The East Sumatran banded langur (Presbytis percura), also known as the East Sumatran banded surili, is a species of monkey in the family
Cercopithecidae. It was formerly considered a
subspecies of the
Raffles' banded langurPresbytis femoralis, but genetic analysis revealed it to be a separate species.[2][3][4][5] Its range is restricted to the
Riau Province of east-central
Sumatra.[2][6] Due to its declining population and restricted range in small, isolated forests subject to high rates of
deforestation,[2] the IUCN declared it to be a
critically endangered species in 2020.[1]