The toque macaque (Macaca sinica) is a reddish-brown-coloured Old World monkey endemic to Sri Lanka, where it is known as the rilewa or rilawa (Sinhala: රිළවා), (hence "rillow" in the Oxford English Dictionary). Its name refers to the whorl of hair at the crown of the head, reminiscent of a brimless toque cap.

The generic name Macaca is from Portuguese macaco, of unclear origin, while sinica means "of China," even though the species is not found there.

There are three recognized subspecies of toque macaques:

• Macaca sinica sinica, dry zone toque macaque or common toque macaque

• Macaca sinica aurifrons, wet zone toque macaque or pale-fronted toque macaque

• Macaca sinica opisthomelas, highland toque macaque or hill zone toque macaque

M. s. opisthomelas is similar to subsp. aurifrons, but has a long fur and contrasting golden color in the anterior part of its brown cap.

The three subspecies can be identified their head colour patterns.

• M. s. sinica is found from the Vavuniya, Mannar to the lowlands of Anuradhapura, Polonnaruwa, Puttalam, and Kurunegala; and along the arid zone of the Monaragala and Hambantota districts.

• M. s. aurifrons can be found sympatrically with the subspecies M. s. sinica within intermediate regions of the country in Kegalle and parts of Kurunegala. It is also found in south-western parts of the island in the Galle and Matara districts near Kalu Ganga.

• M. s. opisthomelas has recently been identified as a separate subspecies. It can be found in the entire south-western region of Ratnapura and in the Nuwara Eliya districts. It is also found around Hakgala Botanical Garden and other cold climatic montane forest patches.

The toque macaque is listed as Endangered by the International Union for the Conservation of Nature (IUCN) due to habitat destruction and hunting, and also for the pet trade. Much of the original forested habitat of the toque macaque has been lost, between 1956 and 1993 50% of Sri Lanka's forest cover was destroyed. Plantations and fuel wood collection have been the main drivers of habitat lost. Toque macaques were also used by both Sri Lanka Army and Tamil Tigers as target practice during the Sri Lankan Civil War.

Wet Zone Toque Macaque (Macaca sinica aurifrons) Singharaja National Park, Sri Lanka

Highland Toque Macaque (Macaca sinica opisthomelas) Nuwara Eliva Sri Lanka

Dry Zone Toque Macaque (Macaca sinica sinica) Srigiriya Forest and Fortress Sri Lanka