Group sizes and compositions of monkeys in the upper Amazon basin

Eleven species of New World monkeys inhabit the basin of the upper Amazon. Twice, for a total 16 months, the author studied the group sizes and compositions of these species in the basin of the Rivers Caquetá and Putumayo, particularly in the two study areas established in the basin of the River Peneya, a tributary of the River Caquetá. Data obtained by the author were compared with those on the same and close relative species living in other places. And the author could conclude that each species, showing a considerable range of variation in group size and composition, has a common specificity for the social structure of the unit group.     

Length–weight relationships of sixteen freshwater fishes from the Hacha River and its tributaries (Amazon Basin,Caquetá, Colombia)

Body length and weight relationships were estimated for sixteen native freshwater fish species (ten Characidae, three Loricariidae, two Heptapteridae and one Astroblepidae, mainly small‐sized fish) collected in the Andean piedmont Hacha River (Caquetá, Colombia) by electrofishing. These are the first length–weight and length–length parameters reported for the species, which are mostly endemic to the Amazonian basin. Maximum lengths in eight of the sixteen studied species are also reported. Knowledge of this biometric data and their relationships can be relevant in the management and conservation of the local fish and fisheries.     

Paracoccidioidomycosis in wild monkeys from Paraná State, Brazil

The aim of this study was to evaluate the seroprevalence of Paracoccidioides brasiliensis infection in wild New World monkeys (Cebus sp. and Alouatta caraya). A total of 93 animals (Cebus sp., n = 68 and Alouatta caraya, n = 25) were captured in the Paraná River basin, Paraná State, Brazil and the serum samples were analyzed by ELISA and immunodiffusion using P. brasiliensis gp43 and exoantigen as antigens, respectively. The seropositivity observed by ELISA was 44.1% and 60% for Cebus sp. and A. caraya, respectively, while by immunodiffusion test Cebus sp. showed positivity of 2.9% only. No significant difference was observed in relation to age and sex. This is the first report of paracoccidioidomycosis in wild capuchin monkeys and in wild-black and golden-howler monkeys. The high positivity to P. brasiliensis infection in both species evaluated in our study and the positivity by immunodiffusion test in Cebus sp. suggest that natural disease may be occurring in wild monkeys living in paracoccidioidomycosis endemic areas.     

Species richness and distribution of understorey bryophytes in different forest types in Colombian Amazonia

Abstract

The first bryophyte survey results from Colombian Amazonia are presented. Bryophyte species, differentiated into mosses and liverworts, and further into four life-form classes, were sampled in 0.1-ha plots. These plots were distributed over four landscape units in the middle Caquetá area: floodplains, swamps, terra firme forests and white-sand areas. The total numbers of bryophyte species in the units were 50, 45, 45 and 32, respectively. The plots in floodplains and swamps were richer in moss species than the terra firme and white-sand plots, suggesting that coexistence of many moss species is favoured by high humidity. Moss species with fan life-forms preferred floodplains. On the other hand, liverwort species richness was highest in white-sand plots, which suggests that light incidence controls liverwort species-richness, perhaps more than humidity. All plots from the floodplain of the Caquetá River differed remarkably in species composition (of both mosses and liverworts) from the other landscape units. This may be due to the unique properties of this varzea system where, during yearly flooding events, soil, dead logs and stems are covered with a fresh layer of nutrient-rich fine silt, enhancing the surface for colonization and improving the conditions for productive bryophyte growth compared with elsewhere in the middle Caquetá area.     

Color discrimination by the cotton-top tamarin (Saguinus oedipus oedipus) and its relation to fruit coloration

Old World monkeys and apes have been reported to differ from New World monkeys in their abilities to discriminate colors across the visible spectrum. Old World monkeys and apes (Macaca, Pan, Pongo) discriminate colors quite accurately, while some New World monkeys studied (Saimiri, Cebus) have shown lower sensitivity to and poorer discrimination of long wavelength light. This study examined the color discrimination ability of another New World primate, the cotton-top tamarin, Saguinus oedipus oedipus (family Callitrichidae). The tamarins were trained to discriminate a set of Munsell color chips, both within the same hue category and from the 2 hue categories on either side of the training hue. Results indicated that the cotton-top tamarin can make accurate discriminations across the visible spectrum. Human subjects were tested under similar conditions in order to compare their color discrimination abilities to those of the tamarins. The tamarins and human subjects had the most difficulty discriminating the same hues. The discrimination abilities of the monkeys were assessed in relation to the coloration of fruits eaten in a natural environment. A list of the species of fruits commonly eaten by various species of New World monkeys was compiled and the coloration of fruits at maturity was noted. It was found that most New World primate species eat fruits whose mature coloration ranges across most of the spectrum.     

