Sixteen bird species are found endemic to Sumatra, and an additional 10 are Restricted Range Species (i.e., with a global breeding range of less than 50,000 km2). A total of 78 montane species have been recorded so far, which is 76% of the total montane Sumatran avifauna (n=103).
Nineteen species were migratory birds from the northern hemisphere, using the Batang Toru are as a passage area, or as wintering quarters. Amongst these scarce species as Ferruginous Flycatchers Muscicapa ferruginea and a possible species new to Sumatra Two-barred Warbler Phylloscopus plumbeitarsus (still to be confirmed).
Six Globally Vulnerable species were found: Wallace’s Hawk-eagle Spizaetus nanus and Blue-banded Kingfisher Alcedo euryzona, Graceful Pitta Pitta venusta, Sumatran Laughing-thrush Garrulax bicolor, and Large-billed Blue Flycatcher Cyornis caerulatus. An additional 58 Globally Near-threatened species were recorded.