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Thomas R. Defler - One of the best experts on this subject based on the ideXlab platform.
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Phylogenetic relationships within the Callicebus cupreus species group (Pitheciidae: Primates): Biogeographic and taxonomic implications.
Molecular Phylogenetics and Evolution, 2016Co-Authors: Manuel Hoyos, Fabio Rohe, Jan Vermeer, Paul Bloor, Thomas R. Defler, Izeni Pires FariasAbstract:The genus Callicebus (Thomas, 1903) is one of the most diverse of Neotropical primate genera and the only extant member of the Callicebinae subfamily. It has a widespread distribution from Colombia to Brazil, Bolivia, Peru and northern Paraguay. Coat colouring and colour pattern vary substantially within the genus, and this has led to the description of numerous species and subspecies, as well as numerous species groups. However, a lack of molecular phylogenetic analyses on the genus means that phylogenetic relationships and biogeographic history of species are poorly understood. Here, we examined phylogenetic relationships and patterns of diversification within the Callicebus cupreus species Group (sensu Kobayashi, 1995) using complete mitochondrial DNA cytochrome b gene sequence. Analyses indicate that the Callicebus cupreus Group underwent recent and extensive diversification. The common ancestor appears to have emerged some 2.3 million years ago (Ma) from a centre of origin in the western Amazon region, followed by diversification of the group between about 1.5 and 1.2Ma. Phylogenetic analyses were able to recover most previously described species (including the recently described Colombian endemic Callicebus caquetensis). However, there are some notable inconsistences between the obtained phylogeny and current taxonomy. Some previously recognized taxa were not separated by our data (e.g., Callicebus caligatus and Callicebus dubius), while currently unrecognized species diversity was uncovered within C. cupreus in the form of two divergent lineages: one of which exhibited greater phylogenetic similarity to species from the C. moloch Group. Based on the present study, we challenge current taxonomic arrangements for the C. cupreus species Group and call for a thorough taxonomic revision within the genus Callicebus.
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Aportes citogenéticos en el esclarecimiento de la taxonomía del género Callicebus
2010Co-Authors: Marta Lucía Bueno, Thomas R. DeflerAbstract:The Callicebus are small primates (800-1,200 g) amply distributed in South America. The taxonomy of the genus has been discussed by various authors. Recently Defler (2004), based on work by Hershkovitz (1990) recognized two groups of species in Colombia: Callicebus cupreus and Callicebus torquatus. Because of high karyotypic variability in the genus, karyotypes constitute an important systematic character. Wide differences in chromosome number are well-correlated with species groups that have been described for the genus based on morphological and biogeographical characteristics. Characteristic of the species in the cupreus group are high chromosome numbers (2n=44 for C. c. ornatus and 2n=46 for C. c. discolor and C. c. caquetensis). In contrast, the C. torquatus species group has low chromosome numbers (2n=16 for C. lugens and 2n=20 for Callicebus torquatus and C. t. lucifer and possibly C. t. medemiwhich has not yet been studied genetically). Based on our cytogenetic finds from cell cultures from 11 specimens from different populations of Callicebus, we have found that our karyological data are concordant with the species groups and permit us to differentiate C. ornatus, C. caquetensis and C. discolor as independent species in the cupreus group. In the torquatus group there were no detectable differences between a "lugens" phenotype from Florencia, Caqueta and a C. t. lucifer from the Colombian trapezium (both were 2n=20), increasing the distribution of the species with that karyotype in the Colombian Amazon. Although initially we supposed that C. lugens (2n=16) was not present in the Colombian Amazon, the discovery of a C. lugens (2n=16) in the Matacana Zoo strongly suggests the presence of this species in the Colombian Orinoco, although this must be confirmed with field studies. Based on our results a discussion of the evolutionary process in chromosomes is presented for this monogamous, territorial primate genus and some hypotheses regarding the evolution of this group are proposed.
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Callicebus caquetensis: A New and Critically Endangered Titi Monkey from Southern Caquetá, Colombia
Primate Conservation, 2010Co-Authors: Thomas R. Defler, Marta Lucía Bueno, Javier GarciaAbstract:Abstract: We describe a new species of titi monkey Callicebus (Primates: Platyrrhini) from the Department of Caqueta, Colombia, that belongs to the Callicebus cupreus group. Diagnostic characteristics: it is similar in fur color to C. ornatus and C. discolor, but has no white band on the forehead as in C. ornatus and C. discolor, and the hands and feet are not white as they are in C. ornatus. The karyotype of this species is 2n=46, and very similar to that published for C. cupreus. Comparing it to neighboring species, it is more similar cytologically to C. discolor than to C. ornatus. It should be classified as Critically Endangered (CR) due to the severe fragmentation of its habitat and very small population.