Habitat use and ecology of Wattled Curassows on islands in the lower Caquetá River,Colombia

ABSTRACT Despite being endangered, little is known about the natural history and habitat use of Wattled Curassows (Crax globulosa). From September 2008 to March 2009, we examined habitat associations of this species on three islands in the lower Caquetá River, Colombia. Observations of curassows were made during line‐transect walks, and habitat variables were measured at points where curassows were and were not observed along those transects to assess potential habitat preferences. A total of 182 sightings yielded encounter rates ranging from 0.1 to 0.89 observations/km across transects. Curassows were more likely to be observed close to the river and to lakes on the islands. Additionally, the importance of the river increased as the distance to internal water sources increased. Other habitat characteristics, including tree density, tree diameter, understory density, and canopy cover, did not differ between areas where Wattled Curassows were and were not observed. Flock size ranged from 1 to 9 individuals; most solitary individuals were males and flocks (>2 individuals) generally consisted of more females than males. The association of Wattled Curassows with water sources during the low‐water season may have conservation implications because it could increase their vulnerability to anthropogenic activities such as agricultural activities, fishing, and hunting. As a result, conservation of these curassows on islands in the lower Caquetá River will likely depend on local support.     

Olfactory discrimination of urine odors from five species by tufted capuchin (Cebus apella)

Urine collected from New World monkeys (tufted capuchin, squirrel monkey, cotton-top tamarin) and Old World monkeys (rhesus macaque, Japanese macaque), was used as the odor stimuli. Two adult tufted capuchins were trained on a successive odor-discrimination task with two odors, 30 trials each, in one session per day. Responses to one of the two odors (S+) were reinforced by sweet water. The monkeys failed to discriminate between the urine from the two species of macaques but could discriminate among the urine from the three species of New World monkeys. Furthermore, similarity of urine odors was analyzed by multi-dimensional scaling (MDS) and a cluster analysis. These analysis suggested that the tufted capuchin can distinguish differences among New World monkeys but not between the macaques. The natural distribution of the tufted capuchin overlaps with that of other New World monkeys, but it does not overlap with those of Old World monkeys. Consequently, it can be concluded that this difference in olfactory recognition in the tufted capuchin reflects their sympatric and allopatric relationships with other species.     

Yellow-eyed piranhas produce louder sounds than red-eyed piranhas in an invasive population of Serrasalmus marginatus

Serrasalmus marginatus is a piranha species native from the lower Paraná River basin and has been invasive in the upper Paraná River basin since the 1980s. In piranhas, sounds of different species have different features. The aim of this study was to investigate if the sounds produced by this species could be used to distinguish two morphotypes: red- and yellow-eyed S. marginatus from the Araguari River (upper Paraná River basin). All the temporal and frequency features of the sounds were equivalent in both groups of eye colour; it corresponds to the species-specific signature described for S. marginatus. Nonetheless, the amplitude features were all statistically different between red- and yellow-eyed piranhas. Yellow-eyed specimens produced louder sounds. In different fish species, colour change in eyes can be due to the absence or the presence of a dominant allele. It can also be involved in social rank or during reproduction. Different hormones and neuropeptides can modulate vocal features. It is hypothesized that a mutation or different hormonal concentrations could explain both sound amplitude and eye colour playing a role in animal communication in S. marginatus.     

