Navegando por Assunto "Primata"

Agora exibindo 1 - 20 de 45

Acesso aberto (Open Access)
Aspectos da ecologia do Cuxiú de Uta Hick, Chiropotes Utahickae (Hershkovitz, 1985), com ênfase na exploração alimentar de espécies arbóreas da ilha de germoplasma, Tucuruí-PA
(Universidade Federal do Pará, 2005-03-14) VIEIRA, Tatiana Martins; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
In 1985, construction of the Tucurui hydroelectric power station flooded 2400 km² of forest, creating hundreds of different sizes, fragmenting the populations of many organisms, including bearded sakis (Chiropoies spp.). The present study took place on the 129-ha Germoplasma island, which is home to a group of Chiropotes utahickae, which currently contains 23 members, studied previously by Santos (2002). The present study aimed primarily to describe certain aspect of the ecology of Uta Hick's bearded saki and to characterize the dietary exploitation of tree species. Data collection was based on monthly samples of eight days, with basic behavioural data being collected in one-minute scan samples at five-minute intervals, supplemented alternately by focal-tree and focal-fruit sampling. The principal behavioural categories were feed, travel, forage, rest and social interaction (containing several subcategories). A total of 11,277 scan sample records were collected, together with 259 focal tree samples, and 711 focal fruit samples, between March and August 2004. Overall, 50.6% of activity time was devoted to locomotion, 31.9% to feeding, 10.6% to rest, 5.4% to foraging activities, and 1.2% to social interactions. The diet consisted primarily of immature seeds (31.7%), immature mesocarp (21.2%), ripe fruit (18.3%), and flowers (14.4%). Comparisons with the results of Santos (2002) indicate a number of seasonal or longitudinal differences. The sakis exploited fruit of 0.4 to 15.3 cm in length, with seeds of between 0.1 cm and 2.3 cm. The sakis were considered to be seed predators for 74.2% of the 31 species analysed, although no significant relationship was found between predation and seed size. Also, no systematic relationship was found between the distance seeds were transported and their size, suggesting the influence of other factors, such as crown dimensions and feeding party size. Twenty years after isolation, the Germoplasma sakis appear to present typical Chiropotes behaviour patterns. Tolerance of habitat fragmentation appears to be supported by the exploitation of specific resources, such as the immature mesocarp of Inga spp. during a period of resource scarcity, and the consumption of Brazil-nut (Bertholletia excelsa) flowers. Flowers appear to be an especially important resource for the sakis of the Tucuruí reservoir (Santos, 2002; Silva, 2003). The present study constitutes an important contribution to the understanding of the species' s ecology, although it is clear that the Tucurui populations require further monitoring in order to provide more detailed information on diet, social organization, and animal-plant interactions, necessary for the development of sound conservation and management strategies.
Acesso aberto (Open Access)
Associação de emissões vocais de macacos-prego (Cebus apella, Primate, Cebidae) a contextos comportamentais em cativeiro
(Universidade Federal do Pará, 2008) MARQUES, Karoline Luiza Sarges; SILVA, Maria Luisa da; http://lattes.cnpq.br/2101884291102108; GALVÃO, Olavo de Faria; http://lattes.cnpq.br/7483948147827075
The vocalization is an important form of communication in primates, because the majority of the species lives in dense forests, what makes difficult visual communication at a distance. The Cebus apella species presents a rich vocal repertoire contextualized to diverse behaviors, as feeding, foraging, predators avoidance, contact, copulation, and others. Aiming to elaborate a vocalization data base of sixteen Cebus apella captive subjects, we collected, at the Experimental School for Primates biotery of Federal University of Pará, vocalizations emitted in natural occurrences (agonism, contact) and in designed experiments (individual meal and alarm). The vocalizations were recorded, edited, and the sonograms were made and analysed. At least ten distinct vocal emissions, grouped in different contexts (feeding, alarm, agonism and contact) and the behaviors without vocalizations were mapped. Our data confirmed that Cebus apella species, own an extensive vocal repertoire, with different calls associated to particular behaviors, exhibit sexual differences in calls and sound unity combinations, in agreement with indications of the cerebral plasticity and the social complexity of the species.
