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1.
Am J Primatol ; 84(6): e23341, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34662461

RESUMO

Primates are affected by fluctuations in ambient temperatures, mostly through thermoregulatory costs and changes in the availability of food. In the present study, we investigate whether the ambient temperature and proxies of food availability affect the activity period of marmosets (Callithrix spp.). We predicted that: (i) at colder sites, marmosets would spend more time at sleeping sites; (ii) midday resting bouts would be longer at hotter sites; (iii) the onset/cessation of activity and resting behavior at midday would be more closely related to temperature than food availability, and (iv) highly exudativorous groups would have higher total levels of resting. We compiled data on the onset and cessation of activity and the time spent resting at midday from seven marmoset studies from sites with a wide range of temperatures. We used generalized linear mixed models to verify the relationship between the dependent variables (lag between dawn and the onset of activities, lag between cessation of activities and dusk, and proportion of resting during midday) and the minimum and maximum temperatures at the respective study sites, together with proxies of food availability (exudativory rates, the amount of habitat available per individual, and net primary productivity) using each sample month as a sampling unit and the identity of the study as a categorical random factor. At colder sites and during colder months, the marmosets left sleeping trees later in the morning and ceased their activities earlier, while at hotter sites and during hotter months, they spent more time resting during midday. More exudativorous groups become active later in the morning, but also ceased their activities later. The abundance of food did not affect the timing of activities. We provide evidence that both low and high temperatures affect marmosets' activities, and that their activity period appears to be more influenced by the thermal environment than food availability.


Assuntos
Callithrix , Ecossistema , Animais , Temperatura , Árvores
2.
Genet Mol Biol ; 41(3): 699-712, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30235394

RESUMO

Capuchin monkeys are currently represented by four species of Cebus and eight of Sapajus. This group is taxonomically complex and several questions still need to be clarified. In the current study, using mtDNA markers and a larger sample representation than in previous studies, we seek to understand the phylogenetic relationships among the capuchin lineages and their historical biogeography. All 12 species of capuchins were analyzed for the mitochondrial Control Region and Cytochrome b to test two biogeographical hypotheses: "Reinvasion of the Amazon (ROA)" and "Sympatric Evolution (SEV)". The phylogenetic relationships among distinct lineages within genera is consistent with an evolutionary diversification pattern probably resulting from an explosive process of diversification and dispersal between 2.0 Ma and 3.0 Ma. Also, the analyses show that the ancestral capuchins were distributed in a wide area encompassing the Amazon and Atlantic Forest. Our results support the SEV hypothesis, showing that the current syntopic distribution of Cebus and Sapajus can be explained by a sympatric speciation event in the Amazon. We also indicate that the recently proposed species taxonomy of Cebus is not supported, and that S. cay and S. macrocephalus are a junior synonym of S. apella.

3.
Am J Primatol ; 79(5)2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28103408

RESUMO

Conservation practices in the tropics often rely on the data available for a few, better-known species and the adoption of an appropriate spatial scale. By defining a set of landscape units that account for critical aspects of the focal species, the information available on these conservation targets can support regional conservation policies. Here, we define and classify adjacent landscapes, termed planning units, to orientate management decisions within and among these landscapes, which are occupied by an endangered flagship primate species (Coimbra-Filho's titi monkey, Callicebus coimbrai) from eastern Brazil. We use landscape boundaries (highways and river systems), and a high-resolution map of forest remnants to identify continuous and manageable landscapes. We employed functional landscape metrics based on the species' dispersal ability and home range size to characterize and classify these landscapes. We classified planning units by scoring them according to a suite of selected metrics through a Principal Component Analysis. We propose 31 planning units, containing one to six C. coimbrai populations, most with low values of habitat availability, functional connectivity and carrying capacity, and a high degree of degradation. Due to this poor landscape configuration, basic management practices are recommendable. However, additional aspects of the landscapes and the populations they contain (e.g., matrix type and genetic variability) should improve the scheme, which will require a closer integration of research aims with socio-political strategies. Even so, our scheme should prove useful for the combination of information on conservation targets (i.e., focal species) with management strategies on an administrative scale.


