Locomotor behavior and skeletal morphology of two sympatric pitheciine monkeys,Pithecia pithecia and Chiropotes satanas

Field observations of two sympatric pitheciine species reveal that the positional repertoire of the white-faced saki, Pithecia pithecia, is dominated by leaping behaviors, whereas the bearded saki, Chiropotes satanas, is predominantly quadrupedal. Examination and comparison of the postcranial skeletal morphologies and limb proportions of these species display numerous features associated with their respective locomotor behaviors. These observations accord with associations found in other primate and mammalian groups and with predictions based on theoretical and experimental biomechanics. Preliminary observations of the skeletal morphology of Cacajao calvus demonstrate a marked similarity to that of Chiropotes. The fossil platyrrhine Cebupithecia sarmientoi displays greater similarity to Pithecia, suggesting that its positional repertoire also included significant leaping and clinging behaviors.     

Taxonomy and distribution ofPresbytis melalophos group in Sumatera,Indonesia

Taxonomy of thePresbytis melalophos group in Sumatera has been based solely on the distinction in the pelage coloration and has been a subject of controversy. In the present study, extensive field observations were undertaken. Three species, i. e.P. melalophos, P. thomasi, andP. femoralis, are recognized in Sumatera based on the cranial morphology, pelage coloration, and vocalization. Subspecies of each species are revised, a new classification is proposed, and a new subspecies,Presbytis melalophos bicolor, is described. A detailed distribution map of species and subspecies is presented. No sympatry occurs between the species. Finally, a cladistic analysis is presented for the three species, based on the cranial characters; the branching sequence is first between theP. melalophos clade and theP. femoralis- P. thomasi clade and second between theP. femoralis clade and theP. thomasi clade.     

Axial skeleton of Cebupithecia sarmientoi (Pitheciinae,Platyrrhini) from the middle miocene of La Venta,Colombia

The axial skeleton of Cebupithecia sarmientoi is described and analyzed for its functional and phylogenetic implications. The vertebrae of the holotype of C. sarmientoi (UCMP 38762) most closely resemble those of the extant pitheciine genus Pithecia and display features associated with adaptations for clinging and leaping as in that genus. Cebupithecia has a relatively long non-prehensile tail, which is most similar in absolute dimensions and proportions to Pithecia monachus. It also shares with P. monachus a distinctive morphology of the thoracic vertebrae, specifically the presence of a bony pillar spanning the vertebral lamina and body, caudal to the pedicle, herein designated the vinculum laminum. It is proposed that many of these features are shared primitive retentions from the last common ancestor of the Cebupithecia-pitheciine clade.     

Notes on the ecology of buffy saki monkeys (Pithecia albicans,Gray 1860): A canopy seed-predator

Data on the ecology and diet of buffy sakis (Pithecia albicans) were obtained during a 20-month study in an entirely undisturbed terra firme forest in the upper Urucu river, Amazonas, Brazil. Groups of 3–7 sakis found in a 900-ha study plot used large home ranges (147–204 ha), which overlapped extensively with those of neighboring groups. Similar to other pitheciines, buffy sakis were primarily seed predators, relying heavily on young seeds of certain key plant families, such as the Sapotaceae and Leguminosae. Ripe fruits, ripe seeds, young leaves, flowers, and nectar were eaten to a lesser extent. Whether or not feeding, sakis spent most of their time in the canopy and subcanopy, a pattern similar to that of other southwestern Amazonian saki species, but sharply different from that of Guianan sakis (Pithecia pithecia), which use considerably lower levels of the forest. Comparisons are made between different Pithecia species to show whether and how P. albicans diverges ecologically from its congeners. © 1993 Wiley-Liss, Inc.     

A field observation on color selection by New World sympatric primates,Pithecia pithecia and Alouatta seniculus

This work characterizes differences in selection ofTalisia retusa fruits by two sympatric Neotropical primates,Pithecia pithecia (white-faced sakis) andAlouatta seniculus (red howlers). Color appears to be the criterion by which fruits were selected. Greenish fruits were mainly eaten byPithecia, while yellowish fruits byAlouatta. The characteristics of these primates in relation to seed predation and seed dispersal are discussed in the context of theTalisia retusa fruit color spectrum. Furthermore, a possible differential acquisition of chemical components, like tannins, is hypothetically treated considering the variation in fruit color.     