Acesso aberto (Open Access)
Avaliação seriada do perfil hematológico e bioquímico de primatas não humanos da espécie Sapajus apella tratados com lde-oleato de paclitaxel como instrumento para a terapêutica do câncer
(Universidade Federal do Pará, 2017-02-23) OLIVEIRA, Nayara Cristina Lima de; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099
Study of a chemotherapy delivery system, called LDE, with lipid composition similar to the natural low density lipoproteins of the body, denominated by the acronym LDL. LDEs have advantages over commercial chemical forms, since it is able to concentrate in the neoplastic tissues after injection into the circulatory chain, thus being able to target the tumors. LDE can be used as a "carrier" of paclitaxel (PTX) for possible reduction of toxicity and increase of its therapeutic action. The use of non-human primates as in vivo experimental models are of great importance in human health applications due to their anatomical, biochemical and phylogenetic similarities with human primates, generating results that can be interpreted more closely and safely to The phenomena in humans. The aim of the project was to evaluate the chronic toxicity of nanoparticles associated with to chemotherapy Paclitaxel (LDE-PTX) in individuals of the Sapajus apella species, based on the determination of hematological and biochemical parameters and their possible alterations. During the research 15 animals were used, divided into groups: Negative control (CN); Experimental (EXP1 and EXP2) where the animals received LDE-PTX intravenously two different doses of 175 mg / m2 and 250 mg / m2 respectively; and positive control (CP1 and CP2) where the animals intravenously received the drug in commercial form at the same doses used in the experimental group, respectively. Primates were accompanied for 6 cycles of chemotherapy, with interval of 3 weeks. Hematological and biochemical analysis was performed at each cycle through erythrogram and leukogram, alkaline phosphatase, total protein, albumin and globulin, total bilirubin and fractions, glycemia, amylase and serum lipase. E of the sodium and potassium eletrolytes were carried out in the serum of the animals during the collection days. Data were expressed as mean ± standard deviation and submitted to analysis of variance ANOVA, with Bonferroni post-test with significance for p <0.05, through BioEstat®5.3. The obtained results demonstrated advantages of the use of LDE-PTX, since the hematological tests demonstrate that there was a lower toxicity in all the chemotherapeutic cycles and the non-alteration of the majority of the biochemical parameters, demonstrate that the toxicity of the tested drug associated to LDE present smaller Effect toxic than its commercial version. It was concluded from the analysis of the results that hematological and biochemical toxicity was lower in treatment with PTX associated with LDE than treatment of PTX in its commercial form.
Acesso aberto (Open Access)
Caracterização e dinâmica espacial da caça de primatas em comunidades ribeirinhas da Amazônia Central
(Universidade Federal do Pará, 2015) PEREIRA, Priscila Maria; VALSECCHI, João; http://lattes.cnpq.br/8353254163114394; QUEIROZ, Helder Lima de; http://lattes.cnpq.br/3131281054700225
Acesso aberto (Open Access)
O coatá-de-testa-branca (Ateles marginatus) do baixo Rio Tapajós, Pará: distribuição, abundância e conservação
(Universidade Federal do Pará, 2001-02-16) RAVETTA, André Luís; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
The white-fronted spider monkey, Ateles marginatus, is an endangered species according to IUCN. Endemic to Brazilian Amazonia, its status is due to a combination of a relatively restricted geogaphic distribution and the growing human presence within this area. The present study focussed on the BR-163 (Santarém-Cuiabá) highway, on the right bank of the lower Rio Tapajós, a region of prolonged and intense human occupation. The principal aim of the present study was an evaluation of the distribution and abundance of A. marginatus within this area, and analysis of the factors determining these variables. Residents were interviewed informally at 16 sites in order to confirm the presence or absence of the species. Line transect population surveys were conducted at eight sites, representing differing degrees of habitat fragmentation, with a total transect length of 697.6 km. Groups of A. marginatus were monitored at two sites for the collection of data on their behaviour and ecology. The results indicate that the species is absent from some areas, including natural lacunae in its distribution as well as a zone of local extinction, that appears to extend as least as far as 60 km south of the city of Santarém. A total of 23 species of nonflying mammals were recorded in the population surveys, but the presence of A. marginatus was confirmed at only three sites. The study indicates that isolated fragments of forest of less than one hundred hectares are unable to support populations of A. marginatus. In the case of larger fragments, the presence and abundance of the species appears to be influenced more directly by human factors (hunting and logging). The species seems to be relatively rare even in continuous forest, which is similar to other populations of Ateles in Brazilian Amazonia. Two groups, one with eight members and the other with at least twenty, were identified during monitoring. As in other members of the genus, the formation of subgroups (fission-fusion), a relatively high proportion of females in the population and a frugivorous diet are also observed in A. marginatus. The study reveals the critical situation of the species in the region, in the face of human occupation, and the urgent need both to deter the process of habitat fragmentation and establish new protected areas.
