Patterns of mineral lick visitation by spider monkeys and howler monkeys in Amazonia: are licks perceived as risky areas?

Mineral licks--also known as "salados," "saladeros," or "collpas"--are specific sites in tropical and temperate ecosystems where a large diversity of mammals and birds come regularly to feed on soil. Although the reasons for vertebrate geophagy are not completely understood, animals are argued to obtain a variety of nutritional and health benefits from the ingestion of soil at mineral licks. We studied the temporal patterns of mineral lick use by white-bellied spider monkey (Ateles belzebuth) and red howler monkey (Alouatta seniculus) in a lowland rain forest in Amazonian Ecuador. Using camera and video traps at four different mineral licks, combined with behavioral follows of one group of spider monkeys, we documented rates of mineral lick visitation by both primate species and the relative frequency and intensity of mineral lick use by spider monkeys. On the basis of 1,612 days and 888 nights of mineral lick monitoring, we found that A. belzebuth and A. seniculus both visit mineral licks frequently throughout the year (on average ～14% of days for both species), and mineral lick visitation was influenced by short-term environmental conditions (e.g. sunny and dry weather). For spider monkeys, the area surrounding the lick was also the most frequently and most intensively used region within the group's home range. The fact that spider monkeys spent long periods at the lick area before coming to the ground to obtain soil, and the fact that both species visited the lick preferentially during dry sunny conditions (when predator detectability is presumed to be relatively high) and visited simultaneously more often than expected by chance, together suggest that licks are indeed perceived as risky areas by these primates. We suggest that howler and spider monkeys employ behavioral strategies aimed at minimizing the probability of predation while visiting the forest floor at risky mineral lick sites.     

Effects of predation risk on the grouping patterns of white‐bellied spider monkeys (Ateles belzebuth belzebuth) in Western Amazonia

Predation is proposed to be one of the most important factors influencing the evolution of mammalian societies. Although predation risk is thought to influence both the behavior and grouping patterns of most diurnal primates, evidence supporting this hypothesis is still limited. The spatial and temporal patterns of mineral lick use by one group of white‐bellied spider monkeys (Ateles belzebuth) were evaluated, based on the growing evidence that mineral licks are perceived as areas of relative high predation risk by Neotropical primates. The area immediately surrounding the mineral lick was the most intensively used area within the home range of the study group, particularly by large subgroups of monkeys, and there were differences in mean subgroup size on days of mineral lick visitation versus days without lick visits. Additionally, on days of mineral lick visitation, subgroup size reached its maximum specifically during the period of lick visitation. Finally, on visit days subgroups showed a greater increase in size and higher fusion rates in the 2 hr before arriving at the lick in comparison with matched time windows on non‐visit days. Together, these results provide an example of how primates employ behavioral strategies that might reduce the effects of predation. This study also demonstrates how taxa characterized by a high degree of fission‐fusion dynamics can allow us to test hypotheses regarding the effects of socioecological variables on primate grouping patterns. Am J Phys Anthropol 150:579–590, 2013. © 2013 Wiley Periodicals, Inc.     

Foraging,Food Choice,and Food Processing by Sympatric Ripe-Fruit Specialists: <Emphasis Type="Italic">Lagothrix lagotricha poeppigii</Emphasis> and <Emphasis Type="Italic">Ateles belzebuth belzebuth</Emphasis>

Studies of interspecific competition and niche separation have formed some of the seminal works of ecology. I conducted an 18-mo study comparing the feeding ecologies of 2 sympatric, closely-related ripe-fruit specialists, Humboldt's woolly monkeys (Lagothrix lagotricha poeppigii), and the white-bellied spider monkeys (Ateles belzebuth belzebuth) in Amazonian Ecuador. Woolly monkeys in the terra firme forest live at roughly triple the density of spider monkeys (31 versus 11.5 animals/km²). Woolly monkeys spend 17% of their time foraging, while spider monkeys spend only 1% of their time foraging. Spider monkeys alone fed on soil and termitaria, which are rich in phosphorus. Woolly monkeys are not hard-fruit specialists. Their fruit diet is significantly more diverse than that of spider monkeys. Dietary overlap between the 2 species is high, yet each specializes to some degree on a different set of fruit resources. Woolly monkeys visit more food sources per unit of time, feed lower in the canopy, visit more small food patches, and prey on more seeds. Spider monkeys feed on fewer, richer food sources and are more than twice as likely to return to a particular fruit source than woolly monkeys are. Spider monkeys maximize fruit pulp intake, carrying more intact seeds in their guts, while woolly monkeys minimize seed bulk swallowed through more careful food processing. Surprisingly, several preferred spider monkey foods with high fat content and large seeds are avoided by woolly monkeys. I outline the different ecological dimensions involved in niche separation between the 2 species and discuss the possible impetus for their evolutionary divergence.     