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The Conservation Status of Callicebus caquetensis (Pitheciidae): A New Species in Southern Caquetá Department, Colombia
Neotropical Primates, 2010Co-Authors: Javier Garcia, Thomas R. Defler, Marta Lucía BuenoAbstract:Abstract Moynihan (1976) mentioned an undescribed species of Callicebus between the rios Caqueta and Orteguaza, Caqueta Department, Colombia. In August 2008, we confirmed the new species, which is phylogenetically related to C. ornatus and C. discolor to the north and south of the type locality respectively. We described this species as Callicebus caquetensis Defler et al., 2010 establishing its distribution through direct observations and information from local communities. Eighty-two animals were seen, including the holotype and paratype, which were collected. A review of historical archives of aerial photographs and satellite maps was carried out to assess the loss of the original vegetation of the area, and we found the habitat in an advanced state of fragmentation caused by extensive ranching and illegal crop cultivation. Existing coverage is now limited to small fragments of the original primary forest and secondary vegetation. We analyzed a Google Earth image of 75 km2 of this primate's habitat and...
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Callicebus torquatus is not a white‐sand specialist
American journal of primatology, 1994Co-Authors: Thomas R. DeflerAbstract:The hypothesis of Kinzey and Gentry [Primate Ecology: Problem Oriented Field Studies. New York, John Wiley & Sons, 1979] that Callicebus torquatus may be specialized for living in vegetation on white sand was evaluated by reviewing all observations I made of this species, where the substrate had been noted, and including some collection sites of J. Hernandez Camacho. There was no evidence for the white-sand hypothesis. Instead, Callicebus torquatus was found to prefer upland and flooded forests that are tall and well stratified, and growing on many soil types, including white sand. © 1994 Wiley-Liss, Inc.
Jan Vermeer - One of the best experts on this subject based on the ideXlab platform.
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Phylogenetic relationships within the Callicebus cupreus species group (Pitheciidae: Primates): Biogeographic and taxonomic implications.
Molecular Phylogenetics and Evolution, 2016Co-Authors: Manuel Hoyos, Fabio Rohe, Jan Vermeer, Paul Bloor, Thomas R. Defler, Izeni Pires FariasAbstract:The genus Callicebus (Thomas, 1903) is one of the most diverse of Neotropical primate genera and the only extant member of the Callicebinae subfamily. It has a widespread distribution from Colombia to Brazil, Bolivia, Peru and northern Paraguay. Coat colouring and colour pattern vary substantially within the genus, and this has led to the description of numerous species and subspecies, as well as numerous species groups. However, a lack of molecular phylogenetic analyses on the genus means that phylogenetic relationships and biogeographic history of species are poorly understood. Here, we examined phylogenetic relationships and patterns of diversification within the Callicebus cupreus species Group (sensu Kobayashi, 1995) using complete mitochondrial DNA cytochrome b gene sequence. Analyses indicate that the Callicebus cupreus Group underwent recent and extensive diversification. The common ancestor appears to have emerged some 2.3 million years ago (Ma) from a centre of origin in the western Amazon region, followed by diversification of the group between about 1.5 and 1.2Ma. Phylogenetic analyses were able to recover most previously described species (including the recently described Colombian endemic Callicebus caquetensis). However, there are some notable inconsistences between the obtained phylogeny and current taxonomy. Some previously recognized taxa were not separated by our data (e.g., Callicebus caligatus and Callicebus dubius), while currently unrecognized species diversity was uncovered within C. cupreus in the form of two divergent lineages: one of which exhibited greater phylogenetic similarity to species from the C. moloch Group. Based on the present study, we challenge current taxonomic arrangements for the C. cupreus species Group and call for a thorough taxonomic revision within the genus Callicebus.
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The Distribution and Taxonomy of Titi Monkeys (Callicebus) in Central and Southern Peru, with the Description of a New Species
Primate Conservation, 2015Co-Authors: Jan Vermeer, Julio C. Tello-alvaradoAbstract:Abstract: Here we report on the results of a study on the distribution and taxonomy of titi monkeys, genus Callicebus, in the central part of Peru. We reinstate Callicebus toppini Thomas, a species described in 1914, but since then neglected by science. It evidently has a wide distribution in southern Peru, western Brazil and northern Bolivia. Based on field observations, analysis of museum specimens, and photographs, we also describe a new species of Callicebus from the Rio Urubamba basin, endemic to Peru. Reliable identification of titi monkeys observed in the wild is crucial to avoid confusion and to determine conservation strategies.
