Decken's Sifaka is a lemur of northwestern Madagascar's dry deciduous forests and limestone tsingy. Its ivory fur contrasts with dark skin.
Its fur is light ivory, while its skin is black.
Species-specific observations report it descending to the ground more often than other sifakas. Groups described in the source numbered 2–5; this is the range of reported observations.
An extinction-risk assessment has not been added yet.