Sumatran Frogmouth Batrachostomus poliolophus Scientific name definitions

20–22 cm. A sexually dichromatic species, with no apparent polymorphic variation in coloration; sexes confused in early accounts. Male dull dark rufescent-brown with buffish-white collar across upper mantle, and bold white spots on scapulars and wing-coverts; breast with white scallop-shaped markings, flanks and belly whitish with brownish edges to feathers. Differs from other small, sexually dichromatic Batrachostomus in combination of relatively short tail and details of coloration (as well as sub-montane distribution). Female brighter, deep rufous to chestnut, with reduced white spotting, and often narrower collar. Juvenile plumage unknown.

Formerly considered conspecific with B. mixtus but that species has extensive white on underparts (3), male has a paler crown (2) and female is much less contrastingly rufous (2). Monotypic.

Mountains of Sumatra (Barisan Range).

Sub-montane primary forest and mixed pine forest. Generally tends to occur at somewhat higher altitudes than other Batrachostomus: recorded at 600–1400 m in Sumatra. 

No information, but presumably sedentary like its congeners.

Gut contents of specimens examined included remains of small beetles and small Orthoptera.

Only very recently described, for both races. Song (perhaps call) said to be a fairly loud undulating whistle, rising in pitch, followed by 5–7 descending liquid notes. Song (or call) of mixtus described as a whistled “weeow” repeated at c. 3-second intervals, each note sometimes wavering towards end; also high-pitched “chiok, chiok, chiok” series, perched or in flight, possibly as alarm.

Few data. Known mainly from a single nest found in Sumatra in Jun 1933: a small pad with shallow cup, built mainly of down from birds’ underparts, placed c. 5 m above ground at fork of inclined branch of a sapling; it held 1 partly incubated egg, and the male incubated during the daytime. Fledgling accompanied by adult male recorded in early Jul.

Not globally threatened. Currently considered Near Threatened; previously Data Deficient. A restricted-range species that is reported as uncommon. The Sumatran lowlands have suffered extensive deforestation but since this species also ranges to higher elevations it may be that it is not suffering more than a moderately rapid decline. Nevertheless, deforestation in the lower part of its altitudinal range is a threat, even within the protected areas in its range, such as Kerinci-Seblat National Park. Its voice, however, is still poorly known, having only recently been described, so that its true status is difficult to judge.