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GIS Risk Assessment and GAP Analysis for the Andean Titi Monkey (Callicebus oenanthe)
Primate Conservation, 2013Co-Authors: Sam Shanee, Jan Vermeer, Julio C. Tello-alvarado, Antonio J. Bóveda-penalbaAbstract:Abstract: We conducted a predictive GIS (Geographical Information System) analysis to create a realistic Habitat Suitability Model (HSM) and risk analysis throughout the distribution of the Andean titi monkey (Callicebus oenanthe) in order to evaluate the effectiveness of the current protected area (PA) network. This was done to help current conservation work and aid in the planning and implementation of future initiatives. Little was known about this species until recently. Callicebus oenanthe is listed as Critically Endangered on the IUCN Red List of Threatened Species. It is endemic to San Martin region, northeastern Peru. Our results show that the extent of habitat available for this species may be greater than previously thought but that habitat loss in the region is extremely high. GAP analysis indicates that the current protected area network is ineffective in protecting this species, and new reserve areas are urgently needed. We recommend further study into the species' ecology to better understan...
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extension of the geographical range of white browed titi monkeys Callicebus discolor and evidence for sympatry with san martin titi monkeys Callicebus oenanthe
International Journal of Primatology, 2011Co-Authors: Jan Vermeer, Julio C Telloalvarado, Sergio Morenomoreno, Fernando GuerravasquezAbstract:White-browed titi monkeys (Callicebus discolor) have one of the largest distribution ranges of all titi monkey species, occurring from central Peru to southern Colombia. During a long-term study on the distribution of titi monkeys and other primates in Peru, we conducted extensive surveys in the San Martin Department of northeastern Peru. We encountered Callicebus discolor at the left bank of the Huallaga River, where the species most probably lives in sympatry with endemic San Martin titi monkeys (Callicebus oenanthe). Our study reveals an important extension of its formerly known distribution range. Massive deforestation activities in the region make studies on the habitat preferences of both species difficult, as most titi monkeys are confined to the remaining small remnants of the original forest. Urgent conservation measures are necessary to preserve the last lowland forests of San Martin.
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Preliminary Report on the Distribution of Callicebus oenanthe on the Eastern Feet of the Andes
International Journal of Primatology, 2009Co-Authors: Antonio J. Bóveda-penalba, Jan Vermeer, Fernando Rodrigo, Fernando Guerra-vásquezAbstract:In 2007 we conducted a field study of almost 6 mo to determine the distribution of Callicebus oenanthe , formerly known as the Andean titi monkey. There previously has been no extensive study on the distribution and status by other fieldworkers. We visited a total of 96 localities within or around the presumed distribution of this rare primate species to determine the distribution of Callicebus oenanthe . We collected additional information on group size and threats to the species. Our expeditions revealed that the species is not endemic to the Alto Mayo Valley, as earlier authors suggested, but that its distribution extends into the Bajo Mayo and Huallaga Central. The study area is heavily deforested, and to date only one area was found where a viable population might live, although further research is needed to confirm this. The species lives in the southern part of its distribution in sympatry with another, undescribed species of Callicebus. We will continue the study to determine more precisely the distribution and conservation status of the Callicebus oenanthe , to determine if conservation measures are necessary for this species. This is the first activity of a long-term project for the conservation of Callicebus oenanthe initiated by La Vallée des Singes Primate park.
Izeni Pires Farias - One of the best experts on this subject based on the ideXlab platform.
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Phylogeny, molecular dating and zoogeographic history of the titi monkeys (Callicebus, Pitheciidae) of eastern Brazil.