Acesso aberto (Open Access)
Comparação de dois procedimentos computadorizados para avaliação de discriminação de cores em Cebus sp
(Universidade Federal do Pará, 2009-11) MAKIAMA, Sheila Tetsume; GOULART, Paulo Roney Kilpp; http://lattes.cnpq.br/7800966999068746; GALVÃO, Olavo de Faria; http://lattes.cnpq.br/7483948147827075
Color vision consists in discrimination of objects based on their spectral composition, assisting in the organism-environment interaction. Among primates, it is estimated that the majority of the platyrrhines monkeys has a polymorphic and sex-linked dichromacy. The objective of this study was to compare the results produced by different equipments and softwares for assessment of tri/dichromatic conditions of two males and two females of the genus Cebus sp. Two computerized programs were used: one involving an adapted version of the Cambridge Colour Test and another one developed for a standard computational system. In Experiment 1 and 2 were possible to verify the trichromatic condition of one female subject and the dichromatic condition of the rest of the participants. In Experiment 3, a female and a male subject presented a dichromatic performance compatible to that one registered in previous experiments. In this Experiment, a female participant presented a trichromatic performance compatible to that one registered in previous experiments. It was concluded that favorable conditions for assessment of color vision in platyrrhines species can be built involving equipment and software with low financial cost and easy to program. However, due the few number of sessions with the low financial cost equipment, it is suggested the replication of the Experiment 3 and more sessions should be made with more subjects and involving new stimuli arrangement. It is believed that, if new data confirm the data produced here, this equipment and procedure can be used for evaluation of others platyrrhines species where behavioral data are scarce.
Acesso aberto (Open Access)
A comparative study of eleven protein systems in tamarins, genus Saguinus (Platyrrhini, Callitrichinae)
(1997-03) MEIRELES, Carla Maria Marques; SAMPAIO, Maria Iracilda da Cunha; SCHNEIDER, Horacio; FERRARI, Stephen Francis; COIMBRA-FILHO, Adelmar Faria; PISSINATTI, Alcides; SCHNEIDER, Maria Paula Cruz
The genetic variability of six tamarin taxa, genus Saguinus, was analyzed comparatively using protein data from eleven systems coded by 15 loci. S. fuscicollis weddelli and S. midas midas were the most polymorphic taxa, and S. bicolor the least. The results of the phylogenetic analyses (UPGMA and neighbor-joining) and the genetic distances between taxa were generally consistent with their geographic and probable phylogenetic relationships. Analyses of the S. bicolor and S. midas populations suggested that they represent no more than three subspecies of a single species, S. midas, with the bicolor forms belonging to a single subspecies, S. midas bicolor. If supported by additional studies, this would have important implications for the conservation of the bicolor form, which is endangered with extinction. The genetic similarity of S. fuscicollis and S. mystax was also consistent with their geographical and morphological proximity, although more data from a larger number of taxa will be required before the taxonomic relationships within the genus can be defined.
Acesso aberto (Open Access)
Comparison of two computerized procedures for the assessment of color discrimination in Cebus apella
(2011-12) MAKIAMA, Sheila Tetsume; GOULART, Paulo Roney Kilpp; GALVÃO, Olavo de Faria
Color vision consists of the discrimination of objects based on their spectral composition. Among primates, the majority of Platyrrhini monkeys are estimated to have polymorphic and sex-linked dichromacy. The objective of this study was to compare the results produced by different equipment and software for the assessment of tri- and dichromatic conditions in one male and two female Cebus apella. Three experiments were programmed. In Experiment 1, verifying the trichromatic condition of one female subject and dichromatic condition of the remainder of the subjects was possible using an adapted version of the Cambridge Colour Test. Experiment 2 confirmed the results of Experiment 1 using a different array of stimuli of the same test. Experiment 3, which produced results similar to Experiment 2, consisted of a test developed for a standard computer system using stimuli with color properties similar to the ones used in the previous experiment. Favorable conditions for the assessment of color vision in Platyrrhini can be built with low-cost equipment and software. Once data have been gathered with additional subjects and new stimulus arrangements have been tested and confirmed, the procedure can be used for the evaluation of other Platyrrhini species for which behavioral color discrimination data are currently lacking.
