Warren G. Kinzey

Physical and chemical properties of fruit and seeds eaten byPithecia andChiropotes in Surinam and Venezuela

Pithecia pithecia andChiropotes satanas are seed predators that eat fruits with hard pericarps. We measured resistance to puncturing and crushing of fruit and seeds eaten by these two pitheciins at two localities: in evergreen rain forest at Raleighvallen-Voltzberg, Surinam, and in tropical dry/transitional moist forest on islands in Guri Lake, Venezuela. Average measurements of pericarp hardness were similar at both sites for fruit eaten byChiropotes, but a higher maximum value was obtained at the rainforest site.Chiropotes andPithecia both ate fruits that had harder pericarps than did fruits eaten byAteles paniscus, but crushing resistances of seeds eaten were lower than values forAteles. Thus, both pitheciins selected fruits with hard pericarps and soft seeds, although there were notable intergeneric differences in hardness of fruit ingested. When fruit became scarce,Pithecia ate more flowers, whileChiropotes continued to eat fruits with hard seed coverings. Chemical analysis of species of seeds eaten byPithecia suggests that they avoided seeds with extremely high tannin levels, though they tolerated moderate tannin levels in combination with high levels of lipids. We propose that sclerocarpic harvesting (the preparation and ingestion of fruit with a hard pericarp) allows pitheciin monkeys to obtain nutritious seeds, with reduced tannins, that are softer than those ingested by other frugivores.

Ceboid models for the evolution of hominoid dentition

Abstract Platyrrhine and catarrhine Primates have independently evolved such features of the teeth and jaws as U-shaped dental arches, reduced cingula on molars and premolars, and modifications for small tough-object feeding. The presence of specialization for tough-object feeding in arboreal cebids such as Cebus apella and Callicebus indicates that hominids may have acquired such a specialization in an arboreal habitat before becoming terrestrial.

The Dentition of the Pygmy Chimpanzee, Pan paniscus

Prior to 1974 the only studies on the dentition of Pan paniscus involved very small samples. Remane (1960) presented measurements of teeth of 4–11 adult individuals and later (1962) measurements of deciduous teeth of two maxillas and 3–4 mandibles. Conroy (1972) published indices based on measurements of maxillary teeth in three specimens of Pan paniscus to show that relative reduction of incisors and canine of Ramapithecus (FT 1271–2) was greater than that in either species of chimpanzee. Vandebroek (1969) used Pan paniscus extensively to compare with other primates in his book on vertebrate evolution. He included several photos of teeth of P. paniscus: one a lingual view of a deciduous dentition (Vandebroek, 1969, p. 289), and lateral views of male and female permanent dentitions (pp. 388–389). He also presented a graph of average measurements of the three lower molars compared with those of other hominoids (p. 394), and a drawing of lingual views of the lower teeth showing morphological variation (p. 415). Almquist (1974) measured incisors and canines in 18 female and 14 male P. paniscus from Tervuren, and compared these measurements with other African pongids and cercopithecids. He found significant sexual dimorphism in the length, breadth, and height of both upper and lower permanent canines of P. paniscus.

Seed Predation by Monkeys and Macaws in Eastern Venezuela : Preliminary Findings

Feeding data collected concurrently on bearded sakis (Chiropotes satanas) and red and green macaws (Ara chloroptera) on a large island in Guri, Venezuela provides preliminary evidence that these two seed predators have similar diets. Individuals of both species were equally capable of opening very hard, protected fruits. Of the seven fruit species used by macaws during the study period, four species were also ingested by sakis at the same stage of ripeness, two species were ingested at different stages of ripeness (macaws earlier than sakis), and one species was never observed to have been eaten by sakis. The second finding, that macaws ingest young seeds of the Anacardiaceae and Burseraceae families and the bearded sakis ingest only the ripe mesocarp of these species suggests that the most distinguishable difference in their diets might be a tolerance of toxins by the macaws that act as feeding deterrents for the monkeys. Although we did not document the location of local clay licks in eastern Venezuela, the use of clay licks by macaws in Peru (Munn, 1992) suggests that this activity (that is not practiced by the sakis) may be helpful in detoxifying or ameliorating the effects of ingesting chemically protected fruit.

Neotropical primate conservation

Abstract The greatest threat to Neotropical primates is the loss of tropical forest for agriculture, ranching, commercial logging and hydroelectric projects. Hunting of primates for consumption or sale and live capture for the pet trade and for biomedical purposes is also a threat to certain species. Twenty-eight of the 76 Neotropical primate species are considered endangered and the highest density of endangered taxa occurs in Brazils Atlantic forest, followed by Amazonia and Middle America. The most endangered Neotropical primate genera are Brachyteles and Leontopithecus , followed by some species of Ateles, Lagothrix, Saguinus and the Central American squirrel monkey ( Saimiri oerstedii citrinellus ). Solutions to the problems of primate conservation are discussed, including habitat conservation, protection against poaching and international primate trade, education, research and captive propagation, and examples of successful conservation efferts are provided.

Canine teeth of the monkey,Callicebus moloch: Lack of sexual dimorphism

Unlike other primates, the South American titi monkey,Callicebus moloch, does not exhibit sex-differences in the size or shape of the canine teeth, or in the extent of loss or fracture from excessive use. Males and females have similar canines as well in each of six subspecies ofC. moloch. The lack of dimorphism is related to the low level of aggression in this species.