Terrestrial Behavior of <Emphasis Type="Italic">Ateles</Emphasis> spp

Spider monkeys (Ateles spp.) are well known for their highly arboreal lifestyle, spending much of their time in the highest levels of the canopy and rarely venturing to the ground. To investigate terrestriality by Ateles and to illuminate the conditions under which spider monkeys venture to the ground, we analyzed ad libitum data from 5 study sites, covering 2 species and 5 subspecies. Three of the sites are in Central/North America: Barro Colorado Island (BCI), Panama (Ateles geoffroyi panamensis), Santa Rosa National Park, Costa Rica (A. g. frontatus), and Punta Laguna, Mexico (A. g. yucatanensis). The 2 remaining sites are in South America: Cocha Cashu Biological Station, Perú (A. belzebuth chamek) and Yasuni National Park, Ecuador (A. b. belzebuth). Terrestrialism by Ateles at all sites is rare; however, it is more restricted at the 2 South American sites. In South America, ground use only occurred in the contexts of eating soil or rotten wood and visiting salt licks. In contrast at the 3 sites with Ateles geoffroyi it rarely occurred in a feeding context, but instead more frequently while drinking from streams during the dry season, by adult females escaping attack by adult males, and as part of a chase game. In addition, on BCI adult males were on the ground before attacking adult females. We discuss potential explanations, e.g., climate, species differences, predation pressure, for the differences between the Central/North and South American observations.     

Use of Mineral Licks by White-Bellied Spider Monkeys (<Emphasis Type="BoldItalic">Ateles belzebuth</Emphasis>) and Red Howler Monkeys (<Emphasis Type="BoldItalic">Alouatta seniculus</Emphasis>) in Eastern Ecuador

Geophagy occurs in all primate groups and is particularly common in species that consume greater quantities of plant material, i.e., leaves, fruit. The function of geophagy is not fully understood and likely varies over space and time, perhaps in connection with changes in diet. Central to a better understanding of geophagy in primate ecology is knowledge of the occurrence of such behavior among different species and seasons. We used camera traps triggered by heat and motion to document the use of mineral licks by primates over a 3-yr period at a lowland forest site in eastern Ecuador (Tiputini Biodiversity Station). Such mineral licks can be important sources of minerals, nutrients, and other compounds for a wide range of species in Amazonian forests. Although 10 species of primates are known from the study site, we obtained photographs of only 2 species, Ateles belzebuth (white-bellied spider monkey) and Alouatta seniculus (red howler) at 2 of 4 saladeros surveyed. From late December 2004 through early January 2008, we recorded 192 photographs with a total of 318 Ateles belzebuth representing ≥66 separate visits. Comparable numbers for Alouatta seniculus were 80, 121, and 37. We recorded both species visiting a mineral lick at the same time on ≥7 occasions. Use of mineral licks varied across months; we recorded more visits from November through February, the drier period at Tiputini. Visits also varied by hour, with no visits before 0830 or after 1630; Ateles belzebuth showed a stronger mid-day peak in visits. Average visit length (calculated as the time between the first and last photographs of a given visit) was similar between the 2 species but median visit length was more than twice as long for Ateles belzebuth (15 min) as for Alouatta seniculus (6 min). Results indicate that mineral licks are important in the ecology of these species, but further studies are needed to determine the precise benefit(s) obtained and how benefits may vary with diet and other factors.     