Molecular Phylogenetics and Evolution, 2018Co-Authors: Jeferson Carneiro, Iracilda Sampaio, José De Sousa E Silva-júnior, Izeni Pires Farias, Tomas Hrbek, Jean P. Boubli, Alcides Pissinatti, Ronylson J S Silva, Antonio Marcio Gomes Martins-junior, Stephen F. FerrariAbstract:The titi monkeys belong to a genus of New World primates endemic to South America, which were recently reclassified in three genera (Cheracebus, Plecturocebus and Callicebus). The genus Callicebus, which currently includes five species, is endemic to eastern Brazil, occurring in the Caatinga, Savanna, and Atlantic Forest biomes. In the present study, we investigated the validity of these species and inferred their phylogenetic relationships, divergence times, and biogeographic patterns based on the molecular analysis of a concatenated sequence of 11 mitochondrial and nuclear DNA markers, derived from 13 specimens. We ran Maximum Likelihood (ML) and Bayesian Inference (BI) analyses, and estimated genetic distances, divergence times. Ancestral areas were estimated on BioGeoBears. Our results suggest that at about twelve million years ago, the ancestor of all titi monkeys inhabited a wide area that extended from the Amazon forest to the South of the Atlantic forest. A first vicariant event originated Cheracebus in the West of the Amazon and the ancestor of Callicebus and Plectorocebus which, later were separated by a second one. The diversification of Callicebus occurred during the Plio-Pleistocene (beginning at 5 Ma) probably influenced by climatic fluctuations and geological events. Therefore, the results of the present work confirmed the existence of five species that currently inhabit forested areas under increasing threat from human activities. Thus, a reliable diagnosis of the taxonomic status of species living in endangered environments is extremely important for the development of conservation measures.
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phylogenetic relationships of the new world titi monkeys Callicebus first appraisal of taxonomy based on molecular evidence
Frontiers in Zoology, 2016Co-Authors: Hazel Byrne, Jeferson Carneiro, Mariluce Rezende Messias, Anthony B. Rylands, Fabricio Bertuol, Maria N. F. Da Silva, Colin P. Groves, Russell A. Mittermeier, Jessica Lynch Alfaro, Izeni Pires FariasAbstract:Titi monkeys, Callicebus, comprise the most species-rich primate genus—34 species are currently recognised, five of them described since 2005. The lack of molecular data for titi monkeys has meant that little is known of their phylogenetic relationships and divergence times. To clarify their evolutionary history, we assembled a large molecular dataset by sequencing 20 nuclear and two mitochondrial loci for 15 species, including representatives from all recognised species groups. Phylogenetic relationships were inferred using concatenated maximum likelihood and Bayesian analyses, allowing us to evaluate the current taxonomic hypothesis for the genus. Our results show four distinct Callicebus clades, for the most part concordant with the currently recognised morphological species-groups—the torquatus group, the personatus group, the donacophilus group, and the moloch group. The cupreus and moloch groups are not monophyletic, and all species of the formerly recognized cupreus group are reassigned to the moloch group. Two of the major divergence events are dated to the Miocene. The torquatus group, the oldest radiation, diverged c. 11 Ma; and the Atlantic forest personatus group split from the ancestor of all donacophilus and moloch species at 9–8 Ma. There is little molecular evidence for the separation of Callicebus caligatus and C. dubius, and we suggest that C. dubius should be considered a junior synonym of a polymorphic C. caligatus. Considering molecular, morphological and biogeographic evidence, we propose a new genus level taxonomy for titi monkeys: Cheracebus n. gen. in the Orinoco, Negro and upper Amazon basins (torquatus group), Callicebus Thomas, 1903, in the Atlantic Forest (personatus group), and Plecturocebus n. gen. in the Amazon basin and Chaco region (donacophilus and moloch groups).
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Phylogenetic relationships within the Callicebus cupreus species group (Pitheciidae: Primates): Biogeographic and taxonomic implications.
Molecular Phylogenetics and Evolution, 2016Co-Authors: Manuel Hoyos, Fabio Rohe, Jan Vermeer, Paul Bloor, Thomas R. Defler, Izeni Pires FariasAbstract:The genus Callicebus (Thomas, 1903) is one of the most diverse of Neotropical primate genera and the only extant member of the Callicebinae subfamily. It has a widespread distribution from Colombia to Brazil, Bolivia, Peru and northern Paraguay. Coat colouring and colour pattern vary substantially within the genus, and this has led to the description of numerous species and subspecies, as well as numerous species groups. However, a lack of molecular phylogenetic analyses on the genus means that phylogenetic relationships and biogeographic history of species are poorly understood. Here, we examined phylogenetic relationships and patterns of diversification within the Callicebus cupreus species Group (sensu Kobayashi, 1995) using complete mitochondrial DNA cytochrome b gene sequence. Analyses indicate that the Callicebus cupreus Group underwent recent and extensive diversification. The common ancestor appears to have emerged some 2.3 million years ago (Ma) from a centre of origin in the western Amazon region, followed by diversification of the group between about 1.5 and 1.2Ma. Phylogenetic analyses were able to recover most previously described species (including the recently described Colombian endemic Callicebus caquetensis). However, there are some notable inconsistences between the obtained phylogeny and current taxonomy. Some previously recognized taxa were not separated by our data (e.g., Callicebus caligatus and Callicebus dubius), while currently unrecognized species diversity was uncovered within C. cupreus in the form of two divergent lineages: one of which exhibited greater phylogenetic similarity to species from the C. moloch Group. Based on the present study, we challenge current taxonomic arrangements for the C. cupreus species Group and call for a thorough taxonomic revision within the genus Callicebus.