Acesso aberto (Open Access)
Comportamento alimentar do Cuxiú-Preto (Chiroptes Satanas) na área de influência do Reservatório da Usina Hidrelétrica de Tucuruí-Pará
(Universidade Federal do Pará, 2003-03-21) SILVA, Suleima do Socorro Bastos da; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
Constructed in 1985, the Tucuruí hydroelectric power station created a 2430 lun2 lake (3°43'-5°15’S, 49°12'-50°00'W), and restricted populations of the southem bearded saki (Chiropotes satanas), an endangered primate, to a series of islands and other habitat fragments. This study took place at two sites on the lake's right bank, one in continuous forest (T4) and the other on a small island of 16.3 hectares (Su), with groups of 34 and seven sakis, respectively. The principal objective was an evaluation of the influence of habitat fragmentation on the sakis' foraging behaviour. Basic data were collected in one-minute scan samples with a five-minute interval, whereas foraging behaviour was recorded in greater detail in focal-tree samples, and behavioural sampling. Basic behavioural categories were locomotion, rest, forage, feed, and social interaction, with a number of subcategories. Between July and December 2002, 3503 scan records were obtained for group T4, and 835 for group Su. 'The activity budget of T4 was 55.8% locomotion, 21.7% feed, 16.1% rest, 3.6% forage, and 2.8% social interactions. Feeding was recorded at a similar proportion (22.4%) for Su, although this group spent significantly less time in locomotion (45.9%), and more at rest (27.0%). A major difference was also found in the number of plant species exploited for the dietary resources, 40 for T4 (Arecaceae being the most important family) but only 22 for Su (Lecythidaceae), although no significant difference was found in the diversity of their diets. The composition of their diets was significantly different, however, the major item for T4 was immature seeds (the mesocarp of palm fruits was also important), whereas the consumption of flowers — practically all from the species Alexa grandiflora (Leguminosae) — was very frequent in Su. The differences between groups seem to be at least partly related to that in their home ranges, which was 68.9 hectares for T4 and only 16.3 ha (the whole island) for Su. Aspects of the behaviour of group Su members, such as increased rest and feeding on flowers, may reflect the effects of habitat fragmentation on their ecology, with negative implications for the group's long term survival. It is hoped that these results will make a significant contribution to the development of effective conservation strategies at this endangered primata as well in the fragmented landscape of eastern Amazonia.
Acesso aberto (Open Access)
Comportamento e dieta de Chiropotes albinasus (I. Geoffroy & Deville, 1848) - cuxiú-de-nariz-vermelho
(Universidade Federal do Pará, 2013) SILVA, Rafaela Fátima Soares da; PERES, Carlos Augusto; http://lattes.cnpq.br/9267735737569372; VEIGA, Liza Maria; http://lattes.cnpq.br/4423233175920315
The red-nosed cuxiú, Chiropotes albinasus, is a poorly understood neotropical primate that is listed at ‘Threatened with Extinction’ by the IUCN. The current study was conducted on a group of C. albinasus at RPPN Cristalino, MT, Brazil. Activity budget, use of space and feeding ecology were studied using Simultaneous Scan methods. The study group was monitored for six months (two months in the rainy season, four in the dry season). The behavioural categories Moving, Feeing and Paused accounted for 81.17% of the activity records. Most activity was recorded in the middle strata of the forest (between 16 and 20m). Diet was principally frugivorous (82.52%), but invertebrates were also eaten. Representatives from some 18 plant families were consumed. Arrabidaea spp. and Brosimum latescens were the taxa most commonly consumed. During the dry season there was an increase in the consumption of such nonfruit items as invertebrates and flowers. Group size varied between 1 and 19 throughout the study. The sex-ration of groups also varied greatly. Parental care was observed by male C. albinasus, as well as interspeciic agonistic interactions between the cuxius and Ateles marginatus and between Sapajus apella.
Acesso aberto (Open Access)
Comportamento e dieta de um grupo de macacos-aranha-da-cara-branca, Ateles marginatus (É. Geoffroy, 1809), no sul da Amazônia
(Universidade Federal do Pará, 2014-12-17) SOARES, Paola Cardias; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627
The distribution of precipitation over the months, influences on annual distribution of food resources and how these resources can be found in an environment causes primates to adopt different strategies in order to gain access to them. In our study, we evaluated the variations in behavior and diet of the white whiskered spider monkey (Ateles marginatus) at the Cristalino Private Reserve. The primates were followed and behavioral and diet data was systematically collected over nine months, between September 2011 until May 2012, through the scan sampling method. The variation concerning activity budget, use of space and diet was analyzed for three periods characterized by distinct rainfall amounts (early rains, rainfall peak and transition from rain to drought). At the peak of the rains, the primates apparently maximized its energy consumption, moving more (43.8%) so as to have more access to fruits, which were probably more available in the environment, eating more fruits (96.5%) and resting less (18.5%). Upper height classes (>20 to 30 meters) were most widely used during periods of rain, both at the beginning and in the peak, at least in part as a way to shelter from the rain and the ranging area and daily journey lengths were higher at the early rains period. There was a predominance of females in the subgroups, with males being more recorded (36.2%) at the beginning of the rainy season, probably to copulate, an activity that had most of their records occurring in one month (December) for that same period. Largest subgroups were recorded during periods of increased precipitation, and smaller sub-groups in drier times seem to be part of the strategy to avoid intraspecific competition. The diet was mostly frugivorous, being distinguished in the transition from rain to drought, not only by the lower contribution of ripe fruits (54.3%) as well as the contribution of young leaves (35.8%), when compared to the other two periods, when ripe fruits composed more than 70% of the diet. Diet diversity of ripe fruit was concentrated in a small number of key species of fruit trees and the fruits used to be swallowed whole, with the disposal of seed being unusual and occurring only for few species. Seeds ingested passed intact by the digestive tract of spider monkeys and caterpillars’ consumption was limited to a short period of time, constituting an alternative source of protein. Alternative items like decaying wood and earth from termite nests in months of low rainfall seem to complement the diet at the same time that also supply the primates’ diet with nutrients such as sodium, calcium and phosphorous, which are less present in ripe fruits, and the consumption of Eichhornia sp., although little recorded, suggests that these aquatic plants are important nutritional content in the diet of these primates. High frugivory of spider monkeys and their ability to disperse intact seeds away from the parent plants, reinforce its importance in the regeneration of forests and justify their conservation and their habitats. Information regarding the behavioral ecology and diet of these primates, though basic, are pioneering and essential to understand the adaptive strategies of the species.