Diet and Travel Costs for Spider Monkeys in a Nonseasonal, Hyperdiverse Environment

I studied the effects of a nonseasonal environment with a high diversity of plant species in a community of white-bellied spider monkeys (Ateles belzebuth belzebuth) in the Yasuní National Park, Ecuador. During 10 2-wk follows of focal individuals across 1 yr, I collected 1268 h of observation data on ranging and foraging. The environment had strong effects on both the foraging and ranging behavior of the monkeys. Yasuní spider monkeys are similar to spider monkeys in more seasonal environments in that ripe-fruit consumption dominates the diet. However, Yasuní spider monkeys exhibit an extremely diverse diet that parallels the variety of foods available to them, consuming more than 238 species of fruits. The impressive dietary variety increased even more with increased observation time, as I had not previously observed in the spider monkeys’ diet 40% of the fruit species the subjects consumed during the final follow. Ripe fruits remain the most important item in the diet year-round, supplemented with decayed wood or leaf flush. Local rarity of plant species means that fruiting patches are an average of 420 m apart, and mean patch residence times are short, only 8.1 min. Visits to an average of 11.5 feeding patches/d lead to a mean daily path length of 3311 m, longer than reported for any other Ateles species, and long compared to most other primate species. The long daily paths of Yasuní spider monkeys reflect travel costs resulting from foraging in a hyperdiverse nonseasonal environment.     

Intra-community infanticide and forced copulation in spider monkeys: a multi-site comparison between Cocha Cashu, Peru and Punta Laguna, Mexico

We describe two cases of infanticide, two suspected infanticides, and a forced copulation by familiar resident males in two populations of wild spider monkeys (Ateles belzebuth chamek and A. geoffroyi yucatanensis). These are the first known infanticides and forced copulation in spider monkeys. Data were gathered from four neighboring communities of spider monkeys in Manu National Park at the Cocha Cashu Biological Station, Peru and two communities in the Otoch Ma'ax Yetel Kooh Reserve at Punta Laguna, Mexico, during intensive field studies of over 2,000 hr each. These are rare behaviors, but results suggest that mating history and sexual coercion are important in spider monkey social relationships.     

Locomotor behavior of Lagothrix lagothricha and Ateles belzebuth in Yasuní National Park, Ecuador: general patterns and nonsuspensory modes.

Field study of the locomotor behavior of sympatric woolly monkeys (Lagothrix lagothricha) and spider monkeys (Ateles belzebuth) in undisturbed rainforest of northern Ecuador revealed similar patterns in use of plant forms (categorized tree and liana structure), and substantial differences in the frequencies of use of different grouped modes (aggregates of kinematically similar specific modes). Lagothrix progressed more than Ateles by leaping/dropping and quadrupedal walking/running, whereas Ateles exhibited more suspensory locomotion. Grouped modes are associated with different plant forms in similar ways in the two species. In contrast, the species differed in use of tree zone (trunk/bole, major branches, intermediate branches, and terminal branches), with Lagothrix using intermediate branches and Ateles terminal branches more. Correlated with this difference was greater use by Lagothrix of quadrupedal movement, especially on intermediate branches, and greater use of suspensory modes by Ateles, especially in the terminal zone. Further research is needed to determine how these patterns are facilitated and constrained by morphological mechanisms. Analysis of specific locomotor modes within groups shows several interspecific differences in relative frequencies.     

Daily rhythm and seasonal pattern of lick use in sika deer (Cervus nippon) in China

Many ungulates are reported to use natural or artificial licks with seasonal patterns around the world. From December 2016 to August 2017, we used infrared camera to record the use of artificial licks in wild sika deer (Cervus nippon) in Zhejiang Qingliangfeng National Nature Reserve, China. We explored the daily rhythm, seasonal pattern and sex difference in lick utilization. In total, 12,043 videos and 22,901 pictures were collected. Our results showed that: (1) the lick visiting frequency was higher at night than that during daytime; (2) the difference in lick visiting frequency between females and males disappeared after taking into account of sex ratio; (3) the lick duration peaked in April during a year. These findings suggested that there were clear daily rhythm and seasonal pattern of lick use in sika deer. Seasonal change in lick use intensity was consistent with our prediction. These variations in lick use might be driven by both the physiological needs of the mineral elements in different life stages and the seasonal changes in climate and food. The reserve management authority should pay more attention to the supplement of licks in spring and summer to fulfill animal’s physiological needs.     

