Wallace et al., 2006
Callicebus aureipalatii
Type locality: Campamento Roco Roco, Río Hondo, Madidi N.P. and Natural Area of Integrated Management, La Paz Department, Bolivia (14º37′30″S, 67º43′06″W). The type specimens were deposited in the Colección Boliviana de Fauna, part of the Museo Nacional de Historia Natural based in La Paz, Bolivia.
Distribution: Callicebus aureipalatii was present at four of the line transect survey sites: Río Tuichi, Río Hondo, Alto Madidi, and Río Undumo. The literature review revealed a further 15 sites in the immediate vicinity of the known distribution where an unidentified Callicebus had been registered: Chalalán, Tumupasa, Capaina, Buena Vista, Santa Fe, Carmen Pecha, Bella Altura, Napashi, Santa Rosa de Maravilla, Altamarani, San Antonio de Tequeje, Carmen del Emero, Esperanza de Enapurera, Tres Hermanos, and Cachichira (Sarmiento et al. 2001; CIPTA/WCS, unpubl. data). According to our surveys, Callicebus aureipalatii is found exclusively on the western side of the Río Beni, a major tributary of the Amazon and one of the largest rivers in Bolivia. The known and hypothetical distribution of this species is shown in the figure. In addition, literature and structured informal interviews with local indigenous communities along the Río Quiquibey suggest that the genus Callicebus is now absent from most of the Pilon Lajas Biosphere Reserve and IndigenousTerritory. Nevertheless, a group of unidentified Callicebus monkeys were heard calling in the Sani vicinity (14º35′41″W, 67º29′47″S) of Pilon Lajas in March 2003.
The northern range limits for C. aureipalatii are currently unknown and we predict that they may reach as far as the southern bank of the Río Madre de Dios. Current knowledge indicates that Callicebus aureipalatii is distinct from populations north of the Madre de Dios, where animals do not display a golden crown or deep orange throat coloration. These populations have previously been considered to be C. brunneus (Hershkovitz 1988), although Van Roosmalen et al. (2002, see Figure 1, pp.5) classified them as C. dubius. Recent primate surveys in the Cobija region of Pando have photographed Callicebus displaying a white-tipped tail but with no golden crown, and Pando monkeys also lack the characteristic C. dubius white stripe across the forehead (Sandra Suarez, pers. comm., Noel Rowe, pers. comm.).
Description: A species of the C. moloch group (sensu Hershkovitz 1990; Groves 2001) as defined according to broad distributional and physical characteristics. Using the Van Roosmalen et al. (2002) classification, this new species shows physical similarities with the C. cupreus group (crown and cheiridia dominated by pheomelanin hair pigments, orange ventrally sharply contrasting with agouti body coloration, cheiridia reddish), however, available information on distribution suggests it borders C. brunneus (a member of the C. moloch group according to Van Roosmalen et al. 2002) to the north. This species is distinguished by a golden crown due to golden tipped hairs with dark longer base, dark forehead with slightly less golden coloration; deep orange throat and ventral area; deep orange burgundy limbs from elbow and knees to hands and feet; dark tail with clear paler whitish tip. Distinguished from C. brunneus by a distinct golden coloration on the crown, deep orange throat coloration; sharply contrasting sideburns and underside, and orange to burgundy cheiridia; from C. cupreus by a distinct golden coloration on the crown and deep orange throat coloration, and from C. dubius by a distinct golden coloration on the crown, deep orange throat coloration, and lack of the white forehead stripe. C. olallae, C. modestus, and C. donacophilus, all members of the C. donacophilus species group (Van Roosmalen et al. 2002) and found exclusively on the eastern side of the Río Beni, display clear white ear tufts and are characterized by a uniform dorsal and lateral body colour. These taxa lack differential crown coloration and contrasting lateral coloration on the limbs, and are characterized by a uniformly coloured tail with no obvious white tip.
Description of holotype: Dorsal and lateral body to neck, lateral forelimbs to elbow and lateral hind-limbs to knee light brown non-uniform colour due to agouti-banded hairs that are grey brown at the basal half, then changing to banded grey brown with lighter brown, and ending in a light brown tip. Laterally, forelimbs and hind limbs from elbows and knees colours gradually change to deep orange burgundy through initial mixing of orange hairs. At hands colour change becomes more definite to a deep burgundy and these hairs lightly cover hands dorsally. Feet very thickly covered with dark burgundy coloured hair. Body ventrally pale orange largely due to low hair density. Hair density increases from groin area toward abdominal and chest regions, considerably denser at neck. Ventral hairs are a deep orange colour that deepens as hair density increases and extends to cheek regions as far as the base of the ear. Forelimbs and hind limbs ventrally the same orange colour as far as the feet where the colour deepens slightly in the hands and more strikingly in the feet. Tail brown to black dorsally, paler black to light brown ventrally with banded hairs (pale base and dark tip). Tip of tail clearly whitish pale with white hairs at very tip (female specimen hairs c.52 mm long and male specimen c.81 mm). Crown extending to an area just above ears shows clearly defined golden tipped c.16 mm hairs that are banded in dark and light brown phases at the base with a c.4.5 mm golden tip. Forehead appears slightly darker due to shorter hairs (c.9.5 mm) with smaller golden portions. No clear line distinguishing crown area. Facial skin black with a few whitish hairs in the nasal region; whiskers and eyebrows black; paler ears with hairs on tops of ears golden tipped and hair around ear orange; pupils black and irises coffee coloured. During transect observations, filming and collection activities in more than 15 different social groups only one animal showed variation to the holotype description above, being slightly paler.
Measurements:
Male: Head and body 817mm; tail 524mm; hind foot 102mm
Female: Head and body 800mm; tail 480mm; hind foot 93mm
Skull and further measurements: see publication
The full text of this description can be found at:
http://www.primate-sg.org/PDF/PC20.Callicebus.nov.pdf
Vermeer, 2009
Callicebus aureipalatii
Remarks: The animals living at the Los Amigos Research Station near the Madre de Dios, Peru (12° 34' S, 70° 06'W) and at Tambopata are usually identifed as being Callicebus brunneus, and they indeed resemble the drawing of this species in the publication of van Roosmalen et al. (2002). However, when comparing them to the type specimens of this species they are considerably different, and the titi monkeys in this area are most probably Callicebus aureipalatii (Wallace et al. 2006). Individuals of Callicebus aureipalatii were also observed by the author in the eastern part of Manu National Park, Peru (Pantiacolla Lodge, 12° 39'S, 71° 13' W). However, the situation in this area is quite confusing, as other animals were much darker, resembling a transitional coloration between Callicebus aureipalatii and Callicebus brunneus. Very dark animals in the collection of the Natural History Museum in Lima resemble Callicebus brunneus very closely, and were collected at Quebrada Aguas Calientes in ManuNational Park. More research is urgently needed on the identification of the titi monkeys in and around Manu National Park.
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