Cheracebus torquatus

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Cladus: Sarcopterygii
Cladus: Rhipidistia
Cladus: Tetrapodomorpha
Cladus: Eotetrapodiformes
Cladus: Elpistostegalia
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Cladus: Synapsida
Cladus: Eupelycosauria
Cladus: Sphenacodontia
Cladus: Sphenacodontoidea
Cladus: Therapsida
Cladus: Theriodontia
Cladus: Cynodontia
Cladus: Eucynodontia
Cladus: Probainognathia
Cladus: Prozostrodontia
Cladus: Mammaliaformes
Classis: Mammalia
Subclassis: Trechnotheria
Infraclassis: Zatheria
Supercohors: Theria
Cohors: Eutheria
Infraclassis: Placentalia
Cladus: Boreoeutheria
Superordo: Euarchontoglires
Ordo: Primates
Subordo: Haplorhini
Infraordo: Simiiformes
Parvordo: Platyrrhini

Familia: Pitheciidae
Subfamilia: Callicebinae
Genus: Cheracebus
Species: Cheracebus torquatus

The collared titi monkey (Cheracebus torquatus) is a species of titi, a type of New World monkey. It is endemic to northern Brazil.[2]
Taxonomy

At the end of the 1980s the genus Callicebus was revised from the Hershkovitz concept of three species[3] to thirteen neotropical species, with the collared titi, Callicebus torquatus, having four subspecies.[4][5] In 2001 Colin Groves elevated one of the subspecies, the Colombian black-handed titi, C. t. medemi, to Callicebus medemi and a year later Van Roosmalen et al. elevated the remaining subspecies to species.[6][7] These last changes were made with few arguments to support the changes and were apparently influenced by the increasing use of the so-called phylogenetic species concept of Cracraft, which seeks to define species as the "smallest diagnosable cluster of individual organisms within which there is a parental pattern of ancestry and descent."[8]

The species complex was updated to Cheracebus in 2016. The recent discovery of a diploid number of 16 for the black titi, Cheracebus lugens, in Brazil suggested that (with the previously known 2n=20 of another, unidentified population of C. torquatus) there are at least two species in this complex.[9] But whether the Lucifer titi, Cheracebus lucifer, or the Colombian black-handed titi, Cheracebus medemi, were good species from this complex was in doubt.[10] However, a 2020 study prove them to be distinct species from C. torquatus. However, the same study found the Rio Purus titi (C. purinus), previously thought to be endemic to Brazil, to be conspecific with the collared titi, with the type locality and specimen of C. torquatus being from populations attributed to C. purinus; thus, C. purinus was synonymized with C. torquatus. The American Society of Mammalogists and ITIS follow this synonymization, but the IUCN Red List retains it as a distinct species, classifying it as a species of least concern.[11][12][13][14]
Physical description

Five adults weighed an average of 1462 g (range 1410–1722 g) with a head-body length of around 290–390 mm and a tail length of about 350–400 mm.[4] The face has very little hair, being limited to sparse short white hairs over a black skin. There is no sexual dimorphism, although the male has canines a bit longer than the female. The species has the smallest karyotype known for primates, 2n=16 recently described by Bonvicino et al.[15]

The pelage is typically uniformly reddish brown or blackish brown. The tail is blackish mixed with some reddish hairs with hands and feet whitish or dark brown. This pelage contrasts in all of the subspecies with a band of white hair which extends upward from the chest and follows the neck, prolonging itself to the ears. This extension to the ears is weak, different from the other Cheracebus species which have white extending to the base of the ears.
Geographic distribution and habitat

This species is thought to be restricted to Brazil, although it may range into adjacent Colombia. It is found south to the Tapauá River or potentially the Pauiní River, west to the Apaporis and Vaupés rivers, north to the Uaupés River and Rio Negro, and as far east as the town of Manacapurú. If it ranges into Colombia, it may potentially hybridize with the black titi (C. lugens) where their ranges overlap.[14][16]

The collared titi is seen most frequently in well-developed, tall forest with a closed canopy, usually over terra firme, but not exclusively so. The species also enters extensive várzea forest, especially if the forest is tall and well-developed.[17] Such várzea forest contrasts with the habitat needs of the coppery titi, which also uses várzea forest and more commonly so. But the coppery titi survives in low, vine-covered, "poor" forest where the collared titi is rarely found.
Conservation status

The collared titi is not considered to be endangered, but where there are many colonists this primate tends to disappear, due to deforestation. The species is commonly hunted and eaten by indigenous peoples or used as bait for hunting larger carnivores or for fishing; however, where there is plenty of forest meat the species is found commonly close to indigenous settlements. The species is classified Least Concern (formerly LR) in the IUCN Red List.[1]
References