Suspensory locomotion of Lagothrix lagothricha and Ateles belzebuth in Yasuní National Park,Ecuador

A comparative field study of the locomotion of woolly monkeys (Lagothrix lagothricha) and spider monkeys (Ateles belzebuth) in undisturbed rainforest of northeastern Ecuador reveals substantial differences in their use of suspensory modes. Ateles performed both more brachiation (by forelimbs and tail, with trunk rotation), and forelimb swing (similar to brachiation, but without trunk rotation) than Lagothrix. In contrast, in Lagothrix 20% of suspensory movement was by pronograde forelimb swing, which resembles forelimb swing except that the body is held in a pronograde orientation due to the tail and/or feet intermittently grasping behind the trailing forelimb. Ateles never exhibited this mode. Both brachiation and forelimb swing by Ateles were more dynamic than in Lagothrix, consisting of higher proportions of full-stride bouts (versus single-step). Both species used smaller supports for suspensory than for quadrupedal locomotion, and Ateles used both smaller and larger supports for suspension than did Lagothrix. Analysis of support inclination shows that both species tended to perform more above-support movement on horizontal supports and more below-support (suspensory) movement from oblique supports. Our attempt to elucidate the aspects of canopy structure that favor suspension suggests the need for additional kinds of observational data, focusing on the "immediate structural context" of positional events.     

Nuclear DNA variation in spider monkeys (Ateles)

Phylogenetic relationships based on DNA sequence variation for the aldolase A intron V nuclear genomic region were evaluated and compared to phylogenies based on mitochondrial DNA sequence variation among spider monkeys (Ateles). Samples of Ateles ranging from Central America throughout the Amazon Basin were sequenced to determine phylogenetic relationships among geographically widely distributed populations. Analysis of nuclear DNA sequences using parsimony, maximum-likelihood, and genetic distance analyses produced similar phylogenies. Four previously proposed monophyletic species of spider monkeys were: (1) Ateles paniscus, composed of haplotypes from the northeastern Amazon Basin; (2) A. belzebuth, found in the western and southern Amazon Basin; (3) A. hybridus, located primarily along the Magdalena River valley of Colombia; and (4) A. geoffroyi, including all haplotypes found in the Choco region of South America and throughout Central America. The nuclear phylograms were analyzed based on associated bootstrap support and confidence probabilities. Support from the nuclear DNA genome was less robust than support from the mitochondrial DNA data, most likely due to a level of sequence variation, which was 90% less than that of the mitochondrial DNA genome. Nuclear DNA congruencies with mitochondrial DNA-based phylogenies, as supported by the incongruence length difference and winning sites tests, provide further support for the suggested revisions in Ateles taxonomy that are contradictory to long-held taxonomies based on pelage variation.     

Seasonal variation in association patterns of wild spider monkeys (<Emphasis Type="Italic">Ateles belzebuth belzebuth</Emphasis>) at La Macarena,Colombia

Spider monkeys exhibit a fission–fusion type of social organization. I studied party size and party composition in wild long-haired spider monkeys (Ateles belzebuth belzebuth) in three study periods at La Macarena, Colombia and found that overall party size was larger in the fruit-abundant season. Mean party size in which males were observed was relatively stable across seasons. In contrast, the mean party size of females varied. Females were observed in larger parties in the fruit-abundant season than in the fruit-scarce season. Moreover, whereas males associated with each other at an almost equal frequency across seasons, females associated with each other more frequently in the fruit-abundant season. Females with infants or small juveniles were more often in association with other individuals than were cycling females. The intensity of individual relationships varied according to season, such that even mothers and sons were not always strongly associated. In a large party, females with infants may gain from predation avoidance but they are at a disadvantage in terms of scramble competition. The balance between these factors may change with fruit availability and may influence party size in different periods. For males, party formation may facilitate the defense of resources from neighboring groups more than provide predation avoidance. Electronic Publication     

Male and female range use in a group of white‐bellied spider monkeys (Ateles belzebuth) in Yasuní National Park,Ecuador

Spider monkeys (Ateles sp.) live in a flexible fission–fusion social system in which members of a social group are not in constant association, but instead form smaller subgroups of varying size and composition. Patterns of range use in spider monkeys have been described as sex‐segregated, with males and females often ranging separately, females utilizing core areas that encompass only a fraction of the entire community range, and males using much larger portions of the community range that overlap considerably with the core areas of females and other males. Males are also reported to use the boundary areas of community home ranges more often than females. Spider monkeys thus seem to parallel the “male‐bonded” patterns of ranging and association found among some groups of chimpanzees. Over several years of research on one group of spider monkeys (Ateles belzebuth) in Yasuní National Park, Ecuador, we characterized the ranging patterns of adult males and females and evaluated the extent to which they conform to previously reported patterns. In contrast to ranging patterns seen at several other spider monkey sites, the ranges of our study females overlapped considerably, with little evidence of exclusive use of particular areas by individual monkeys. Average male and female home range size was comparable, and males and females were similar in their use of boundary areas. These ranging patterns are similar to those of “bisexually bonded” groups of chimpanzees in West Africa. We suggest that the less sex‐segregated ranging patterns seen in this particular group of spider monkeys may be owing to a history of human disturbance in the area and to lower genetic relatedness between males, highlighting the potential for flexibility some aspects of the spider monkeys' fission–fusion social system. Am. J. Primatol. 72:129–141, 2010. © 2009 Wiley‐Liss, Inc.     