Acesso aberto (Open Access)
Cytogenetic study of the genus Saguinus (Callithrichidae, Primates)
(1997-12) DANTAS, Sandra Maria Mendes de Moura; BARROS, Regina Maria de Souza
Eight subspecies from the genus Saguinus (S. fuscicollis fuscicollis, S. fuscicollis weddelli, S. bicolor bicolor, S. bicolor martinsi, S. mystax mystax, S. imperator imperator, S. midas midas, and S. midas niger) were studied. Five of them (S. f. fuscicollis, S. f. weddelli, S. b. martinsi, S. m. mystax and S. i. imperator) had their karyotypes described for the first time. Conventional coloration, banding patterns G, C and NOR, and G/C sequential banding tecniques were used. All samples showed the same diploid number (2n = 46). The patterns of the G, C and NOR bands were very similar with little differences in the quantity and constitutive heterochromatin distribution of the autosomes. Constitutive heterochromatin was observed only in telomeric regions of some chromosomes of S. f. fuscicollis and S. f. weddelli. The X chromosome was the same in all subspecies, but chromosome Y differed in size and morphology. XX/XY chimerism was verified in all subspecies.
Acesso aberto (Open Access)
Desenvolvimento comportamental manipulativo e ocorrência de olhar mútuo entre macacos-prego (Cebus cf. apella) em cativeiro
(Universidade Federal do Pará, 2011-11-07) JACOMETTO, Ingrid Schunlaus Nikolak; GALVÃO, Olavo de Faria; http://lattes.cnpq.br/7483948147827075
During the first two months of life the offspring of Cebus depend almost exclusively on their mother. Only after the third month the newborn starts to move around independently, and at that time major changes in their behaviors pattern occur, along with an increase in the manipulative repertoire. The objectives of this study are to monitor the development of manipulative behavior in three Cebus cf. apella newborns, and check the possible occurrence of mutual gaze between monkeys. In Experiment 1, using the focal animal sampling, it was observed the baseline frequency of the behavioral categories of manipulative behavior of three Cebus cf. apella newborns. Following, four types of objects were inserted in the cage, one every week. Experiment 2 was a simple discrimination test between pictures of faces with direct versus desviated gaze. Experiment 3 was a simple discrimination training, between two stimulus pairs: front faces with direct versus deviated gaze, and front face versus profile face. The results show that newborns of the same age group spent about the same time manipulating objects. It was not possible to observe a clear pattern of preference for direct or deviated gaze in Experiment 2. Subjects were able to discriminate gaze direction (Experiment 3).