Assuntos
Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Pitheciidae , Animais , Brasil , Tomada de Decisões , Mapeamento Geográfico
4.
ScientificWorldJournal ; 2017: 8064126, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29359177

RESUMO

The exploitation of resources by closely related species with similar niches may be mediated by differences in activity patterns, which may vary in nycthemeral scale and seasonal scale. Piranhas Serrasalmus gibbus and Serrasalmus rhombeus are Neotropical predators that occur sympatrically in many environments of the Amazon basin. To evaluate the strategies adopted by these two species in a restricted environment (a reservoir), nycthemeral and seasonal samples were made, identifying the composition of the diet and their activity patterns. A total of 402 specimens were collected: 341 S. gibbus and 61 S. rhombeus. Both species fed themselves primarily on fish, with some seasonal variation being found in S. gibbus during the flood season, when plant material was consumed. There was considerable temporal overlap in the foraging behavior of the two species, although S. rhombeus presented a bimodal pattern of abundance over the 24-hour cycle. S. rhombeus was more active during the nighttime, between dusk and early morning, whereas S. gibbus was active throughout the nycthemeral cycle. These findings indicate low levels of competition between the two species, which allowed for a considerable overlap in nighttime foraging, following distinct nycthemeral patterns of foraging activity and allowing their coexistence.


Assuntos
Caraciformes/fisiologia , Comportamento Alimentar , Ciclos de Atividade , Animais , Caraciformes/classificação , Ecossistema , Comportamento Predatório
5.
Glob Chang Biol ; 22(6): 2003-12, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26663738

RESUMO

Land use changes have profound effects on populations of Neotropical primates, and ongoing climate change is expected to aggravate this scenario. The titi monkeys from eastern Brazil (Callicebus personatus group) have been particularly affected by this process, with four of the five species now allocated to threatened conservation status categories. Here, we estimate the changes in the distribution of these titi monkeys caused by changes in both climate and land use. We also use demographic-based, functional landscape metrics to assess the magnitude of the change in landscape conditions for the distribution predicted for each species. We built species distribution models (SDMs) based on maximum entropy for current and future conditions (2070), allowing for different global circulation models and contrasting scenarios of glasshouse gas concentrations. We refined the SDMs using a high-resolution map of habitat remnants. We then calculated habitat availability and connectivity based on home-range size and the dispersal limitations of the individual, in the context of a predicted loss of 10% of forest cover in the future. The landscape configuration is predicted to be degraded for all species, regardless of the climatic settings. This include reductions in the total cover of forest remnants, patch size and functional connectivity. As the landscape configuration should deteriorate severely in the future for all species, the prevention of further loss of populations will only be achieved through habitat restoration and reconnection to counteract the negative effects for these and several other co-occurring species.


Assuntos
Mudança Climática , Conservação dos Recursos Naturais , Ecossistema , Haplorrinos , Animais , Brasil , Previsões , Florestas , Modelos Biológicos
6.
Am J Primatol ; 78(5): 493-506, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26031411

RESUMO

Pitheciids are known for their frugivorous diets, but there has been no broad-scale comparison of fruit genera used by these primates that range across five geographic regions in South America. We compiled 31 fruit lists from data collected from 18 species (three Cacajao, six Callicebus, five Chiropotes, and four Pithecia) at 26 study sites in six countries. Together, these lists contained 455 plant genera from 96 families. We predicted that 1) closely related Chiropotes and Cacajao would demonstrate the greatest similarity in fruit lists; 2) pitheciids living in closer geographic proximity would have greater similarities in fruit lists; and 3) fruit genus richness would be lower in lists from forest fragments than continuous forests. Fruit genus richness was greatest for the composite Chiropotes list, even though Pithecia had the greatest overall sampling effort. We also found that the Callicebus composite fruit list had lower similarity scores in comparison with the composite food lists of the other three genera (both within and between geographic areas). Chiropotes and Pithecia showed strongest similarities in fruit lists, followed by sister taxa Chiropotes and Cacajao. Overall, pitheciids in closer proximity had more similarities in their fruit list, and this pattern was evident in the fruit lists for both Callicebus and Chiropotes. There was no difference in the number of fruit genera used by pitheciids in habitat fragments and continuous forest. Our findings demonstrate that pitheciids use a variety of fruit genera, but phylogenetic and geographic patterns in fruit use are not consistent across all pitheciid genera. This study represents the most extensive examination of pitheciid fruit consumption to date, but future research is needed to investigate the extent to which the trends in fruit genus richness noted here are attributable to habitat differences among study sites, differences in feeding ecology, or a combination of both.