Comparative anatomy of brain monoaminergic neurons in New World and Old World monkeys

A comparison of the distribution of brain monoamine neurons in several New World and Old World monkeys was undertaken using the Falck-Hillarp formaldehyde histofluorescence technique. The overall organization of the monoamine neurons was very similar in all species, although subtle variations were found. Catecholamine (noradrenaline and dopamine) and indoleamine (serotonin) cell bodies corresponding to groups A1–A7, A8–A10, and B1–B9, respectively were found throughout the brainstem. A few catecholamine (dopamine) cells equivalent to groups All and A12 in the diencephalon were also observed. Noradrenaline neurons, rather than those of the dopamine and serotonin systems, tended to be less numerous in the New World monkeys. Ascending catecholamine and indoleamine fiber bundles were observed in most monkeys. It is interesting that fibers corresponding to the “ventral noradrenaline bundle” appeared to be much finer in the common marmoset and tamarin than in other species. In addition, a substantial catecholamine (noradrenaline) innervation of the diencephalon was noted in all the Old World monkeys, while a much lower overall terminal density was apparent in the New World forms.     

Comparison of muscle weight and force ratios in New and Old World monkeys

Thin mandibles and small incisors found in New World monkeys as compared with Old World monkeys suggest that there may be differences in craniofacial loading patterns between these two groups, particularly in levels of mandibular corpus twisting (Hylander, 1975, 1979a; Eaglen, 1984; Bouvier, 1986a,b). This study examined the hypothesis that changes in the relative force contributions of the masticatory muscles were responsible for lowering torsion on the mandibular corpus in New World monkeys. Muscle weight and physiological cross-sections were compared using data from the literature (Schumacher, 1960: Turnbull, 1970; Cachel, 1979) as well as new data on adult male Cebus apella and Macaca mulatta. Both age and sex had an effect on muscle ratios. Mixed samples such as those used by Schumacher and Turnbull probably are not appropriate for drawing conclusions concerning species or group differences in muscle ratios. In addition, biomechanical conclusions based on muscle weight ratios alone to estimate muscle force may be misleading because fiber length inversely affects the amount of force a muscle can exert. A comparison of ratios based on physiological cross-section as an estimator of muscle force in New and Old World monkeys does not support the hypothesis that alterations in force contribution by individual masticatory muscles are responsible for minimizing mandibular corpus twisting in New World monkeys. Therefore, if twisting has been minimized in New World monkeys as suggested by their thin corpora, other changes in the craniofacial musculoskeletal complex, such as different muscle recruitment or pinnation patterns, may be responsible.     

Spatial segregation in the reproductive activity of Neotropical fish species as an indicator of the migratory trait

This study focused on the distribution of fish with high reproductive activity along a basin, using a 430 km stretch of the Cuiabá River in Brazil as a model. The main objective of this study was to identify those fish that migrate long distances for reproduction, among all the basin species. Thus, a set of working criteria are proposed to classify species according to their reproductive behaviour (i.e., reproductive activity and distribution). Samplings were performed in the Cuiabá River basin, encompassing several environments (river, channels and lakes) during the reproductive periods (between October and February), from 2000 to 2004. Species occurrence (presence and absence – proxy of distribution) across the basin and index of reproductive activity values were used as criteria to identify the species that perform long-distance longitudinal migrations for reproduction. The study confirmed the classification of long-distance longitudinal migration species; nonetheless, some species were not classified as described in the literature. The proposed sequential criteria have proven to be effective in the classification of long-distance longitudinal migrations species and certainly contribute to filling some existing knowledge gaps of reproductive traits. This classification is of fundamental importance in planning new dam projects, in decision making and in the development of management and conservation actions for the ichthyofauna.     

Diet composition of the electric eel Electrophorus voltai (Pisces: Gymnotidae) in the Brazilian Amazon region

The diet composition of the electric eel Electrophorus voltai was studied in specimens collected from the River Jari, state of Amapá, eastern Amazon region, Brazil. Analysis on their stomach contents revealed that fish, especially Megalechis thoracata, were the most frequent prey item, whereas arthropods and plant material were the least frequent intakes. This is the first stomach content analysis on E. voltai, and it corroborates that electric eel species are piscivorous.     

