Cebus albifrons (Humboldt, 1812)

Voss, Robert S. & Fleck, David W., 2011, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 1: Primates, Bulletin of the American Museum of Natural History 2011 (351), pp. 1-81 : 35-36

Cebus albifrons (Humboldt, 1812)

VOUCHER MATERIAL (TOTAL 5 7): Boca Río Yaquerana (FMNH 88854, 88855, 89173); Nuevo San Juan (MUSM 11119); Orosa (AMNH 73723, 74034); Santa Cecilia (FMNH 86932).

UNVOUCHERED OBSERVATIONS: Actiamë ( Amanzo, 2006), Choncó ( Amanzo, 2006), Divisor ( Jorge and Velazco, 2006), Jenaro Herrera ( Aquino, 1978), Orosa ( Freese et al., 1982), Reserva Comunal Tamshiyacu-Tahuayo ( Puertas and Bodmer, 1993; Heymann and Aquino, 1994), Río Tapiche ( Bennett et al., 2001), Río Yavarí (left bank below Angamos; Salovaara et al., 2003), Río Yavarí-Mirím ( Salovaara et al., 2003).

IDENTIFICATION: The last morphological revision of Cebus was by Hill (1960), who reviewed the tediously complex and unedifying nomenclatural history of this difficult genus. Most students of capuchin taxonomy (e.g., Elliot, 1913; Hershkovitz, 1949; Hill, 1960) have emphasized the distinction between ‘‘tufted’’ and ‘‘untufted’’ species based on the presence or absence of tufts or crests of coronal fur in adult males (additional characters diagnosing these groups were tabulated by Hershkovitz, 1949). As far as known, no local fauna anywhere in the Neotropics has more than one species of tufted capuchin or more than one untufted species, whereas tufted and untufted capuchins occur sympatrically throughout much of Amazonia. Thus, the distinction seems important, and Silva (2002) recently proposed that these groups be formally recognized as subgenera: Cebus Erxleben, 1777 , for the untufted species; and Sapajus Kerr, 1792, for the tufted species. At least some genetic evidence suggests that these might, in fact, be reciprocally monophyletic taxa ( Casado et al., 2010).

The untufted capuchin of western Amazonia, Cebus albifrons , has been divided into a number of subspecies by authors. Based on mapped geographic ranges in Hershkovitz (1949) and Hill (1960), the population inhabiting the Yavarí-Ucayali interfluve is assign- able to C. a. unicolor (Spix, 1823), the type locality of which is Tefé (on the south bank of the Amazon between the Juruá and the Purus), Amazonas, Brazil. However, Defler and Hernández-Camacho (2002) argued that Spix’s unicolor is phenotypically indistinguishable from the nominotypical race, the type locality of which (fixed by neotype selection) is ‘‘about 10 km north of Maypures … Vichada, Colombia’’ (op. cit.: 54). Our voucher material is somewhat darker and duller than the color illustration of the neotype of C. a. albifrons (in Defler and Hernández-Camacho, 2002), but we remain unconvinced of the need for trinomial nomenclature to distinguish minor pelage differences among Amazonian populations of this species. Measurements of specimens collected in the Yavarí-Ucayali interfluve ( table 10 ) are slightly larger than most homologous dimensions of topotypical C. a. albifrons (in Defler and Hernández-Camacho, 2002), but sample sizes are too small for confident inference.

MATSES NATURAL HISTORY: White-front- ed capuchin monkeys are light-colored, except for the tops of their heads, which are brown. Their backs and tails are darker than their faces, chests, and bellies. Like brown capuchin monkeys, white-fronted capuchin monkeys raise their eyebrows repeatedly when they see people. Males touch their penises when they see people.

White-fronted capuchin monkeys can be found in any habitat, but they are more common in upland forest than in riverside forest, whereas brown capuchin monkeys have the opposite preference. They sometimes come to the edge of swiddens. Whitefronted capuchin monkeys spend more time foraging on the ground than any other type of monkey. They play on the ground in small clearings. They use mostly the lower canopy, but go high to feed when they find food up high.

Troops are medium-sized, numbering up to about 20 or 25 animals, though more frequently about 8 to10. They have many young in their troops, which scream a lot as they pass from tree to tree. Sometimes whitefronted capuchin monkeys travel with woolly monkeys, but never with squirrel monkeys. They are less commonly encountered than brown capuchin monkeys.

They call differently from brown capuchin monkeys, calling: ‘‘ kooo kooo kooo,’’ among other vocalizations. Like brown capuchin monkeys, they break off dead branches and palm fronds and pull off wasp nests and throw them down. They sleep together in a group up in a tree, unlike woolly monkeys, which spread out in different trees.

Their food is the same as that of brown capuchin monkeys [see below; however, unlike brown capuchins, they have not been observed to kill and eat titi monkeys]. They have the same ability to break open hard dicot fruits and palm nuts.

Tables

TABLE 10 External and Craniodental Measurements (mm) of Cebus albifrons from the Yavarí-Ucayali Interfluve

	FMNH	FMNH	AMNH	FMNH
	869323	888543	73723♀	88855♀
HBL	400	440	—	371
LT	460	470	—	444
HF	130	143	—	139
Ear	35	37	—	36
CIL	74.7	82.1	69.1	70.6
OB	57.2	59.0	55.7	54.0
POC	40.2	42.7	40.6	42.7
ZB	63.8	71.7	62.3	60.4
BB	53.3	55.2	51.8	53.3
PPL	32.2	35.4	—	29.5
LMT	27.7	29.2	25.6	27.7
BM1	5.5	5.8	5.2	5.5
M1–M1	28.4	30.6	28.6	30.7
I2–I2	14.6	15.7	13.0	14.8