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effects of patch size on feeding associations in muriquis (brachyteles arachnoides).data were collected on one group of muriquis, or woolly spider monkeys (brachyteles arachnoides) during a 14-month study at fazenda montes claros, minas gerais, brazil to examine the effects of food patch size on muriqui feeding associations. muriqui food patches were larger than expected from the availability of patch sizes in the forest; fruit patches were significantly larger than leaf patches. feeding aggregate size, the maximum number of simultaneous occupants, and patch occupancy time were ...19892807095
[a new natural host of plasmodium simium and plasmodium brasilianum: the woolly spider monkey]. 19684974015
fate of a redundant gamma-globin gene in the atelid clade of new world monkeys: implications concerning fetal globin gene expression.conclusive evidence was provided that gamma 1, the upstream of the two linked simian gamma-globin loci (5'-gamma 1-gamma 2-3'), is a pseudogene in a major group of new world monkeys. sequence analysis of pcr-amplified genomic fragments of predicted sizes revealed that all extant genera of the platyrrhine family atelidae [lagothrix (woolly monkeys), brachyteles (woolly spider monkeys), ateles (spider monkeys), and alouatta (howler monkeys)] share a large deletion that removed most of exon 2, all ...19957535927
a re-evaluation of subspecific variation and canine dimorphism in woolly spider monkeys (brachyteles arachnoides).a recent study suggests that differing populations of woolly spider monkeys exhibit a substantial degree of morphological, cytogenetic, and behavioral variation. we re-evaluate the differences between populations in the degree of canine tooth height sexual dimorphism and in the frequency of thumbs. statistical analysis of variation in the degree of canine sexual dimorphism between these populations fails to provide strong evidence for subspecific variation: differences in the degree of canine di ...19947864064
habitat, density and group size of primates in a brazilian tropical forest.habitats, population densities and group sizes of 5 primate species (callithrix flaviceps, callicebus personatus personatus, cebus apella nigritus, alouatta fusca clamitans, and brachyteles arachnoides) were estimated, using the method of repeated transect sampling, in an area of montane pluvial forest in eastern brazil (atlantic forest). a. fusca and c. apella had the highest densities in terms of groups and individuals per square kilometer, respectively, while b. arachnoides was least abundant ...19938206419
the enterobiinae subfam. nov. (nematoda, oxyurida) pinworm parasites of primates and rodents.recent redescriptions of most members of the oxyuridae cobbold, 1864 parasitic in primates revealed that they share following derived characters: sexual dimorphism of lateral alae (single-crested in the males, double-crested in the females); in males a second pair of genital papillae always surrounded by strongly cuticularized rings; in females, uterine tube divided into 2 parts by a cellular wall forming a diaphragm. these characters are interpreted as synapomorphies, providing evidence that th ...19968690538
a complete skeleton of the giant south american primate protopithecus.a complete skeleton of a large-bodied new world monkey has been found in pleistocene cave deposits in the brazilian state of bahia. it demonstrates an unprecedented combination of body size, locomotor and cranial morphology. skeletal features indicate an animal of approximately 25 kg, more than twice the mass of any living south american monkey. we refer the specimen to protopithecus brasiliensis lund, 1838, a large pleistocene primate originally represented by only a proximal femur and distal h ...19968692267
a new extinct primate among the pleistocene megafauna of bahia, brazil.a nearly complete skeleton of a robust-bodied new world monkey that resembles living spider monkeys was recovered from undisturbed pleistocene deposits in the brazilian state of bahia. the skeleton displays the highly specialized postcranial pattern typical of spider and woolly spider monkeys and shares cranial similarities to the spider monkey exclusively. it is generically distinct on the basis of its robustness (>20 kg) and on the shape of its braincase. this new genus indicates that new worl ...19968692827
dna evidence on the phylogenetic systematics of new world monkeys: support for the sister-grouping of cebus and saimiri from two unlinked nuclear genes.previous inferences from epsilon-globin gene sequences on cladistic relationships among the 16 extant genera of ceboidea (the new world monkeys) were tested by strength of grouping and bootstrap values for the clades in the most parsimonious trees found: for this epsilon data set enlarged with additional cebus and saimiri orthologues; for another nuclear dna sequence data set consisting of irbp (interstitial retinol-binding protein gene) intron 1 orthologues; and for tandemly combined epsilon an ...19958845968