Assuntos
Dieta/veterinária , Frutas/classificação , Herbivoria , Pitheciidae/fisiologia , Plantas/classificação , Animais , Ecossistema , Florestas , Geografia , Filogeografia
7.
ScientificWorldJournal ; 2016: 2810136, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27699201

RESUMO

Urbanization causes environmental impacts that threaten the health of aquatic communities and alter their recovery patterns. In this study, we evaluated the diversity of intertidal fish in six areas affected by urbanization (areas with native vegetation, deforested areas, and areas in process of restoration of vegetation) along an urban waterfront in the Amazon River. 20 species were identified, representing 17 genera, 14 families, and 8 orders. The different degrees of habitat degradation had a major effect on the composition of the fish fauna; the two least affected sectors were the only ones in that all 20 species were found. Eight species were recorded in the most degraded areas. The analysis revealed two well-defined groups, coinciding with the sectors in better ecological quality and degraded areas, respectively. The native vegetation has been identified as the crucial factor to the recovery and homeostasis of the studied ecosystem, justifying its legal protection and its use in the restoration and conservation of altered and threatened environments. These results reinforce the importance of maintaining the native vegetation as well as its restoration in order to benefit of the fish populations in intertidal zones impacted by alterations resulting from inadequate urbanization.


Assuntos
Recuperação e Remediação Ambiental , Peixes , Florestas , Urbanização , Animais , Brasil , Rios
8.
Zoolog Sci ; 32(1): 77-87, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25660700

RESUMO

This study reviews the data available on the distribution of three-banded armadillos of the genus Tolypeutes, identifying potential geographic barriers and evaluating possible biogeographic processes that may account for the present-day distribution of the species and its conservation status. The database was derived from published records, interviews, and voucher specimens, over a timescale ranging from the fossil record to specimens collected in 2013. A total of 236 localities were recorded, with 68 attributed to Tolypeutes matacus and 168 to Tolypeutes tricinctus. The vegetation within the range of the genus is predominantly a xerophytic mosaic of grassland, savannas, open woodland, and xeric thorn forest. The marine transgressions of the Miocene and the uplifting of the Brazilian Shield may have contributed to the vicariant separation of the ancestral populations of T. matacus, to the west and south, and T. tricinctus, to the north and east. The three-banded armadillo is possibly one of the most threatened of Brazilian mammals, considering the low number of recent records and the fact that it is hunted intensively throughout its range.


Assuntos
Distribuição Animal/fisiologia , Conservação dos Recursos Naturais/métodos , Xenarthra/fisiologia , Animais , América do Sul
9.
Am J Primatol ; 77(4): 425-33, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25407393

RESUMO

Understanding the effects of habitat structure and other environmental variables on the density of a species can help define its habitat preferences and key ecological determinants of population parameters. The present study evaluated the effects of fragment size, the presence of a key predator/competitor, the yellow-breasted capuchin (Sapajus xanthosternos), primary productivity, the abundance of bromeliads, and habitat structure on the population density of the common marmoset (Callithrix jacchus). A total of 21 fragments were surveyed within a 350-km long zone of coastal Atlantic Forest representing the southern extreme of the distribution of the species in the Brazilian Northeast. An index of marmoset density was generated for each site based on playback surveys. The relationship between the density of marmosets and a set of parameters was evaluated by multiple regression. A Principal Components Analysis (PCA) condensed the five variables of habitat structure into two principal components, which contained 85% of their combined variation. The model that best explained the density of marmosets (R(2) = 59.1) contained the second PCA component and the presence/absence of capuchins. The analysis indicated that the marmosets prefer forests with denser understory, whether or not they are secondary habitats. The negative effect of the presence of capuchins may be related to predation pressure. The results of this study indicate that multiple-site studies may provide important insights into the habitat preferences of primate species and the factors that affect their population density.