The description of a new species of Myzopoda (Myzopodidae: Chiroptera) from western Madagascar

A new species of Myzopoda (Myzopodidae), an endemic family to Madagascar that was previously considered to be monospecific, is described. This new species, M. schliemanni, occurs in the dry western forests of the island and is notably different in pelage coloration, external measurements and cranial characters from M. aurita, the previously described species, from the humid eastern forests. Aspects of the biogeography of Myzopoda and its apparent close association with the plant Ravenala madagascariensis (Family Strelitziaceae) are discussed in light of possible speciation mechanisms that gave rise to eastern and western species.     

Cranial evolution in sakis (Pithecia, Platyrrhini) I: interspecific differentiation and allometric patterns

Patterns of interspecific differentiation in saki monkey (Pithecia) skulls are quantitatively described. The taxonomic arrangement previously proposed by Hershkovitz ([1987] Am. J. Primatol. 12:387-468) is consistent with quantitative differences in saki morphology. Discriminant analyses on 39 skull traits show that Pithecia species and subspecies are well-differentiated. Morphological distances (D2) among sakis clearly show the morphological unity of the pithecia-chrysocephala (Pithecia) and irrorata-vanzolinii-monacha (Monacha) species groups. The Pithecia species group is distributed north of the Amazon and has a smaller cranium than the Monacha group, distributed south of that river. Despite the size difference, multivariate static allometric patterns among sakis are quite similar. After removing size and allometric changes in shape from the data, species and subspecies are still differentiated, although to a lesser extent. D2 distances obtained from these scale-corrected data are similar in magnitude and pattern to the original D2, but show a closer similarity of P. monacha with the Pithecia group. P. monacha is a scaled-up version of the smaller sakis.     

Uacaries,new world monkeys of the genus Cacajao(Cebidae,Platyrrhini): A preliminary taxonomic review with the description of a new subspecies

The two known species of uacaries, inhabitants of the upper Amazonian region, are the black head Cacajao melanocephalus with subspecies C. m. melanocephalus Humboldt and C. m. ouakary Spix, and the larger bald head uacari C. calvus with subspecies C. c. ucayalii Thomas, C. c. rubicundus I. Geoffroy and Deville, C. c. calvus I. Geoffroy, and C. c. novaesi described as new. The diagnostic generic characters described are the external, cranial, dental, some postcranial, and cytogenetic. The species are described and compared and their geographic distribution plotted with those of their subspecies delimited. Sexual differences are outlined. Apart from size-related characters, the species and subspecies are distinguished by pelage pattern of head and coloration in general. It is shown that both species could have diverged from a hairy-headed melanistic ancestral form. Pelage divergence in the descendants was expressed by the more pilose head of C. melanocephalus, and less pilose of C. calvus. Coloration differentiation was geographic and followed metachromic lines with mutation from eumelanism to partial pheomelanism (reddish or golden) in C. melanocephalus and to virtually complete pheomelanism in C. calvus. The subspecies of each species are distinguished by color patterns resulting from selective bleaching or dilution of the pheomelanin fields. The most saturate pheomelanic subspecies of C. calvus is C. c. ucayalii and the most dilute is the albinotic C. c. calvus. Correlation between coloration and environment is not evident. A gazetteer identifies all locality records plotted by numbers on the geographic distribution maps.     

Biological Basis of Saki (Pithecia) Folk Species Recognized by the Matses Indians of Amazonian Perú

The Matses Indians of northeastern Perú recognize two linguistically labeled folk species of saki monkeys (Cebidae: Pithecia) that are said to be morphologically distinguishable, to prefer different habitats, and to be noninterbreeding. Because the systematic literature recognizes only one biological taxon of Pithecia in the area inhabited by the Matses, their folk taxonomy suggests either the presence of a previously undescribed species or a hitherto undocumented range extension. All known species of Pithecia are currently thought to be allopatric, so both possibilities are of interest. We obtained blood samples and anatomical voucher material from hunters' kills in order to test the biological basis for the Matses folk taxonomy of sakis. Molecular and morphological analyses of the collected material indicate that both Matses folk species correspond to one effectively panmictic population of Pithecia monachus. Overdifferentiation in folk classification systems, whereby one biological species is represented by two or more nonsynonymous folk species names, is a potentially widespread source of error that should be considered by researchers using local informants for primate field studies. In addition to resolving a folk-taxonomic enigma, our study provides the first quantitative analyses of local (within-population) morphological and molecular variation in this little-known platyrrhine genus.     

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.Presented at XIIIth Congress, International Primatological Society, July 27, 1990.     