stable isotope ratios indicate diet and habitat use in new world monkeys.this paper demonstrates the use of stable isotope ratios of carbon and nitrogen in animal tissue for indicating aspects of species behavioral strategy. we analyzed hair from individuals representing four species of new world monkeys (alouatta palliata, the mantled howler; ateles geoffroyi, the spider monkey; cebus capucinus, the capuchin; and brachyteles arachnoides, the woolly-spider monkey or muriqui) for delta 13c and delta 15n using previously developed methods. there are no significant diff ...19979185952
behavioral and endocrine characteristics of the reproductive cycle in wild muriqui monkeys, brachyteles arachnoides.the analysis of fecal ovarian steroids provides a powerful noninvasive method to obtain insights into ovulatory cycles, gestation length, and the timing of sexual interactions relative to the periovulatory period in wild primates. techniques developed to collect and assay feces from free-ranging muriqui monkeys (brachyteles arachnoides) for estradiol and progesterone yield the first explicit reproductive data on this species, and provide the first opportunity to evaluate the timing of observed c ...19979261511
steroid excretion during the ovarian cycle in captive and wild muriquis, brachyteles arachnoides.urine, feces, and copulation frequency were collected from two captive muriqui females, brachyteles arachnoides, at the centro de primatologia do rio de janeiro following the resumption of postpartum ovarian cycles. fecal steroid profiles from seven wild muriqui females at the estação biologica de caratinga, minas gerais, brazil, were compared to the captive females to determine the approximate patterns of steroid excretion relative to the urinary lh peak. hormonal profiles from one of the capti ...19979261512
lack of pubertal influences on female dispersal in muriqui monkeys, brachyteles arachnoides.the hormonal mediation of dispersal in female mammals is poorly understood, in part because of the difficulties of detecting the onset of ovarian cycling and puberty in dispersing individuals. we used noninvasive methods of faecal steroid assays to determine the timing of dispersal relative to puberty and ovarian cycling in wild female muriqui monkeys, a species in which males are philopatric and nearly all females transfer from their natal groups. natal females had a mean+/-se age of 73.4+/-7.2 ...200010792940
timing of births in sympatric brown howler monkeys (alouatta fusca clamitans) and northern muriquis (brachyteles arachnoides hypoxanthus).we monitored the birth patterns of sympatric brown howler monkeys (alouatta fusca clamitans) and northern muriquis (brachyteles arachnoides hypoxanthus) during a 4-yr period from october 1996 to august 2000 at the estação biológica de caratinga, minas gerais, brazil. brown howler monkey births (n = 34) occurred throughout the year, and birth frequencies did not differ between rainy and dry season months. the aseasonal birth patterns of the howler monkeys differed significantly from the dry seaso ...200111668527
age at first reproduction in philopatric female muriquis ( brachyteles arachnoides hypoxanthus).female northern muriquis ( brachyteles arachnoides hypoxanthus or b. hypoxanthus) at the estação biológica de caratinga/rppn-fma, minas gerais, brazil typically disperse from their natal groups at an average age of 6.1+/-0.6 years (median =6.0 years, range =5.3-7.8 years, n =22), prior to the onset of puberty and sexual activity. immigrants do not conceive until at least their second mating season, and the minimum interval from immigration to first reproduction has been 2.0 years. age at first r ...200414505181
hormonal changes during the mating and conception seasons of wild northern muriquis (brachyteles arachnoides hypoxanthus).we investigated hormonal and behavioral changes in wild male and female northern muriquis (brachyteles arachnoides hypoxanthus) at the estação biológica de caratinga, minas gerais, brazil, during a 6-mo period that encompassed the onset of the 1998-1999 mating and conception seasons. individual females resumed mating with the resumption of ovarian cycling, which was not synchronized among them or related to their cortisol levels. females experienced two to seven cycles prior to conceiving, and t ...200314582130