Assuntos
Callithrix , Cebinae , Animais , Brasil , Bromeliaceae , Ecossistema , Florestas , Densidade Demográfica , Comportamento Predatório , Análise de Componente Principal
10.
J Anim Ecol ; 83(6): 1523-30, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24773500

RESUMO

Geographic gradients in the species richness of non-human primates have traditionally been attributed to the variation in forest productivity (related to precipitation levels), although an all-inclusive, global-scale analysis has never been conducted. We perform a more comprehensive test on the role of precipitation and biomass production and propose an alternative hypothesis - the variation in vertical structure of forest habitats as measured by forest canopy height - in determining primate species richness on a global scale. Considering the potential causal relationships among precipitation, productivity and forest structure, we arranged these variables within a path framework to assess their direct and indirect associations with the pattern of primate species richness using structural equation modelling. The analysis also accounted for the influence of spatial autocorrelation in the relationships and assessed possible historical differences among biogeographical regions. The path coefficients indicate that forest canopy height (used as a proxy for vertical forest structure) is a better predictor of primate species richness than either precipitation or productivity on both global and continental scales. The only exception was Asia, where precipitation prevailed, albeit independently from productivity or forest structure. The influence of spatially structured processes varied markedly among biogeographical regions. Our results challenge the traditional rainfall-based viewpoint in favour of forest distribution and structure as primary drivers of primate species richness, which aggregate potential effects from both climatic factors and habitat complexity. These findings may support predictions of the impact of forest removal on primate species richness.


Assuntos
Distribuição Animal , Biodiversidade , Florestas , Primatas/fisiologia , Animais , Biomassa , Chuva , Análise Espacial
11.
Am J Primatol ; 76(4): 385-92, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24323495

RESUMO

Activity budgets are widely used in primate behavioral studies for the analysis of ecological strategies. In some cases, there is considerable seasonal variation in the length of the daily activity period. Here, activity budgets from two field studies of Callithrix flaviceps were compiled first by the traditional approach (proportion of scan sample records) and then by considering the proportion of time dedicated to each activity over the 24-hr cycle (adjusted budget). Both groups were almost invariably active for at least 1-2 hr less than the daylight period, with significantly shorter activity periods during the austral winter, when the daylight period was up to 2:35 hr shorter than in the summer. The adjustment of activity budgets provided a completely different perspective on foraging strategies. Whereas the basic budgets indicated a significant increase in foraging and moving during the resource-poor dry season (winter) months, the time-adjusted data revealed that the primary strategy was a time-minimizing one, with the animals simply spending more time at rest during the longer activity periods of summer days. While both groups followed the same pattern of relatively short activity periods, there were considerable differences between sites in the mean duration of the period in a given month, and in behavior patterns, although the analysis of the determining factors was beyond the scope of the present study. Overall, the results of the study indicate that the manipulation of the duration of the daily activity period may be an integral component of primate behavioral strategies, and that this parameter should be taken into account systematically when evaluating activity patterns, especially at sites at relatively high latitudes where day length may vary considerably over the course of the year.


Assuntos
Ciclos de Atividade , Callithrix/fisiologia , Comportamento Alimentar , Atividade Motora , Estações do Ano , Animais , Brasil , Observação , Projetos de Pesquisa
12.
Am J Primatol ; 75(4): 333-41, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23238956