Acesso aberto (Open Access)
Desenvolvimento do dimorfismo sexual em espécies de macacos-prego, gênero Cebus Erxleben, 1777 (Primates, Cebidae)
(Universidade Federal do Pará, 2008) MIRANDA, Cleuton Lima; SILVA JÚNIOR, José de Sousa e; http://lattes.cnpq.br/4998536658557008
The studies on sexual dimorphism available in the scientific literature have shown that Cebus apella is the most dimorphic species within the genus Cebus. However, it is worthy to say that several species of Cebus currently recognized were previously considered subspecies of C. apella, and were grouped as one single species in the studies mentioned above. This is not the case for the present report, in which I recognize six species previously assigned to C. apella. Additionally, most studies on sexual dimorphism in Cebus were based only on adult specimens, assuming that individuals exhibit no more growth after reaching complete permanent dentition. The lack of studies that take into account young or subadult specimens may result in a deficient knowledge about the origins of sexual dimorphism, because different ontogenetic processes may be related to the development of sexual dimorphism, all of them leading to similar results in adult specimens. Considering the issues mentioned above, the aims of the present study are to assess the sexual dimorphism in the skull and in the development degree of head tufts through different ontogenetic stages in six capuchin monkey species, all of them assigned to the subgenus Sapajus (Cebus apella, C. macrocephalus, C. libidinosus, C. cay, C. nigritus e C. robustus), and to evaluate the existence of taxonomic variation in the development and the amount of sexual dimorphism found. I examined 774 specimens housed in Brazilian institutions. I measured 20 cranial variables, examined 12 qualitative cranial characters, and established four character states for the development degree of the head tufts. I used the Student t Test with Bonferroni adjustment to evaluate the sexual dimorphism, and the Principal Component Analysis (PCA) followed by the Discriminant Analysis (DA) to test the statistical significance among the age classes herein recognized (infants, juveniles, subadults, and adults; the latter group was divided in AD1 and AD2 in C. apella). The results show that sexual differences in the skull of species of Sapajus can be found in subadult specimens (ca. 3.5 years old), of which the most conspicuous is the length of the upper canine. In this life stage, the sexual differences are not statistically significant. In adult specimens (ca. 5 years old), most cranial variables showed significant sexual dimorphism. The number and composition of the dimorphic variables varied among the different species included in this study. The species with more dimorphic variables were C. apella and C. robustus (N=15), followed by C. nigritus (N=13), C. libidinosus (N=10), C. cay (N=7), and C. macrocephalus (N=3). Different from previous studies available in the scientific literature, which states that sexual dimorphism in the skull of Cebus (Sapajus) arises in young specimens (ca. 27 months old), my results showed that a significant sexual dimorphism in this subgenus appears only in adult specimens. My results suggest that the heterocronic process of the hipermorphose rate is the main cause of the sexual dimorphism pattern exhibited by Sapajus. The species of capuchin monkeys included in this study exhibited different degree of development in the head tufts. In general, the development degree of this character in Cebus (Sapajus) is related to the age class to which the specimen belongs. Moreover, there is no sexual dimorphism in this character in C. cay, C. robustus, and C. nigritus. By contrast, female specimens of C. libidinosus appear to exhibit more developed head tuft than male specimens. Finally, my results suggest that the species of capuchin monkeys analyzed herein may have experienced different kinds or intensities of selective pressure relative to sexual dimorphism during their evolutionary history.
Acesso aberto (Open Access)
Desenvolvimento do dimorfismo sexual nos macacos-de-cheiro (Saimiri VOIGT, 1831)
(Universidade Federal do Pará, 2005) MUNIZ, Izaura da Conceição Magalhães; SILVA JÚNIOR, José de Sousa e; http://lattes.cnpq.br/4998536658557008
The squirrel monkeys Saimiri Voigt, 1831 are arboreal and agile primates with a relatively small body as compared to other New World primates. The species are distributed in the Amazon and part of Central America. Several investigations were contucted in order to stablish the taxonomic groups in Saimiri. However, the results of these investigations showed an amount of divergences as to the classification, taxon validity as well as the taxonomic status. In this genus, there are sexual differences with regard to the pattern of coloration of skin, size and form of canine teeth and in the annual spermatogenic cycle in males that characterises the fatted condition due to the deposition of subcutaneuos fat. During this period, the males present an increase in weight ranging from 15 to 20%. The present study aimed to analyse the sexual dimorfism in Saimiri sciureus, comparing the results with other five species of the genus Saimiri (S. cassiquiarensis, S. juruanus, S. ustus, S. boliviensis e S. vanzolinii). A total of 610 specimens were analysed from the collections of the Museu Paraense Emílio Goeldi (MPEG), Museu Nacional, Universidade Federal do Rio de Janeiro (MNRJ) and Museu de Zoologia da Universidade de São Paulo (MZUSP). The age classes were determined according to the morphology of the dental arch described on the basis of the eruptive sequence of deciduous and permanent teeth. Data on chromatic characteristics were collected to analyse the preauricular patch of females in relation to the process of dental eruption, cranial morphology to verify the sexual and age differentiation. In addition, twenty one cranial measurements were perfomed using the Student t-test. There were no differences in the coloration of the skin among the sexual classes up to the adult age in any sexes. There were no differences in the coloration of the skin among the age classes in males. The blackish preauricular patch is an exclusive trait of adult females, however it is not related to ontogeny. The beginning of the sexual dichromatism of the skin is not associated with the rising of dimorfism in cranial morphology, specially of teeth. Macroscopic sexual differences such as size and morphology of cranium, morphology of face, bizygomatic distance and morphology of jaw could be observed from the subadult age. The findings indicated that the sexual dimorfism for the species analysed is better observed in the variables related to the mastigatory apparatus. Moreover, sexual differences in the mophology of cranial bones could be clearly identified among subadult individuals of any taxon. The males were bigger than females from the subadult age onwards and the most conspicuous characteristic of the sexual dimorfism is the cranium length. The species differ from each other because they presented an exclusive or a group of morphometric variables demonstrating the sexual dimorfism.