diet of a muriqui group (brachyteles arachnoides) in continuous primary forest.the feeding behaviour of a group of free-ranging muriquis (brachyteles arachnoides) was monitored in the 380 km(2) carlos botelho state park (pecb), between february 1992 and november 1993. scan sample data indicated that 59.1% of feeding time was devoted to fruit, 33.2% to leaves, 4.1% to flowers, and 3.6% to other items (twigs, stem and bark). little seasonal variation was recorded. these results contrast with those of all previous studies of brachyteles, in which the consumption of leaves was ...200415042413
vocal sequential exchanges and intragroup spacing in the northern muriqui brachyteles arachnoides hypoxanthus.sequential exchanges of vocalizations (staccatos and neighs) emitted by northern muriquis brachyteles arachnoides hypoxanthus were recorded at the biological station of caratinga, minas gerais state, brazil. staccatos and neighs containing larger proportion of short elements were preferentially produced during short-range exchanges; neighs, produced by a larger number of participants, were typical of long-range exchanges. staccatos emitted by animals feeding in a dispersed manner contained a lar ...200415258657
phylogenetic inferences of atelinae (platyrrhini) based on multi-directional chromosome painting in brachyteles arachnoides, ateles paniscus paniscus and ateles b. marginatus.we performed multi-directional chromosome painting in a comparative cytogenetic study of the three atelinae species brachyteles arachnoides, ateles paniscus paniscus and ateles belzebuth marginatus, in order to reconstruct phylogenetic relationships within this platyrrhini subfamily. comparative chromosome maps between these species were established by multi-color fluorescence in situ hybridization (fish) employing human, saguinus oedipus and lagothrix lagothricha chromosome-specific probes. the ...200515545728
polymorphism of visual pigment genes in the muriqui (primates, atelidae).colour vision varies within the family atelidae (primates, platyrrhini), which consists of four genera with the following cladistic relationship: {alouatta[ateles (lagothrix and brachyteles)]}. spider monkeys (ateles) and woolly monkeys (lagothrix) are characteristic of platyrrhine monkeys in possessing a colour vision polymorphism. the polymorphism results from allelic variation of the single-locus middle-to-long wavelength (m/l) cone opsin gene on the x-chromosome. the presence in the populati ...200616448420
spider monkey, muriqui and woolly monkey relationships revisited.the taxonomic relationships among the four genera of the atelidae family, alouatta (howler), ateles (spider), lagothrix (woolly) and brachyteles (muriqui), have been the subject of great debate. in general, almost all authors agree with the assignment of howler monkeys as the basal genus, either in its own tribe alouattini or in the subfamily alouattinae, but they disagree on the associations among the other members of the family. muriquis have been grouped with spider monkeys based on the fact ...200717006741
ocelot (leopardus pardalis) predation on primates in caratinga biological station, southeast brazil.this study demonstrates that ocelots (leopardus pardalis) extensively use primates as a food resource at the caratinga biological station (cbs) in southeast brazil. analysis of 60 fecal samples collected over 4 years revealed predation upon the brown howler monkey (alouatta guariba), the muriqui (brachyteles hypoxanthus), and the brown capuchin monkey (cebus apella). the most frequent items found in the fecal samples analyzed were calomys (n=16) and non-identified aves (n=15), followed by a. gua ...200717330310
fruit diet of alouatta guariba and brachyteles arachnoides in southeastern brazil: comparison of fruit type, color, and seed size.fruit is an important food resource for neotropical primates. in this study i compare the fruit diet of sympatric brown howlers (alouatta guariba) and southern muriquis (brachyteles arachnoides). feeding behavior was studied over 12 months and fruit species consumed were identified and assigned to the categories fruit type, fruit color, and seed size. observed-fruit feeding records were compared with expected records determined from local availability of the fruit of the tree species. i also det ...200817578654
habitat quality of the woolly spider monkey (brachyteles hypoxanthus).this study examines how habitat structure affects the home range use of a group of brachyteles hypoxanthus in the brigadeiro state park, brazil. it has been reported that most of the annual feeding time of woolly spider monkeys is spent eating leaves, but they prefer fruits when available. we hypothesise that the protein-to-fibre ratio (pf; best descriptor of habitat quality for folivorous primates) is a better descriptor of habitat quality and abundance for these primates than the structural at ...200919887817