A phylogenetic study of titi monkeys,genusCallicebus, based on cranial measurements: I. Phyletic groups ofCallicebus

Examinations of 23 forms ofCallicebus were made to elucidate their phylogenetic relationships based on cranial measurements. Multivariate statistical methods of distance analysis utilizing Q-mode correlation coefficients and principal component analysis were employed. As a result, the following five distinct groups were recognized morphometrically among the 23 species and subspecies: theDonacophilus, Cupreus, Moloch, Personatus, andTorquatus groups. Moreover, the phenetic characters of cranial size, karyotype, pelage coloration, and geographic range were consistent with the results of this group classification. It could be safely concluded therefore that these groups represented phylogenetically independent groups, in view of the fact that the rate of character differentiation was not appreciably different among closely related groups. Of the five groups, thePersonatus andTorquatus groups were respectively considered to maintain a higher peculiarity of character differentiation within theCallicebus phylogeny, since these two groups individually displayed the higher magnitudes of differentiation in both their craniometric shape and some phenetic features. Conversely, the other three groups were considered to be closer to each other in theCallicebus phylogeny.     

Terrestrial Activity in Pitheciins (Cacajao,Chiropotes, and Pithecia)

Neotropical monkeys of the genera Cacajao, Chiropotes, and Pithecia (Pitheciidae) are considered to be highly arboreal, spending most of their time feeding and traveling in the upper canopy. Until now, the use of terrestrial substrates has not been analyzed in detail in this group. Here, we review the frequency of terrestrial use among pitheciin taxa to determine the ecological and social conditions that might lead to such behavior. We collated published and unpublished data from 14 taxa in the three genera. Data were gleaned from 53 published studies (including five on multiple pitheciin genera) and personal communications of unpublished data distributed across 31 localities. Terrestrial activity was reported in 61% of Pithecia field studies (11 of 18), in 34% of Chiropotes studies (10 of 29), and 36% of Cacajao studies (4 of 11). Within Pithecia, terrestrial behavior was more frequently reported in smaller species (e.g. P. pithecia) that are vertical clingers and leapers and make extensive use of the understory than in in the larger bodied canopy dwellers of the western Amazon (e.g. P. irrorata). Terrestrial behavior in Pithecia also occurred more frequently and lasted longer than in Cacajao or Chiropotes. An apparent association was found between flooded habitats and terrestrial activity and there is evidence of the development of a “local pattern” of terrestrial use in some populations. Seasonal fruit availability also may stimulate terrestrial behavior. Individuals also descended to the ground when visiting mineral licks, escaping predators, and responding to accidents such as a dropped infant. Overall, the results of this review emphasize that terrestrial use is rare among the pitheciins in general and is usually associated with the exploitation of specific resources or habitat types. Am. J. Primatol. 74:1106‐1127, 2012. © 2012 Wiley Periodicals, Inc.     

Monitoring female reproductive function by measurement of fecal estrogen and progesterone metabolites in the white-faced saki (Pithecia pithecia)

A simple method for extracting and measuring ovarian steroids in feces is applied to the ovarian cycle, pregnancy, parturition, and period of lactational amenorrhea in Pithecia pithecia. Small amounts of wet, unmixed feces were combined with a modified phosphate buffer, shaken, centrifuged, and decanted, and the supernatant was directly measured for estrogen and progesterone metabolites by enzyme immunoassays. Urinary estrogen and progesterone metabolite measurements were compared to paired fecal measurements to determine the degree to which fecal hormone levels detected the same ovarian events as urinary measurements. The correlation coefficients for the relationship between urinary and fecal hormones for individual animals studied (n = 5) were found to be statistically significant in every case except one sexually immature animal. The application of the method presented here demonstrates that simple solubilization and non-radiometric measurement of ovarian steroids excreted in feces reliably reflect reproductive events in Pithecia pithecia. © 1994 Wiley-Liss, Inc.     

<Emphasis Type="Italic">Tarsius wallacei</Emphasis>: A New Tarsier Species from Central Sulawesi Occupies a Discontinuous Range

On the basis of distinguishing characteristics of various genetic markers, pelage color, tail tuft, and vocalizations, we describe a new species of the genus Tarsius Storr 1780. The new taxon Tarsius wallacei sp. nov. occupies a disjunct range in Central Sulawesi, Indonesia. The two isolated populations differ significantly in body size, but are alike in color, tail tuft dimensions, vocalizations, and genetic composition. Morphologically, the new species is similar to other Sulawesi lowland tarsiers. In the field, it can be distinguished from its congeners via a characteristic duet song and its yellow-brown pelage coloration and a copper-colored throat. Genetic analyses prove Y-chromosomal and mitochondrial DNA sequences and also microsatellite allele frequencies to be absolutely diagnostic.     