Mineral licks as a sodium source for Isle Royale moose

Summary Natural mineral licks and their use by moose (Alces alces) on Isle Royale National Park, Michigan, were studied during 1982–85. The distribution of known licks suggested that they occurred in association with glacial debris, primarily in the western portions of the island. Moose utilized mineral springs extensively during the spring-summer period, and at least 5 licks were used year-round. During summer, a pronounced diel pattern of moose visitation was apparent, with peak use occurring between 0400–0800 h. Although daytime lick use declined by late June, morning and evening use continued to be relatively high throughout the study period. Peak lick use coincided with leaf-emergence in spring. Moose continued to utilize mineral licks despite the availability of ponds containing aquatic plants. Sodium appeared to be the element attracting moose to licks where they ingest copious amounts of water. Observed sodium ingestion rates (0.35 g/min) at licks indicate that licks provide a more concentrated source of sodium compared to aquatic plants (0.023 g/min). Based on the data presented, we reject the conclusions of earlier workers that aquatic plants constitute the only significant source of sodium for Isle Royale moose.     

Elemental analysis of mineral lick soils from the Serengeti National Park, the Konza Prairie and Yellowstone National Park

We analyzed mineral lick soils and non-mineral lick soils from the Serengeti National Park, the Konza Praine, and Yellowstone National Park The concentrations of 14 different elements considered important for ungulate nutrition were analyzed to determine the relative importance of Na vs other elements in attracting animals to lick areas Only Na was consistently higher in the mineral lick soils of the three ecosystems Mean Na concentrations were c 20x greater in Serengeti licks, 10x greater in Konza licks and 3x greater in Yellowstone licks compared to the respective non-lick soils Despite the numerous elements analyzed for this survey, our results suggest that Na is the primary element initiates mineral lick use in these widely separated ecosystems The widespread distribution of Na-deficient forage likely explains the importance of Na in most mineral licks     

Towing the party line: territoriality, risky boundaries and male group size in spider monkey fission-fusion societies

Spider monkey communities are classic fission-fusion primate societies. I present data suggesting that spider monkeys (Ateles chamek) at Lago Caiman are territorial; adult males traveled further and faster than adult females and subgroup size was significantly higher in boundary areas of the spider monkey territory where intercommunity disputes were observed than in non-boundary areas. I then go on to examine data from 20 Ateles communities distributed across 14 study sites and five species to investigate how a series of demographic, ecological and geographical parameters influence the number of males in a given spider monkey community. Analyses suggest that the number of males is not significantly related to the number of females in a community, the area of the community home range, or the total perimeter length of the community boundary. However, risky boundary perimeter length, or the length of perimeter that directly borders another spider monkey community, explains 88% of observed variations in the number of males in each community. I discuss the results in relation to spider monkey ecology and territoriality, as well as the potential of this relationship for explaining chimpanzee (Pan) behavior given their extremely similar fruit specialist, male philopatry, territoriality and fission-fusion social system.     

Effects of Seed Dispersal by Three Ateline Monkey Species on Seed Germination at Tinigua National Park, Colombia

We examined the effect of seed ingestion by three ateline primates: woolly monkeys, Lagothrix lagothricha; spider monkeys, Ateles belzebuth; and, red howler, Alouatta seniculus on germination rates and latency periods of seeds of several plant species in Tinigua National Park, Colombia. We collected dispersed seeds from feces and control seeds from the parental trees and washed them for germination trials. For the majority of plants, dispersed seeds germinated as well or better than control seeds did. Although spider monkeys depend more heavily on fruits than the other monkey species do, they were not more efficient than howlers or woolly monkeys at improving germination rates. A considerable proportion of the seeds dispersed by howlers and woolly monkeys showed reduced latency periods to germination, but spider monkeys showed less effect on reducing germination time. This result may be related to longer gut retention times, but such a trend has not been observed in other primate species. We conclude that, like many other primates, ateline monkeys are effective seed dispersers in terms of their effects on the seeds they swallow because they rarely decrease their germination rates. We discuss problems that make interspecific comparisons difficult, such as inappropriate control seeds and differences associated with germination substrates, and we stress the importance of studying other components of seed dispersal effectiveness.     