Biomechanical scaling of mandibular dimensions in New World Monkeys

Previous studies show that folivorous Old World monkeys have shorter, deeper mandibles and shorter, wider condyles than frugivorous ones. These morphologies have been related to leaf mastication in colobines and ingestion of large, tough fruits in cercopithecines. This study examines New World monkeys in order to determine whether they exhibit similar adaptations to diet. New World monkeys have relatively long, transversely thin mandibles and somewhat deep mandibles and narrow condyles. Except for their deep mandibles, folivorous New World monkeys (i.e., Alouatta) do not exhibit the mandibular and condylar specializations typical of cercopithecid folivores. Reliance on comparatively nonfibrous foods plus alterations in masticatory muscle ratios among New World monkeys partially accounts for observed differences between folivorous New and Old World monkeys. In addition, adaptations for howling in Alouatta appear to have a significant effect on mandibular morphology. A biomechanical interpretation of craniofacial scaling patterns suggests that the mandibles of New World monkeys are subjected to lower condylar loads and considerably less twisting of the mandibular corpus than those of comparable Old World monkeys.     

Comparative normal levels of serum triiodothyronine and thyroxine in nonhuman primates.

Normative values were obtained for triiodothyronine and thyroxine from four species of Old World primate (chimpanzees, rhesus monkeys, African green monkeys and talopoin monkeys) and a single species of New World primate (squirrel monkeys) represented by two subspecies, Colombian and Bolivian. The Bolivian squirrel monkeys exhibited the lowest values for both triiodothyronine and thyroxine. Male talapoins had the highest levels of thyroxine. Significant differences were found in levels of triiodothyronine and thyroxine between males and females of the same species and between the two subspecies of squirrel monkeys. Triiodothyronine:thryroxine ratios were consistently lower in the males of all species examined.     

Behavioral and hormonal aspects of reproduction in captive goeldi’s monkeys (Callimico goeldii) in a comparative and evolutionary context

The fate of most nonhuman primate species is intimately related to man. The increasing encroachment on the natural habitat has resulted in the decimation and even near extinction of some species. Along with this development, the basic concept in many modern zoos has changed from one of merely display to self-perpetuating units. Primate research facilities are orienting their research programs towards reproductive physiology and behavior in an effort to provide basic knowledge of reproduction in these species. This increased emphasis in the area of reproductive biology and the various efforts to improve breeding of these mostly endangered primates in captivity has stimulated the author to write this review. It represents an attempt to provide the reader with basic background information relating to the endocrinology and behavior of reproduction in the clawed New World monkeys as it exists at the time of publication. The intermediate evolutionary position ofCallimico goeldii between the clawed New World monkeys and the ‘true New World monkeys’ and our relatively poor knowledge about reproduction and behavior in this particular species fully justifies the focus on Goeldi’s monkey in this essay. This review is an attempt to provide a brief history of previous studies but also the basis for research in the future. The current status of knowledge of the small-bodied clawed monkeys is also discussed in an evolutionary context, with an emphasis on the different reproductive strategies in this dynamic group of primates. The outcome, not surprisingly, confirms the unique position ofCallimico goeldii in its social, ecological, and evolutionary environment.     

Late Quaternary pollen records from the middle Caquetá river basin in central Colombian Amazon