Gerald H. Jacobs - One of the best experts on this subject based on the ideXlab platform.
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Color Vision Variation and Foraging Behavior in Wild Neotropical Titi Monkeys (Callicebus brunneus): Possible Mediating Roles for Spatial Memory and Reproductive Status
International Journal of Primatology, 2011Co-Authors: John A. Bunce, Lynne A. Isbell, Mark N. Grote, Gerald H. JacobsAbstract:The selective advantages to primates of trichromatic color vision, allowing discrimination among the colors green, yellow, orange, and red, remain poorly understood. We test the hypothesis that, for primates, an advantage of trichromacy over dichromacy, in which such colors are apt to be confused, lies in the detection of yellow, orange, or red (YOR) food patches at a distance, while controlling for the potentially confounding influences of reproductive status and memory of food patch locations. We employ socially monogamous titi monkeys ( Callicebus brunneus ) which, like most platyrrhine primates, have polymorphic color vision resulting in populations containing both dichromatic and trichromatic individuals. Wild Callicebus brunneus spent most foraging time in YOR food patches, the locations of most of which were likely to have been memorable for the subjects. Overall, both dichromatic and trichromatic females had significantly higher encounter rates than their dichromatic male pair mates for low-yield ephemeral YOR food patches whose locations were less likely to have been remembered. We detected no difference in the encounter rates of dichromatic and trichromatic females for such patches. However, the data suggest that such a difference may be detectable with a larger sample of groups of Callicebus brunneus , a larger sample of foraging observations per group, or both. We propose that a trichromatic advantage for foraging primates may be realized only when individuals’ energy requirements warrant searching for nonmemorable YOR food patches, a context for selection considerably more limited than is often assumed in explanations of the evolution of primate color vision.
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RESEARCH ARTICLE Characterization of Opsin Gene Alleles Affecting Color Vision in a Wild Population of Titi Monkeys (Callicebus brunneus)
2011Co-Authors: John Andrew Bunce, Gerald H. Jacobs, Lynne A. Isbell, Maureen Neitz, Daniela Maria Oliveira Bonci, Alison K. Surridge, David GlennAbstract:The color vision of most platyrrhine primates is determined by alleles at the polymorphic X-linked locus coding for the opsin responsible for the middle- to long-wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunneus (the brown titi monkey), a primate that an earlier study suggests may possess an unusual number of alleles at this locus and thus may be a subject of special interest in the study of primate color vision. Direct sequencing of regions of the M/L opsin gene using feces-, blood-, and saliva-derived DNA obtained from 14 individuals yielded evidence for the presence of three functionally distinct alleles, corresponding to the most common M/L photopigment variants inferred from a physiological study of cone spectral sensitivity in captive Callicebus. Am. J. Primatol. 73:189–196, 2011. r 2010 Wiley-Liss, Inc.
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Characterization of opsin gene alleles affecting color vision in a wild population of titi monkeys (Callicebus brunneus)
American journal of primatology, 2010Co-Authors: John Andrew Bunce, Gerald H. Jacobs, Lynne A. Isbell, Maureen Neitz, Daniela Maria Oliveira Bonci, Alison K. Surridge, David Glenn SmithAbstract:The color vision of most platyrrhine primates is determined by alleles at the polymorphic X-linked locus coding for the opsin responsible for the middle- to long-wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunneus (the brown titi monkey), a primate that an earlier study suggests may possess an unusual number of alleles at this locus and thus may be a subject of special interest in the study of primate color vision. Direct sequencing of regions of the M/L opsin gene using feces-, blood-, and saliva-derived DNA obtained from 14 individuals yielded evidence for the presence of three functionally distinct alleles, corresponding to the most common M/L photopigment variants inferred from a physiological study of cone spectral sensitivity in captive Callicebus. Am. J.
Stephen F. Ferrari - One of the best experts on this subject based on the ideXlab platform.
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Phylogeny, molecular dating and zoogeographic history of the titi monkeys (Callicebus, Pitheciidae) of eastern Brazil.
