600–3,300 ft). Its small population makes it difficult to find, and like the Bornean ground cuckoo, it may exhibit unobtrusive behavior – making sightings even more rare. Most modern-day sightings have taken place in the Barisan Mountains in South Sumatra and the Kerinci Seblat National Park of Jambi province, beginning with an individual photographed in Bukit Barisan Selatan National Park in 1997. An additional unconfirmed sighting took place in the Bukit Rimbang-Baling Wildlife Sanctuary in 2000. In 2007, its call was recorded for the first time by Wildlife Conservation Society biologists after a trapper handed them a bird he had caught. Up to five more sightings were reported nearby between 2007 and 2010. In 2017, a camera trap in Batang Gadis National Park took a photo of a Sumatran ground cuckoo, indicating that a previously unknown population may exist in North Sumatra.