Three pollen records are presented from the Pantano de Monica region (0°42′S, 72°04′W, 160 m elevation) on the lower terrace of Rio Caquetá of the central Colombian Amazonas. Ten radiocarbon dates from three cores indicate that the deposits are of Holocene age, but the pollen data suggest that the record may also contain the Late Glacial. The core Pantano de Monica 1 covers the time interval from 11,150 BP (extrapolated) to 4730 BP. During the Late Glacial and early Holocene this swamp was smaller in size and waters were more shallow than today, with abundant Mauritia palm trees. This indicates that the lower terrace of the Caquetá River was better drained than today, which might be related to changes in the drainage system and/or drier conditions during that time. Late Glacial and early Holocene vegetational changes in the rain forests surrounding the swamp Pantano de Monica indicate successional stages, probably related to changes in the drainage system and/or climate changes. Presence of Podocarpus pollen grains up to 2.6% of the total sum (and influx of 78 grains cm⁻² yr⁻¹) point to the regional presence of Podocarpus at the beginning of the Holocene. Evidence of Podocarpus during glacial times in other pollen records from the Amazon basin has been taken as indicative of cooling. Core Pantano de Monica 2 was taken in a small swamp (1000 m distance to Pantano de Monica 1) and starts at 4000 BP when this location was well drained. Several changes in the composition of the rain forest are documented, such as increase in disturbance (increase of Cecropia) followed by a quick recovery (increase of Psychotria). Protium and Caryocar tree taxa were frequent, suggesting that the lower terrace area was well drained until 3080 BP, after which small swamps developed. Core Pantano de Monica 3 is from the wet forest in between the two swamps and represents the period since 3260 BP. Pollen data show a continuously increasing presence of palms, probably Euterpe, suggesting either a transition from well-drained to less drained conditions in the lower terrace during the late Holocene, and/or a more intensive human impact of the rain forest on the lower terraces of Rio Caquetá. The three records from the lower terrace of Rio Caquetá show different forest compositions in the past and indicate that the rain forest environments were not stable during Late Glacial and Holocene times. Comparison with other data from lowland records of northwestern South America suggest that climate change is a major factor for environmental change in central Colombian Amazon.     

Glutathione metabolism in primate lenses: A phylogenetic study of glutathione synthesis and glutathione redox cycle enzyme activities

Lens wet weights, soluble protein, and activities of γ-glutiamylcysteine synthetase, glutathione synthetase, glutathione peroxidase, and glutathione reductase were determined in primate lenses. The primary sources of lenses were middle-aged adult animals. The Primates, from 23 genera, were categorized into six superfamilies: hominoids (five species), Old World monkeys (seven species), New World monkeys (five species), tarsiers (two species), lemurs (six species), and lorisids (three species). Significant differences between various groups or combinations of groups were noted for γ-glutamylcysteine synthetase, glutathione peroxidase, and glutathione reductase activities. Lenticular γ-glutamylcysteine synthetase activity was very low in the Old World simian lenses and highest in the prosimians. Glutathione peroxidase activity was extraordinarily high in lenses of Old World monkeys. Glutathione reductase activity was low in all the prosimians but tenfold higher in hominoid lenses with intermediate values in monkeys of both the Old World and New World. Glutathione synthetase activity was variable, and no clear pattern which might be useful for primate classification was noted. Lenticular activity ratios of glutathione synthetase:γ-glutamylcysteine synthetase were highest in the Old World simians and lowest in the prosimians. These data with emphasis upon Aotus and the tarsiers were examined with regard to phylogenetic relationships. © 1994 Wiley-Liss, Inc.     

Survey of Nonhuman Primates for Antibodies Reactive With Epstein-Barr Virus (EBV) Antigens and Susceptibility of Their Lymphocytes for Immortalization With EBV

The susceptibility to transformation with Epstein-Barr virus (EBV) and the prevalence of antibodies reactive to EBV were examined in 43 primate species. In vitro EBV infection was revealed in lymphocytes from Old World monkeys, including patas monkeys and the colobines, as well as in lymphocytes from the apes. Antibodies reactive to EBV-early antigen/viral capsid antigen (EA/VCA) were detected in all the species of Old World monkeys and apes examined and in two out of seven species of New World monkeys.     

Importance of feeding strategies on the long-term success of fish invasions

This study assessed the feeding strategies of nine fish species in their native (Cuiabá River) and in an invaded basin (upper Paraná River) to identify trophic variables that may explain the success of these species in the new basin, over 30 years. The following predictions were analyzed: (i) species that display omnivorous or piscivorous diets in the native basin are favored in the invasion process over the long term, and (ii) specialist feeders are favored in the invasion process provided that their food items are highly available in the invaded area. These predictions were supported by the data; the species that were successful invaders had high trophic plasticity (omnivores), consumed a wide variety of food items from specific trophic guilds (piscivores), or if a species had a specialized diet, the resources demanded are abundant (detritivores). Thus, in a long-term perspective, the food resources used by these species are rarely limiting in aquatic ecosystems, and these feeding characteristics should be one of the key factors determining the colonization success of fishes. Understanding the factors that determine the success of invasive species in new areas is critical for developing management policies aimed at minimizing the impacts of biological invasions.