Molecular Phylogenetics and Evolution, 2018Co-Authors: Jeferson Carneiro, Iracilda Sampaio, José De Sousa E Silva-júnior, Izeni Pires Farias, Tomas Hrbek, Jean P. Boubli, Alcides Pissinatti, Ronylson J S Silva, Antonio Marcio Gomes Martins-junior, Stephen F. FerrariAbstract:The titi monkeys belong to a genus of New World primates endemic to South America, which were recently reclassified in three genera (Cheracebus, Plecturocebus and Callicebus). The genus Callicebus, which currently includes five species, is endemic to eastern Brazil, occurring in the Caatinga, Savanna, and Atlantic Forest biomes. In the present study, we investigated the validity of these species and inferred their phylogenetic relationships, divergence times, and biogeographic patterns based on the molecular analysis of a concatenated sequence of 11 mitochondrial and nuclear DNA markers, derived from 13 specimens. We ran Maximum Likelihood (ML) and Bayesian Inference (BI) analyses, and estimated genetic distances, divergence times. Ancestral areas were estimated on BioGeoBears. Our results suggest that at about twelve million years ago, the ancestor of all titi monkeys inhabited a wide area that extended from the Amazon forest to the South of the Atlantic forest. A first vicariant event originated Cheracebus in the West of the Amazon and the ancestor of Callicebus and Plectorocebus which, later were separated by a second one. The diversification of Callicebus occurred during the Plio-Pleistocene (beginning at 5 Ma) probably influenced by climatic fluctuations and geological events. Therefore, the results of the present work confirmed the existence of five species that currently inhabit forested areas under increasing threat from human activities. Thus, a reliable diagnosis of the taxonomic status of species living in endangered environments is extremely important for the development of conservation measures.
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line transect surveying of arboreal monkeys problems of group size and spread in a highly fragmented landscape
American Journal of Primatology, 2010Co-Authors: Stephen F. Ferrari, Renata R D Chagas, Joao Pedro SouzaalvesAbstract:Line transect surveying is a relatively rapid and efficient procedure for the assessment of primate populations; although the reliability of the resulting density estimates is affected by a number of factors, including habitat configuration. In this study, primate populations were surveyed at a highly fragmented site in northeastern Brazil, where the resident species include the endangered Coimbra-Filho’s titi, Callicebus coimbrai, and the critically endangered yellow-breasted capuchin, Cebus xanthosternos .I n addition to standard line transect surveys, data were collected on the composition and distribution of resident groups during playback surveys and ecological monitoring. During surveys, a 5.3-km trail system was walked regularly over a 7-month period, accumulating a total transect length of 476 km and 104 sightings of Callicebus and 41 of Cebus (as well as 19 records of a third primate, Callithrix jacchus). Data were analyzed using the DISTANCE program and the Kelker method, using the perpendicular distances to first animal sighted. Estimates of group density were highly discrepant from known values for both species; although in the case of Cebus, this seemed to reflect grouping patterns at the site. For Callicebus, population density was overestimated considerably when known group counts were used. Overall, there seems to be a need for a much more rigorous standardization of procedures, and the analysis and presentation of results, in order to guarantee the most reliable interpretation possible of the data. These considerations are especially important in the case of endangered species, such as those studied here. Am. J. Primatol. 72:1100–1107, 2010. r 2010 Wiley-Liss, Inc.
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Titi monkeys (Callicebus spp., Atelidae : Platyrrhini) in the Brazilian state of Rondonia
Primates, 2000Co-Authors: Stephen F. Ferrari, Simone Iwanaga, Mariluce Rezende Messias, Eleildon M. Ramos, Paulo C. S. Ramos, Ernesto H. Da Cruz Neto, Paulo E. G. CoutinhoAbstract:Five species of titi monkey (Callicebus brunneus, Callicebus caligatus Callicebus cinerascens, Callicebus donacophilus, andCallicebus moloch) were recorded in surveys of primate populations at 26 sites throughout the Brazilian state of Rondonia. The distribution of the two species,C. cinerascens andC. donacophilus (recorded in the state for the first time), appeared to be related to that of non-forest ecosystems, the former in thecerrado woodlands, and the latter in gallery forests of the Guapore grasslands. The results of the surveys also indicate thatC. brunneus has a more restricted distribution in southern Rondonia than was previously thought, whereasC. moloch is more widespread. However, the ecological factors that determine species distribution in the south of the state remain unclear on the basis of the available data. All species were observed in small social groups of no more than five individuals, which are typical of the genus, generally in the middle and lower forest strate.