Chromosomal homologies between Cebus and Ateles (primates) based on ZOO-FISH and G-banding comparisons

ZOO-FISH (Fluorescent "in vitro" hybridization) was used to establish the chromosomal homology between humans (HSA) and Cebus nigrivitatus (CNI) and Ateles belzebuth hybridus (ABH). These two species belong to different New World monkey families (Cebidae and Atelidae, respectively) which differ greatly in chromosome number and in chromosome morphology. The molecular results were followed by a detailed banding analysis. The ancestral karyotype of Cebus was then determined by a comparison of in situ hybridization results, as well as chromosomal morphology and banding in other Platyrrhini species. The karyotypes of the four species belonging to the genus Cebus differ from each other by three inversions and one fusion as well as in the location and amounts of heterochromatin. Results obtained by ZOO-FISH in ABH are in general agreement with previous gene-mapping and in situ hybridization data in Ateles, which show that spider monkeys have highly derived genomes. The chromosomal rearrangements detected between HSA and ABH on a band-to-band basis were 27 fusions/fissions, 12 centromeric shifts, and six pericentric inversions. The ancestral karyotype of Cebus was then compared with that of Ateles. The rearrangements detected were 20 fusions/fissions, nine centromeric shifts, and five inversions. Atelidae species are linked by a fragmentation of chromosome 4 into three segments forming an association of 4/15, while Ateles species are linked by 13 derived associations. The results also helped clarify the content of the ancestral platyrrhine karyotype and the mode of chromosomal evolution in these primates. In particular, associations 2/16 and 5/7 should be included in the ancestral karyotype of New World monkeys.     

Positional Behavior of Black Spider Monkeys (Ateles paniscus) in French Guiana

Spider monkeys (Ateles) frequently use suspensory locomotion and postures, and their postcranial morphology suggests convergence with extant hominoids in canopy and food utilization. Previous studies of positional behavior in Ateles, have produced variable rates in the use of different positional activities. I investigated the positional behavior of black spider monkeys (Ateles paniscus) in a wet rain forest in French Guiana, and assessed differences in the rates of use of positional modes across studies. I also discuss the significance of suspensory activities in forest utilization. In French Guiana, Ateles confined travel and feeding locomotion on small and medium-sized moderately inclined supports in the main canopy. Tail-arm brachiation and clamber were their main traveling modes, while clamber was the dominant feeding locomotor mode. Small horizontal supports were predominant during their feeding. Suspensory postures accounted for more than half of feeding bouts, with tail-hang and tail-hind limb(s) hang being the dominant postures. Feeding occurred largely in tree crown peripheries with the prehensile tail anchored frequently above the monkey. They usually collected food items below or at the same level as the body. There is no difference among the postures they used to acquire and eat young leaves and fruit. My results agree with reports on the positional behavior of different species of spider monkeys at other sites. Despite the use of different methods, the same species exhibited more or less similar profiles in similar forests. Interspecific differences could be associated with morphological differences. Moreover, intraspecific differences could be attributed to forest structure. The findings suggest that the major part of biological information is independent of methods used in the several studies. Suspensory behavior facilitates the exploitation of the forest canopy by shortening traveling pathways between and within trees, by enabling faster travel for the better exploitation of patchy food sources and by providing access to food in the flexible terminal twigs.     

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 three species included in this study and four previously analyzed species from all four Atelinae genera were subjected to a phylogenetic analysis on the basis of a data matrix comprised of 82 discrete chromosome characters. The results confirmed that Atelinae represent a monophyletic clade with a putative ancestral karyotype of 2n = 62 chromosomes. Phylogenetic analysis revealed an evolutionary branching sequence [Alouatta [Brachyteles [Lagothrix and Ateles]]] in Atelinae and [Ateles belzebuth marginatus [Ateles paniscus paniscus [Ateles belzebuth hybridus and Ateles geoffroyi]]] in genus Ateles. The chromosomal data support a re-evaluation of the taxonomic status of Ateles b. hybridus.