The New World primate family Callitrichidae includes seven genera of marmosets, tamarins, lion tamarins and callimico. They are small, arboreal, diurnal, insectivore/frugivores of the forests, chaco, and scrub of tropical Central and South America. Some 60 species and subspecies of the family Callitrichidae are now recognized, 22 of which are considered to be marmosets, the “short-tusked” genera with dental and behavioral adaptations for tree-gouging and exudate-feeding. The marmosets are divided into four taxonomic groups, which we recognize as genera: Callithrix (eastern Brazilian marmosets of the Jacchus-group), Cebuella (the Amazonian pygmy marmosets), Callibella (the Amazonian dwarf marmoset), and Mico (the Amazonian marmosets of the Argentata-group). Studies over the last decade have demonstrated that Goeldi’s monkey or callimico is a sister species to these marmosets. Here we review the most recent information concerning the taxonomy of these 23 species and what is known of their geographic distributions in the wild.

https://www.springer.com/cda/content/document/cda_downloaddocument/9781441902924-c1.pdf?SGWID=0-0-45-878345-p173893535

The Systematics and Distributions of the Marmosets (Callithrix, Callibella, Cebuella, and Mico) and Callimico (Callimico) (Callitrichidae, Primates)

We carried out a 4-month census of primates in the Pando Department of northern Bolivia with special emphasis on Saguinus species. Contrary to a previous report by Izawa and Bejarano (1981), there was no evidence for the presence of the two populations of Saguinus mystax that they reported, or that Lagothrix occurs in the Pando. In addition, we found the distribution of Saguinus imperator to be more restricted than they suggested. We confirm the presence of Cebuella south of the Rio Tahuamanu (cf. Brown and Rumiz, 1986) and report two new locations for Callimico goeldii. We present data on group sizes, habitat utilization, and locomotor behavior of the primates and compare them with previous studies in the Pando. Differences in body size, diet, foraging techniques, and vertical use of the forest appear to be key factors in both sympatry and in the formation of polyspecific associations.

Distribution and forest utilization of Saguinus and other primates of the Pando Department, Northern Bolivia

Special issue: Comparative biogeography of Neotropical primates.

Primates were surveyed at two sites in the Xingu-Tocantins interfluvium, in eastern Amazonia, where at least eight platyrrhines are known to occur, including the endemic Chiropotes satanas utahicki, vulnerable to extinction. Only three other forms; Alouatta belzebul belzebul, Cebus apella apella, and Saguinus midas niger; were recorded at both sites. Data on habitat use (forest type and strata) were collected in standard line transect surveys and analyzed with relation to the availability of forest types, as well as between sites and species. The smallest- (S. midas) and largest-bodied (A. belzebul) species were relatively common at the continuous forest site, where they exhibited a significant preference for primary terra firme forest. At this site, Cebus demonstrated a significant preference for liana and flooded forest in contrast with primary or secondary terra firme forests. The medium-sized Cebus and Chiropotes were more common in the isolated forest fragment (where they were also observed together frequently), but no clear habitat preferences were found at this site for any species. A. belzebul occupied significantly higher forest strata than other species, which all used relatively similar levels. C.s. utahicki was active in much lower forest strata than other bearded sakis, whereas S. midas was observed at much higher levels than at other sites in eastern Amazonia. It remains unclear whether and to what extent observed patterns are determined by differences between taxa, populations, or ecosystems, but the data indicate that C.s. utahicki is relatively tolerant of habitat disturbance.

Habitat use by Chiropotes satanas utahicki and syntopic platyrrhines in eastern Amazonia

A new species of titi monkey, genus Callicebus Thomas, 1903, is described based on four individuals, one from a small tributary of the left bank of Rio Teles Pires, northern state of Mato Grosso, and three others from Largo do Souza, Rio Iriri, Para, Brazil. The new species belongs to the Callicebus moloch species group, and the main diagnostic characteristics of the new species are the whitish forehead, sideburns and beard coloration, which are contiguous, forming a frame around the blackish face; overall body pelage coloration is pale grayish-brown agouti; hands, feet and tip of the tail whitish; belly and inner sides of fore and hind limbs uniformly orange. The pattern of pelage coloration and qualitative and quantitative skull morphology are described and compared to the other species of the Callicebus moloch group. Species of the Callicebus moloch group show great similarity in skull morphology and morphometrics, making the external morphological characters, specially the chromatic fields, the most reliable diagnostic trait to identify the species.

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A new species of Callicebus Thomas, 1903 (Primates, Pitheciidae) from the states of Mato Grosso and Pará, Brazil

Five species of titi monkey (Callicebus brunneus, Callicebus caligatus Callicebus cinerascens, Callicebus donacophilus, andCallicebus moloch) were recorded in surveys of primate populations at 26 sites throughout the Brazilian state of Rondonia. The distribution of the two species,C. cinerascens andC. donacophilus (recorded in the state for the first time), appeared to be related to that of non-forest ecosystems, the former in thecerrado woodlands, and the latter in gallery forests of the Guapore grasslands. The results of the surveys also indicate thatC. brunneus has a more restricted distribution in southern Rondonia than was previously thought, whereasC. moloch is more widespread. However, the ecological factors that determine species distribution in the south of the state remain unclear on the basis of the available data. All species were observed in small social groups of no more than five individuals, which are typical of the genus, generally in the middle and lower forest strate.

Titi monkeys (Callicebus spp., Atelidae : Platyrrhini) in the Brazilian state of Rondonia

White-nosed bearded sakis (Chiropotes albinasus) are endemic to the Madeira–Xingu interfluvium in southern Amazonia, though recent fieldwork has produced conflicting data on the southwestern limits of the species's geographic range. We reevaluated the distribution of bearded sakis on the basis of surveys from 34 sites throughout the Brazilian state of Rondonia. Chiropotes albinasus occurred at seven sites in the eastern part of the state, including two west of the Jiparana–Pimenta Bueno river system in the extreme south, but there is no record of their presence further north and west in the Jiparana–Guapore interfluvium and they were absent from the Jiparana–Mamore interfluvium. The data suggest that ecological, rather than geographic barriers restrict the distribution of Chiropotes albinasus in southern Rondonia, but are contradictory with regard to the possible determining factors. Chiropotes albinasus appears able to thrive in transitional, savanna-like ecosystems in southern Rondonia, but is unexpectedly absent from adjacent areas of terra firme forest. Syntopy with the only other pitheciine found in the state (Pithecia irrorata) appears to have a negative effect on the abundance of Chiropotes albinasus which implies that interspecific competition may reinforce a complex of limiting factors, such as the availability of key plant species. Despite showing that Chiropotes albinasus is widespread in southern Rondonia, we also confirm its absence from the western two thirds of the state, a significant reduction in the known range of the species.

Ernesto H. da Cruz Neto

Papers

Titi monkeys (Callicebus spp., Atelidae : Platyrrhini) in the Brazilian state of Rondonia

Zoogeography of Chiropotes albinasus (Platyrrhini, Atelidae) in Southwestern Amazonia

Expansion of the known distribution of Goeldi's monkey (Callimico goeldii) in south-western Brazilian Amazonia