long-term field studies: positive impacts and unintended consequences.long-term field studies of wild primates can have far-reaching impacts that transcend their contributions to science. these impacts can benefit not only the study animals, study areas, and local human communities, but they can also have unintended, potentially negative consequences. examples of some of the positive impacts from the northern muriqui project of caratinga, in minas gerais, brazil, include contributions to conservation efforts on behalf of this critically endangered species, capacit ...201020653002
synteny of human chromosomes 14 and 15 in the platyrrhines (primates, platyrrhini).in order to study the intra- and interspecific variability of the 14/15 association in platyrrhini, we analyzed 15 species from 13 genera, including species that had not been described yet. the dna libraries of human chromosomes 14 and 15 were hybridized to metaphases of alouatta guariba clamitans, a. caraya, a. sara, ateles paniscus chamek, lagothrix lagothricha, brachyteles arachnoides, saguinus midas midas, leontopithecus chrysomelas, callimico goeldii, callithrix sp., cebus apella, aotus nig ...200921637455
genetic diversity and population history of a critically endangered primate, the northern muriqui (brachyteles hypoxanthus).social, ecological, and historical processes affect the genetic structure of primate populations, and therefore have key implications for the conservation of endangered species. the northern muriqui (brachyteles hypoxanthus) is a critically endangered new world monkey and a flagship species for the conservation of the atlantic forest hotspot. yet, like other neotropical primates, little is known about its population history and the genetic structure of remnant populations. we analyzed the mitoch ...201121694757
the making of platyrrhine semifolivores: models for the evolution of folivory in primates.among living new world monkeys, howlers and muriquis are by far the most folivorous. we examine how well the morphology and behavior of alouatta and brachyteles conform to leaf-eating adaptational models derived from other studies. both genera match these expectations unevenly, which suggests a broader conception of primate folivory is in order. hence the notion of "semifolivory." while their dentitions prove highly sensitive to selection for leaf-eating, core features relating to body size, bra ...201122042497
Low paternity skew and the influence of maternal kin in an egalitarian, patrilocal primate.Levels of reproductive skew vary in wild primates living in multimale groups depending on the degree to which high-ranking males monopolize access to females. Still, the factors affecting paternity in egalitarian societies remain unexplored. We combine unique behavioral, life history, and genetic data to evaluate the distribution of paternity in the northern muriqui (Brachyteles hypoxanthus), a species known for its affiliative, nonhierarchical relationships. We genotyped 67 individuals (22 infa ...201122065786
detection of toxoplasma gondii in two southern wooly spider monkeys (brachyteles arachnoides-geoffroy, 1806) from the rio de janeiro primate center, brazil.toxoplasmosis led to the death of two brachyteles arachnoides, an endangered atelid.201424757733
atlantic-frugivory: a plant-frugivore interaction dataset for the atlantic forest.the dataset provided here includes 8320 frugivory interactions (records of pairwise interactions between plant and frugivore species) reported for the atlantic forest. the dataset includes interactions between 331 vertebrate species (232 birds, 90 mammals, five fishes, one amphibian and three reptiles) and 788 plant species. we also present information on traits directly related to the frugivory process (endozoochory), such as the size of fruits and seeds and the body mass and gape size of frugi ...201728317110
membrane-plate transition in leaves as an influence on dietary selectivity and tooth form.primates need accurate sensory signals about food quality to forage efficiently. current evidence suggests that they target leaf foods based on color at long-range, reinforcing this with post-ingestive sensations relating to leaf toughness evoked during chewing. selection against tough leaves effectively selects against high fiber content, which in turn gives a greater opportunity of acquiring protein. here we consider a novel intermediate mechanical factor that could aid a folivore: leaves may ...201627265521
a current perspective on the historical geographic distribution of the endangered muriquis (brachyteles spp.): implications for conservation.the muriqui (brachyteles spp.), endemic to the atlantic forest of brazil, is the largest primate in south america and is endangered, mainly due to habitat loss. its distribution limits are still uncertain and need to be resolved in order to determine their true conservation status. species distribution modeling (sdm) has been used to estimate potential species distributions, even when information is incomplete. here, we developed an environmental suitability model for the two endangered species ...201626943910