Veiga, L.M. & Boubli, J.-P. (2008). "Cheracebus torquatus". IUCN Red List of Threatened Species. 2008: e.T41562A10499183. doi:10.2305/IUCN.UK.2008.RLTS.T41562A10499183.en.
Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. p. 146. ISBN 0-801-88221-4. OCLC 62265494.
Hershkovitz, P (1963): A systematic and zoogeographic account of South American titi monkeys, genus Callicebus (Cebidae) of the Amazonas and Orinoco river basins, Mammalia, 27(1):1-80.
Hershkovitz, P (1990): Titis, new world monkeys of the genus Callicebus (Cebidae, Platyrrhini): a preliminary taxonomic review, Fieldiana (Zoology, New Series, no. 55):1-109-
Hershkovitz, P. (1988): Origin, speciation, dispersal of South American titi monkeys, genus Callicebus (family Cebidae, Platyrrhini), Proceedings of the Academy of Natural Sciences of Philadelphia, 140(1):240-272.
Groves 2001
Van Roosmalen, M.G.M.; Van Roosmalen, T.; Mittermeier, R.A. (2002). "A taxonomic review of the titi monkeys, genus Callicebus Thomas, 1903, with the description of two new species, Callicebus bernhardi and Callicebus stephennashi from the Brazilian Amazon" (PDF). Neotropical Primates. 10 (Suppl): 1–52. Archived from the original (PDF) on 2012-01-23. Retrieved 2011-01-23.
Cracraft 1983, pp. 159–187
Barros, R. M. S.; Pieczarka, J. C.; Brigido, M. D. C. O.; Muniz, J. A. P. C.; Rodrigues, L. R. R.; Nagamachi, C. Y. (2004). "A new karyotype in Callicebus torquatus (Cebidae, Primates)". Hereditas. 133 (1): 55–8. doi:10.1111/j.1601-5223.2000.t01-1-00055.x. PMID 11206854.
Defler 2010
Byrne, H.; Rylands, A. B.; Nash, S. D.; Boubli, J. P. (2020). "On the taxonomic history and true identity of the collared titi, cheracebus torquatus (Hoffmannsegg, 1807) (Platyrrhini, Callicebinae)" (PDF). Primate Conservation. 34: 13–52. ISSN 0898-6207.
Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. p. 145. ISBN 0-801-88221-4. OCLC 62265494.
Byrne, Hazel; Rylands, Anthony B.; Carneiro, Jeferson C.; Alfaro, Jessica W. Lynch; Bertuol, Fabricio; da Silva, Maria N. F.; Messias, Mariluce; Groves, Colin P.; Mittermeier, Russell A. (2016-01-01). "Phylogenetic relationships of the New World titi monkeys (Callicebus): first appraisal of taxonomy based on molecular evidence". Frontiers in Zoology. 13: 10. doi:10.1186/s12983-016-0142-4. ISSN 1742-9994. PMC 4774130. PMID 26937245.
Boubli, Jean P.; Fialho, Marcos de Souza (2015-01-26). "IUCN Red List of Threatened Species: Cheracebus purinus". IUCN Red List of Threatened Species.
Bonvicino, C. R.; Penna-Firme, V. E. R.; Do Nascimento, F. I. C. F.; Lemos, B.; Stanyon, R.; Seuánez, H. E. C. N. (2003). "The Lowest Diploid Number (2n=16) yet Found in Any Primate: Callicebus lugens (Humboldt, 1811)". Folia Primatologica. 74 (3): 141–149. doi:10.1159/000070647. PMID 12826733. S2CID 32922523.
Martins, Amely B.; Boubli, Jean P.; Erwin Palacios (Conservación Internacional Colombia, Bogotá (2015-01-26). "IUCN Red List of Threatened Species: Cheracebus torquatus". IUCN Red List of Threatened Species.

Defler, 1994a

Books cited

Hernández-Camacho, J.I.; Cooper, G.W. (1976). "The non-human primates of Colombia". In Thorington, R.W. Jr.; Heltne, P.G. (eds.). Neotropical Primates: Field Studies and Conservation. Washington, D. C.: National Academy of Sciences. pp. 35–69. ISBN 978-0-309-02442-6.
Cracraft, J. (1983). "Species concepts and speciation analysis". In Johnston, R.F.; Power, D.M. (eds.). Current Ornithology. Vol. 1. New York: Plenum Press. pp. 159–187. ISBN 978-0-306-41780-1. OCLC 181794456.
Defler, T.R. (2010). Historia Natural de los Primates Colombianos [Natural History of the Colombian Primates]. Bogotá, Colombia: Universidad Nacional de Colombia.
Groves, C.P. (2001). Primate Taxonomy. Smithsonian Institution Press. ISBN 978-1-56098-872-4.