Callicebus aureipalatii, Wallace & Gómez & Felton & Felton, 2006

Wallace, Robert B., Gómez, Humberto, Felton, Annika & Felton, Adam M., 2006, On a New Species of Titi Monkey, Genus Callicebus Thomas (Primates, Pitheciidae), from Western Bolivia with Preliminary Notes on Distribution and Abundance, Primate Conservation 20, pp. 29-39 : 31-36

Callicebus aureipalatii sp. nov.

Holotype: Adult male, skin, skull and complete skeleton (CBF7511, Collectors: Robert Wallace, Rodolfo Nallar, Jesús Martínez, Fortunato Espinoza, Lucio Ocampo and Remberto Chiguapuri, 2003). Colección Boliviana de Fauna, Museo Nacional de Historial Natural, La Paz, Bolivia. Collected 27 February 2003 on the northern bank of the Río Hondo (14º37 ′ 59 ″ W, 67º42 ′ 27 ″ S).

Paratype: Adult female, skin, skull and complete skeleton (CBF7510, Collectors: Robert Wallace, Rodolfo Nallar, Jesús Martínez, Fortunato Espinoza, Lucio Ocampo and Remberto Chiguapuri, 2003). Colección Boliviana de Fauna, Museo Nacional de Historial Natural, La Paz, Bolivia. Collected 25 February 2003 on the southern bank of the Río Hondo (14º38 ′ 23 ″ W, 67º42 ′ 27 ″ S).

Type locality: Campamento Roco Roco, Río Hondo, Madidi National Park and Natural Area of Integrated Management, La Paz Department, Bolivia (14º37 ′ 30 ″ S, 67º43 ′ 06 ″ W).

Diagnosis: 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 ( Figs. 2– 6 ). 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 color. These taxa lack differential crown coloration and contrasting lateral coloration on the limbs, and are characterized by a uniformly colored tail with no obvious white tip.

External characteristics of holotype: Dorsal and lateral body to neck, lateral forelimbs to elbow and lateral hind-limbs to knee light brown non-uniform color 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 colors gradually change to deep orange burgundy through initial mixing of orange hairs. At hands color change becomes more definite to a deep burgundy and these hairs lightly cover hands dorsally. Feet very thickly covered with dark burgundy colored 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 color 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 color as far as the feet where the color 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 colored. 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: See Tables 2 and 3 .

Etymology: This species is named Callicebus aureipalatii in recognition of a major financial contribution from GoldenPalace.com to FUNDESNAP (Foundation for the Development of the National Protected Area System). This funding will go exclusively toward the long-term conservation of the Madidi National Park and Natural Integrated Management Area where the species was discovered.

Vernacular Name: This species is locally known by the generic names for titi monkeys in the region — luca luca or lucachi. The company GoldenPalace.com refers to the monkey as the GoldenPalace.com monkey, and other English names currently in use include the golden palace monkey and the Madidi titi monkey.

Geographic Distribution: Callicebus aureipalatii was present at four of the line transect survey sites: Río Tuichi, Río Hondo, Alto Madidi, and Río Undumo (see Fig. 1 ). 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 Figure 1 . 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 Indigenous Territory ( Barrera et al. 1994; Rumiz and Townsend 1999) apparently wiped out because of its use as fishing bait (Ascensión de Quiquibey, pers. comm.). 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 (F. Espinoza, pers. comm.).

Habitat: The Río Tuichi and Río Hondo valleys are adjacent tributaries of the Río Beni and are enclosed by the last foothills of the Andes in northwestern Bolivia. The region is characterized by a marked dry season between April and November with annual precipitation of approximately 2,230 mm. Vegetation appears similar to that of the Beni alluvial plain forests found at the base of the Andes in this region. The forest is characterized by relatively open canopies with a large proportion of palms such as Iriartea deltoidea , Scheelea princeps , Astrocaryum sp. , Socratea exhorriza , and Jessenia , as well as large emergent and canopy tree species such as Ceiba pentandra , Sterculia sp. , Cabralea canjerana , Rinorea viridifolia , Pseudolmedia sp. , and Pentaplaris davidsmithii ( Flores et al. 2002; pers. obs.). Callicebus aureipalatii has been observed in the lowland plain forests of the Río Tuichi and Río Hondo valleys and the Alto Madidi lowlands, as well as the piedmont or foothill forests of the region in the Río Tuichi, Río Hondo, Alto Madidi, and Río Undumo study sites. Sightings to date are altitudinally distributed between 200 and 500 m a.s.l., although surveys are lacking in the humid tropical forests between 500 and 1,000 m a.s.l. that might be suitable habitat for Callicebus . Based on distributional and habitat use data we used a simple GIS model using habitat type, potential river boundaries, and elevation to provide a preliminary estimation of potential habitat for C. aureipalatii ( Fig. 1 ). A total of 4,256 km² were estimated to be suitable using this model.