female and male life tables for seven wild primate species.we provide male and female census count data, age-specific survivorship, and female age-specific fertility estimates for populations of seven wild primates that have been continuously monitored for at least 29 years: sifaka (propithecus verreauxi) in madagascar; muriqui (brachyteles hypoxanthus) in brazil; capuchin (cebus capucinus) in costa rica; baboon (papio cynocephalus) and blue monkey (cercopithecus mitis) in kenya; chimpanzee (pan troglodytes) in tanzania; and gorilla (gorilla beringei) i ...201626928014
first steps of bipedality in hominids: evidence from the atelid and proconsulid pelvis.upright walking absent a bent-hip-bent-knee gait requires lumbar lordosis, a ubiquitous feature in all hominids for which it can be observed. its first appearance is therefore a central problem in human evolution. atelids, which use the tail during suspension, exhibit demonstrable lordosis and can achieve full extension of their hind limbs during terrestrial upright stance. although obviously homoplastic with hominids, the pelvic mechanisms facilitating lordosis appear largely similar in both ta ...201626793418
functional redundancy and complementarities of seed dispersal by the last neotropical megafrugivores.functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. the two largest frugivores in the neotropics, tapirs (tapirus terrestris) and muriquis (brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectivene ...201323409161
chronology of deep nodes in the neotropical primate phylogeny: insights from mitochondrial genomes.the evolution of neotropical primates (np) is permeated by factors associated with the pattern of diversification and the biogeography of the major lineages. these questions can be better understood by providing a robust estimate of the chronological scenario of np evolution, a reason why molecular dating methods have been widely applied. one aspect of especial interest is the timing of diversification of the major np lineages (pitheciids, atelids and cebids), which may have resulted from rapid ...201223272145
feeding and resting postures of wild northern muriquis (brachyteles hypoxanthus).increased body size in brachyteles has been regarded as an important evolutionary adaptation that allowed a greater reliance on leaves compared to other more frugivorous atelidae, but its association with muriqui positional behavior and substrate use is still unknown. here, we present original data on the feeding and resting postures of the northern muriqui (brachyteles hypoxanthus) and evaluate predictions about the relationships between body size, postural behavior, and substrate use derived f ...201323070942
unexpected demography in the recovery of an endangered primate population.assessments of the status of endangered species have focused on population sizes, often without knowledge of demographic and behavioral processes underlying population recovery. we analyzed demographic data from a 28-year study of a critically endangered primate, the northern muriqui, to investigate possible changes in demographic rates as this population recovered from near extirpation. as the population increased from 60 to nearly 300 individuals, its growth rate declined due to increased mort ...201223028534
respiratory syncytial virus (rsv) pneumonia in a southern muriqui (brachyteles arachnoides).an adult male brachyteles arachanoides, kept in captivity since 1990, was found dead without apparent clinical evidence.201222931057
liver iron overloading in captive muriquis (brachyteles spp.).iron accumulation was investigated qualitatively and quantitatively in the liver of 15 captive brachyteles spp.201121087287
sex differences in vocal patterns in the northern muriqui (brachyteles hypoxanthus).we investigated whether sex differences in spatial dynamics correlate with rates of staccato and neigh vocalizations in northern muriquis (brachyteles hypoxanthus) at the reserva particular do patrimônio natural-feliciano miguel abdala, minas gerais, brazil. a total of 2,727 10 min focal subject samples were collected on 32 adult females and 31 adult males between april 2007 and march 2008. compared with males, females spent a significantly lower proportion of their time in proximity to other gr ...201019885910