Taxonomic status of southern South American Conepatus (Carnivora: Mephitidae)

Despite recent taxonomic evaluations of Mephitidae and North American hog‐nosed skunks, southern South American species of Conepatus have not been thoroughly examined in a systematic context. Conepatus chinga and Conepatus humboldtii were described more than 150 years ago, based on external characters such as hair coloration and size. Although historically recognized as valid species, to date no detailed systematic analysis has been performed for either of these taxa. Herein, we evaluated the taxonomic status of C. chinga and C. humboldtii within the southern part of South America using geometric morphometrics of the skull and mandible, mitochondrial DNA analysis using the cytochrome b and cytochrome oxidase c subunit I genes, and also control region and pelage pattern variation. We failed to find morphological (skull shape and pelage coloration patterns) or molecular differences between these two species; thus, we considered that the specimens assigned to C. chinga and C. humboldtii belong to the same species. Our results indicate that environmental variation seems to be responsible for shape and size variation in Conepatus skulls from southern South America. © 2013 The Linnean Society of London     

Potamotrygon marquesi,a new species of neotropical freshwater stingray (Potamotrygonidae) from the Brazilian Amazon Basin

Potamotrygon marquesi, sp. nov., is described and compared with other species of Potamotrygon occurring in the Amazon Basin. The identity of this new species is supported by an extensive external and internal morphological study including coloration pattern, squamation, skeleton and ventral lateral-line canals. Morphometrics and meristics were used to further distinguish P. marquesi from congeners. Potamotrygon marquesi was first considered to fall within the range of variation found in P. motoro. However, even with an extensive variation in coloration observed in P. motoro, this new species presents a series of autapomorphies that confidently distinguishes it from what is understood as the morphological variation found in P. motoro. Additional morphological characters that diagnose P. marquesi include three angular cartilages, asymmetrical star-shaped denticles, a single regular row of spines on tail dorsum, lateral row of caudal spines near the sting insertion, dorsal disc background in beige and grey mixed with shades of grey and bearing open and closed bicolored rings, among others. Although presenting a gap of distribution along the west–east extension of the Amazon Basin, its diagnostic charactistics are consistent in both recorded regions. Our study supports the need for many morphological characters to robustly distinguish members of Potamotrygoninae considering their extremely variable dorsal disc color pattern.     

Geographic distribution and demography of Pithecia aequatorialis (pitheciidae) in Peruvian Amazonia

To study the geographic distribution and demographic characteristics of Pithecia aequatorialis in Peruvian Amazonia, we undertook surveys and transect census in three river basins (Río Itaya, Río Tigre and Río Curaray) between 2004 and 2008. A total of 123 groups of P. aequatorialis was encountered during 1623 km of transect walks. Group size was uniform among the three areas (3.4–3.6 individuals), but surprisingly, population densities were higher in the area with strong hunting pressure (Río Itaya: 7.8 ind./km², vs. 5.6 and 5.9 km² in the Río Tigre and Río Curaray basins, respectively). The most common group composition included an adult pair with one offspring. Groups with more than one adult male and/or female accounted for 35% of sightings. Our observations extend P. aequatorialis range in Peru further south to the area between the Río Tigre and Río Corrientes, but exclude the area to the north between the Río Curaray and Río Napo. These findings are in contrast to previous distribution maps. P. aequatorialis was rarely seen in interspecific association during our censuses. Am. J. Primatol. 71:964–968, 2009. © 2009 Wiley‐Liss, Inc.     

Notes on the geographic distribution of howling monkeys in the marajó archipelago, pará, Brazil

I review the distribution of genus Alouattain the Marajó Archipelago based on geographic variation of pelage color patterns. Specific differences exist among the labeled specimens at Museu Paraense Emílio Goeldi, which are confirmed via new field information from wild populations. The animals from Marajó, Caviana, and Mexiana Islands possess color patterns of Alouatta belzebul,while Alouatta seniculusis confirmed as the species that inhabits Gurupá Island. The high variability of pelage coloration of the animals from Marajó, Caviana, and Mexiana Islands includes all phenotypes formerly designated as different subspecies. The howler populations from these three islands belong to the same subspecies as those populations that inhabit the region of Tucurui dam reservoir (area 4). Finally, it seems that, as also suggested by chromosome studies, A. belzebulprobably comprises different epiphenotypes without taxonomic validity.