Acesso aberto (Open Access)
Dimorfismo sexual em espécies de macacos-aranha, gênero Ateles É. Geoffroy, 1806 (Atelidae), com distribuição amazônica
(Universidade Federal do Pará, 2008) MONTEIRO, Dijane Pantoja; SILVA JÚNIOR, José de Sousa e; http://lattes.cnpq.br/4998536658557008
The study of the secondary sexual differences in spider monkeys (Ateles É. Geoffroy gender, 1806) has shown controversial results, mainly concerning the body weight. Results range from positively dimorphic, where males are larger than females, to negatively dimorphic, with females larger than males. However, it is known that the group presents the lowest degree of dimorphism amongst the Atelid species. Considering that sexual differences related to body mass directly influence on the skull measurements of the individual, comparisons have been made from 25 skull measurements and 03 body measurements from three species of primates of the Ateles gender with Amazon distribution, A. paniscus, A. marginatus and A. chamek. Samples of adults from three Brazilian museums were used. There were not samples enough from species A. belzebuth for the performance of the analysis. Besides the morphometric analyses, it was performed an age comparison as for the size of the white hair stripe on the face of the A. marginatus. Skull measurements have been compared between sexes through multi-varied analyses, (analysis of the main-ACP components and discriminator-AD analysis), whilst the measurements of the body and the frontal spot have been compared through the ANOVA. The A. marginatus species did not present sexual differences in the pattern of distributions of the white hair on the face, but it seems to be influenced by aging. For the measurements related to the body, only the species A. paniscus and A. marginatus presented samples enough to the performance of statistical analyses. For both species it was not observed differences between sexes, except as for the length of the tail of A. paniscus, which was negatively dimorphic. However, such a result may be the reflex of mistakes at the measurement of the individuals at the moment of data collecting. To the skull and jaw measurements, all species presented few dimorphic variables, but, as for the size of the canine tooth, the differences between males and females were highly significant. Other measurements which were recognized as dimorphic were those ones related to the masticator apparatus. Considering that these structures participate directly on the relationships of competition and hierarchy, the low degree of sexual dimorphism associated to the Ateles gender may be the result of its social system of the fission-fusion type. A comparison has been performed with literature data about chimpanzees that pursue the same system of social organization, but present more dimorphism. It was verified that differences of the foraging, organization and use of the habitat by the females may determine a differentiated growth of the males and, consequently, have influence in the degree of dimorphism presented by these species. In spite of being considered, in the present study, as a monomorphic group, the sexual differences in Ateles seem to be more evident at the sub-adult age. Hence, it is necessary an ontogenetic study that shall perform a better refining for the adult class in order to determine, approximately, in what period of the life cycle of these primates such a differentiation occurs and what ecological or behavioral factors may be associated to this characteristics.
Acesso aberto (Open Access)
Dispersão de sementes por sauins-de-coleira (Saguinus bicolor Spix, 1823; Primates:Cebidae): efeitos do padrão de deslocamento na formação de sombras de sementes
(Universidade Federal do Pará, 2012) LIMA, Roberto Guevara Ferreira; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627
Quantifying the seed shadow generated by a disperser, which is the way seeds are distributed as a function of both the time seeds are retained in its digestive tract and of its ranging patterns through the habitat, is a key step to assess the impact of the seed disperser on structuring and functioning of plant populations and communities. This is the first study concerning the primate S. bicolor as a seed disperser and aimed to investigate the formation pattern of seed shadow in relation to the ranging patterns of the species. The moving of four groups of S. bicolor was monitored in three forest fragments in Manaus, Central Amazonia. The position of the animals in a trail grid was registered at five minutes intervals over the whole period of activity for five days a month over at least 15 months each group. The seed retention time were estimated by records of the time of ingestion, defecation and number of seeds of five species of cultivated fruits offered to four captive tamarins. Seed shadows were estimated by combining ranging patterns data with the seed retention time data. To each group, mean dispersal distance and the proportion of the home range used were obtained on a monthly basis, and their relation was accessed by a simple linear regression. The seed retention time ranged from 27 to 295 minutes (N = 394), with more than half of the seeds being retained up to two hours in the gut, and average number of seeds per defecation was 3,5 (± 3,7; N = 111). Probabilities of seed dispersal out of the vicinity of the parent plant are greater than 80% besides including distances greater than 1 km. For only two groups was verified a relation between the proportion of home range used and the dispersal distance, on a monthly basis, and one of them the explanatory power of the model reached less than 20%. The results indicate that S. bicolor disperses seeds effectively and, like other callitrichines, may contribute to the structuring and regeneration of forest ecosystems.