mother-offspring associations in northern muriquis, brachyteles hypoxanthus.maternal care of offspring is ubiquitous among primates, but its duration varies across species due to factors such as dispersal patterns and social dynamics, which influence opportunities for and potential benefits of maternal investment in older offspring, respectively. we examined mother-offspring associations in wild northern muriquis (brachyteles hypoxanthus), in which males are philopatric, females typically disperse before puberty, and social relationships among and between males and fema ...200817910037
population demography of northern muriquis (brachyteles hypoxanthus) at the estação biológica de caratinga/reserva particular do patrimônio natural-felìciano miguel abdala, minas gerais, brazil.the 957-ha forest at the estação biológica de caratinga/reserva particular do patrimônio natural-felìciano miguel abdala, in minas gerais, brazil, supports one of the largest known populations of the critically endangered northern muriqui (brachyteles hypoxanthus). we combine long-term data on one group that has been monitored since 1982 with new data obtained on the other three groups since 2002 and 2003 to describe the demographic structure of this population, evaluate its potential for future ...200616365854
observations on genital morphology and anatomy of a hybrid male muriqui (genus brachyteles).the reproductive anatomy of the muriqui (genus brachyteles) is poorly known. this paper describes the anatomy of the testis, penis and striated penile muscles in a young adult (5.25-year-old) captive-born muriqui which died at the rio primate center. two forms of muriqui occur in the atlantic coastal forests of brazil, and both are endangered. the form which is found north of 21 degrees 00' s latitude is classified as b. hypoxanthus by some authorities and is considered to be a species separate ...201615010578
[insecticide resistance in simulium populations (diptera, simuliidae)].populations of simulium (chirostilbia) pertinax kollar, 1832 from southern and southeastern states of brazil were analyzed for temephos susceptibility considering control historical information and possible resistance. in situ bioassays were carried out for populations from the states of paraná (tibaji and rolândia), rio de janeiro (muriqui) and são paulo (barra do una, ilhabela and morungaba). the populations were characterized as susceptible (s) or resistant (r) by submitting larvae in the las ...201312048592
seasonal and social correlates of fecal testosterone and cortisol levels in wild male muriquis (brachyteles arachnoides).fecal testosterone and cortisol levels were analyzed from six wild male muriquis (brachyteles arachnoides) over a 19-month period at the estação biológica de caratinga in minas gerais, brazil, to investigate the hormonal correlates of seasonal sexual behavior and environmental conditions. group mean testosterone levels based on weekly samples from the six males did not differ between copulatory and noncopulatory periods or between rainy and dry seasons. cortisol levels did change with copulatory ...199910202120
predicting primate responses to "stochastic" demographic events.comparative approaches in contemporary primate behavioral ecology have tended to emphasize the deterministic properties of stochastic ecological variables. yet, primate responses to ecological fluctuations may be mediated by the interactions among demographic processes at the levels of individuals, groups, and populations. in this paper i examine long-term data collected from june 1982-july 1998 on one expanding group of muriquis (brachyteles arachnoides) at the estação biologica de caratinga, m ...199923179536
chromosomal phylogeny of lagothrix, brachyteles, and cacajao.based on a comparison of the karyotypes of two plathyrrhini species, cacajao melanocephalus (pitheciinae) and brachyteles arachnoides (atelinae), with those of two previously studied species, lagothrix lagothrica (atelinae) and c calvus rubicundus (pitheciinae), it appears that the two cacajao species have undergone the same number of chromosome rearrangements since they diverged from their common ancestor and that the karyotype of brachyteles is ancestral to that of lagothrix. the chromosomal p ...19854006525
dentition of brachyteles arachnoides with reference to alouattine and atelinine affinities. 19734211908
intra-community coalitionary lethal attack of an adult male southern muriqui (brachyteles arachnoides).we report on the first evidence of intra-community coalitionary lethal aggression in muriquis (brachyteles). the event occurred in southern muriquis (brachyteles arachnoides) during a long-term study (>15 years) of two social groups inhabiting mostly pristine atlantic forest habitat in the parque estadual carlos botelho, southern são paulo state, brazil. the attack took place deep in the core area of the group caetê home range. tense agonistic behaviors and vocalizations preceded the lethal coal ...200919489067
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