Callicebus dubius, Hershkovitz, 1988

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Phitheciidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 432-483 : 462

10.

Doubtful Titi

Callicebus dubius

French: Titi de Hershkovitz / German: Hershkovitz-Springaffe / Spanish: Titi de Hershkovitz

Other common names: Doubtful Titi Monkey, Dubious Titi, Hershkovitz's Titi, Hershkovitz's Titi Monkey

Taxonomy. Callicebus dubius Hershkovitz, 1988 ,

Lago do Aiapua [= Ayapua], modified by Hershkovitz in 1990 as more likely “the east bank of the lower Rio Purus probably opposite Lago do Aiapua.”

In their 2002 review of the genus, M. van Roosmalen and coworkers argued that C. dubius does not occur along the Rio Purus in the vicinity of the Lago do Aiapua, but only between the rios Madeira and Purus south of either the Rio Ituxi or the Rio Mucuim (right bank tributaries of the Purus). This being true would invalidate the type locality proposed by Hershkovitz. C. cupreusand C. purinus occur on the west (left) bank of the Rio Purus, and it is unlikely there would be a third titi occurring there. In 2001, C. P. Groves considered C. dubius to be a synonym of C. cupreus , but in 2005 he listed it as a full species, agreeing with the 1990 revision by P. Hershkovitz. C. dubiusis a member of the C. cupreus species group. Its distribution may contact or intergrade with that of C. stephennashi in the vicinity of the Rio Mucuim. Monotypic.

Distribution. W Brazilian Amazon, between upper rios Purus, Ituxi, and Mucuim (the latter two rivers are right bank tributaries of the Purus) in the N, and the Madeira-Abuna river system to the S, in the states of Amazonas, Acre, and Rondonia; this species occurs as far S as the Rio Abuna, but the limits ofits distribution to the S and W are not known.

Descriptive notes. Head—body 37 cm (males) and 37-40 cm (females), tail 47 cm (males) and 39-44 cm (females); weight ¢.800 g as in other titis in the cupreus group. Male and female Doubtful Titis are indistinguishable in size or coloration. Their bodies, crowns, and proximal one-third of their tail are brownish-agouti. Distal two-thirds of tail is blackish, with contrasting white penciling. Sideburns and beards are deep reddish. Underparts and inner surfaces of limbs are reddish to reddish-brown. Outer surfaces of forearms and lower legs are reddish. Hands and feet are blackish-agouti, but digits are contrasting pale buffy or white. Forehead has a buffy or whitish frontal blaze, bordered below by a narrow blackish line connecting ears.

Habitat. Lowland Amazon rainforest at elevations of 100-400 m.

Food and Feeding. There is no information available for this species.

Breeding. There is no specific information available for this species, but all titis form monogamous breeding pairs. The male provides parental care by carrying the single offspring.

Activity patterns. There is no information available for this species.

Movements, Home range and Social organization. Groups of up to four Doubtful Titis have been observed at two sites in Rondonia, indicating that the social organization is typical of the titis in general, with groups composed of a breeding pair and their immature offspring.

Status and Conservation. CITES Appendix II. Classified as Least Concern on The [UCN Red List. The Doubtful Titi is endemic to a relatively remote region of the Amazon Basin and is under no immediate threat.

Bibliography. Ferrari et al. (2000), Hershkovitz (1988, 1990), Rohe & Silva (2009), Rowe & Martinez (2003), Norconk (2011), Veiga (2008d).

Figures

On following pages: 4. Olallas’ Titi (Callicebus olallae); 5. San Martin Titi (Callicebus oenanthe); 6. Coppery Titi (Callicebus cupreus); 7. Red-crowned Titi (Callicebus discolon; 8. Ornate Titi (Callicebus ornatus); 9. Chestnut-bellied Titi (Callicebus caligatus); 10. Doubtful Titi (Callicebus dubius); 11. Stephen Nash's Titi (Callicebus stephennashi); 12. Caqueta Titi (Callicebus caquetensis);, 13. Ashy Titi (Callicebus cinerascens); 14. Hoffmanns's Titi (Callicebus hoffmannsi); 15. Lake Baptista Titi (Callicebus baptista); 16. Red-bellied Titi (Callicebus moloch).

Distribution. W Brazilian Amazon, between upper rios Purus, Ituxi, and Mucuim (the latter two rivers are right bank tributaries of the Purus) in the N, and the Madeira-Abuna river system to the S, in the states of Amazonas, Acre, and Rondonia; this species occurs as far S as the Rio Abuna, but the limits ofits distribution to the S and W are not known.