Relative abundance and density: Relative abundance data for the four sample sites are presented in Table 1 . In general, there is a little variation across the transect survey sites where titi monkeys were recorded. It is worth mentioning that an examination of the data suggests a fairly localized distribution across wide areas at these survey sites. Overall mean and modal group size was three (mean: SE 0.19). Distance sampling analysis of 902 km of line transect data from the Río Hondo, Río Tuichi, Alto Madidi, and Río Undumo study sites revealed an overall density of 6.2 animals/km² (Hazard Rate Model; n = 33 transect sightings; 95% Confidence Limits: 2.7–14.2 animals/km²). These results combined with the habitat availability model provide a crude population estimate of around 26,400 animals (95% Confidence Limits: 11,491– 60,435 animals).

Figures

Figure 1. Known and hypothetical C. aureipalatii distribution in northern La Paz Department, Bolivia.

Figure 2. The Madidi titi monkey, Callicebus aureipalatii sp. nov. Illustration by Annika Felton.

Figure 3. C. aureipalatii, new species. Views of the male holotype (CBF7511). Photographs by R. B. Wallace.

Figure 4. C. aureipalatii, new species. Views of the male holotype (CBF7511). Photographs by R. B. Wallace.

Figure 5. Details of the adult male holotype C. aureipalatii (CBF7511): a. tail and hind feet, b. hind legs, c. hind foot. Photographs by R. B. Wallace.

Figure 6. Dorsal views of the adult male holotype of C. aureipalatii (CBF7511). Photographs by H. Gómez.

Tables

Table 2. Measurements (in mm) of specimens of C. aureipalatii.

Measurement	Adult male	Adult female
Head and body (mm)	817	800
Tail (mm)	524	480
Hind foot (mm)	102	93
Ear (mm)	36	33
Weight (gm)	1,000	900
Neck circumference (mm)	90	90
Hind leg (mm)	249	247
Fore leg (mm)	207	212
Testicles (mm)	15 × 11 (both)

Table 3. Cranial and dental measurements (mm) of two specimens of C. au- reipalatii following Kobayashi (1995).

Cranial measurements	Adult male	Adult female
Nasion – Rhinion	8.20	10.33
Rhinion – Prosthion	13.43	11.70
Nasion – Prosthion	20.44	22.49
Left maxillofrontale – Right maxillofrontale	3.48
Left frontomalare orbitale – Right frontomalare orbitale	29.08
Left zygomaxillare superior – Right zygomaxillare superior	24.75
Left frontomalare orbitale – Left zygomaxillare superior	13.10	12.52
Left zygomaxillare superior – Left zygomaxillare inferior	13.47	15.06
Greatest width across outer margins of orbit	34.28
Left zygion – Right zygion	39.28
Greatest width across narrowest part in postorbital portion	29.31
Left euryon – Right euryon	33.80	33.71
Prosthion – Bregma	48.32	47.82
Nasion – Bregma	31.49	28.74
Bregma – Lambda	25.76	26.24
Prosthion – Lambda	61.94	62.66
Basion – Bregma	31.37	31.62
Left zygomaxillare inferior – Right zygomaxillare inferior	29.43
Left kondilion laterale – Right kondilion laterale	32.74
Left koronion – Right koronion	33.87
Infradentale – Left kondilion laterale	40.78	41.42
Infradentale – Gnathion	11.79
Greatest length between left koronion and base of mandibular	35.66	36.82
Dental measurements
PM3–M3	16.65	-
I–M3	24.45	-
PM3–M3	16.10	16.40
M1–M3	9.25	8.95
I2–I2	9.80	-
C1–C1	13.60	-
M1–M1	18.35	-
M3–M3	18.55	-