Acesso aberto (Open Access)
Divergent evolution and purifying selection of the H (FUT1) gene in New World monkeys (Primates, Platyrrhini)
(2004) BORGES, Barbara do Nascimento; HARADA, Maria Lúcia
In the present study, the coding region of the H gene was sequenced and analyzed in fourteen genera of New World primates (Alouatta, Aotus, Ateles, Brachyteles, Cacajao, Callicebus, Callithrix, Cebus, Chiropotes, Lagothrix, Leontopithecus, Pithecia, Saguinus, and Saimiri), in order to investigate the evolution of the gene. The analyses revealed that this coding region contains 1,101 nucleotides, with the exception of Brachyteles, the callitrichines (Callithrix, Leontopithecus, and Saguinus) and one species of Callicebus (moloch), in which one codon was deleted. In the primates studied, the high GC content (63%), the nonrandom distribution of codons and the low evolution rate of the gene (0.513 substitutions/site/MA in the order Primates) suggest the action of a purifying type of selective pressure, confirmed by the Z-test. Our analyses did not identify mutations equivalent to those responsible for the H-deficient phenotypes found in humans, nor any other alteration that might explain the lack of expression of the gene in the erythrocytes of Neotropical monkeys. The phylogenetic trees obtained for the H gene and the distance matrix data suggest the occurrence of divergent evolution in the primates.
Acesso aberto (Open Access)
Diversidade de mamíferos e uso da fauna nas Reservas de Desenvolvimento Sustentável Mamirauá e Amanã - Amazonas - Brasil
(Universidade Federal do Pará, 2005) AMARAL, João Valsecchi do; SILVA JÚNIOR, José de Sousa e; http://lattes.cnpq.br/4998536658557008
The northern part of western Amazon in Brazil has had few studies related to the diversity of mammals, especially in the Içá-Japurá and Japurá-Negro rivers interfluves. This fauna, as well as birds and reptiles, has been constantly impacted by human led activities, like hunting. This study had two main objectives, to initiate a systematic survey of the diversity of mastofauna in different habitats of Mamirauá and Amanã Sustainable Development Reserves, and to investigate its patterns of use by local human population. An updated species list was created to cover the Iça-Japurá and Japurá-Negro rivers interfluves, as well as to each sample area. An analysis of hunting practices was made to determine íts impacts on the local fauna of mammals, bírds and reptiles and to generate subsidies to the elaboration of management plans for these protected arcas. To carry out this analysis, huntíng expeditions were monítored in six villages in Mamirauá Reserve and four in Amanã, during a period of two years. Two major field expeditions were made in both areas and the survey produced represents the first systematic investígation about the diversity of mammals in Amanã, which considered every order present in the region. In addition to that, the list of mastofauna produced for Mamirauá through this study added 25% more species than previous lists. It was identified 57 mammal species in Amanã and 40 in Mamirauá. Furtherrnore, the results already obtained have elucidated prior queries about a few mammal species present in these Reserves. Mammal diversity was central to the hunting patterns found during the study period. In Amanã typical Amazonian hunting patterns were encountered, that is, herbivore mammals and large and medium sized bírds were mostly hunted and represented the highest percentage of prey weight. The main huntíng pattern found in Mamirauá was the use of Chelonia, Prímates and Aves (medium and large sized). Finally, considerations were made about the establíshment of strategies toward the management of the cynergetic fauna in the areas under study, in order to contribute to a future sustainable model of wildlife use, one that takes in consideration biological, economical and cultural aspects in the region.
Acesso aberto (Open Access)
Ecologia alimentar de Saimiri sciureus cassiquiarensis (Lesson, 1840) (Primates, Cebidae) em florestas de várzea da Amazônia central brasileira
(Universidade Federal do Pará, 2014-02-12) ARAUJO, Michele; QUEIROZ, Helder Lima de; http://lattes.cnpq.br/3131281054700225