RESUMO

The common marmoset (Callithrix jacchus) is amply distributed in the Brazilian Northeast, but little is known of its ecology in the semi-arid Caatinga scrublands. The present study provides the first detailed data on the composition of the diet of C. jacchus in Caatinga ecosystems, derived from observations at four sites in the state of Sergipe. While exudate sources were gouged at all four sites in a manner typical of the species, fruit was the principal component of the diet at the main study site during most months, and a number of unusual items were eaten, including leaves, and the reproductive parts of cacti and bromeliads. These plants are rarely recorded in marmoset diets, but are common in caatinga habitats. Leaves were ingested during 5 of the 8 months monitored at the main study site, reaching 39.74% of the diet in 1 month, and appeared to be an alternative fallback food to plant exudates during periods when fruit was scarce. Three species of cactus provided both flowers and fruits, while the terrestrial bromeliad, Encholirium spectabile, provided nectar (30.81% of the diet in November). Approximately half of the plant species (and three families) identified in this study had not been recorded previously in the diet of Callithrix. Overall, the data suggest that, while the marmosets exploit the same types of plant foods in the Caatinga, the resource base is quite distinct from that of the Atlantic Forest. Other differences, such as relatively small groups and large home ranges, may contribute to divergent ecological patterns, which require more systematic investigation. Am. J. Primatol. 75:333-341, 2013. © 2012 Wiley Periodicals, Inc.


Assuntos
Comportamento Animal , Callithrix , Dieta/veterinária , Ecossistema , Plantas Comestíveis , Animais , Brasil , Bromeliaceae , Cactaceae , Comportamento Alimentar , Flores , Frutas , Folhas de Planta , Árvores
13.
Am J Primatol ; 74(12): 1106-27, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22930419

RESUMO

Neotropical monkeys of the genera Cacajao, Chiropotes, and Pithecia (Pitheciidae) are considered to be highly arboreal, spending most of their time feeding and traveling in the upper canopy. Until now, the use of terrestrial substrates has not been analyzed in detail in this group. Here, we review the frequency of terrestrial use among pitheciin taxa to determine the ecological and social conditions that might lead to such behavior. We collated published and unpublished data from 14 taxa in the three genera. Data were gleaned from 53 published studies (including five on multiple pitheciin genera) and personal communications of unpublished data distributed across 31 localities. Terrestrial activity was reported in 61% of Pithecia field studies (11 of 18), in 34% of Chiropotes studies (10 of 29), and 36% of Cacajao studies (4 of 11). Within Pithecia, terrestrial behavior was more frequently reported in smaller species (e.g. P. pithecia) that are vertical clingers and leapers and make extensive use of the understory than in in the larger bodied canopy dwellers of the western Amazon (e.g. P. irrorata). Terrestrial behavior in Pithecia also occurred more frequently and lasted longer than in Cacajao or Chiropotes. An apparent association was found between flooded habitats and terrestrial activity and there is evidence of the development of a "local pattern" of terrestrial use in some populations. Seasonal fruit availability also may stimulate terrestrial behavior. Individuals also descended to the ground when visiting mineral licks, escaping predators, and responding to accidents such as a dropped infant. Overall, the results of this review emphasize that terrestrial use is rare among the pitheciins in general and is usually associated with the exploitation of specific resources or habitat types.


Assuntos
Comportamento Animal , Ecossistema , Pitheciidae , Animais , Feminino , Masculino , Comportamento Predatório , Estações do Ano , América do Sul
14.
Evolution (N Y) ; 15(1): 10, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35789576

RESUMO

Intelligent Personal Assistants (IPAs), such as Amazon's Alexa, are now widely used for an ample variety of tasks, ranging from personal management to education. These tools have shown considerable promise for student-educator interactions, especially at a distance, a potential that has come to the forefront during the ongoing COVID-19 pandemic. Even so, this potential is still underexploited, even in the current scenario. Alexa's apps are known as skills, which include all the different commands that Alexa is capable of executing. It is important to note, however, that the use of such technology is work-intensive and can be relatively complex. Given this, to facilitate the development of new skills in Alexa, we have developed an online tool that permits the creation of questions and answers, as well as honing the interaction between Alexa and the user. We have named this tool ForAlexa, which has two types of forms, Question-And-Answer (Q&A) and Random-Quote. Both these forms allow the user to build intents (an activity that is invoked by a spoken request from the user), but with slightly different functions. The Q&A form is used to compile answers that Alexa will offer in response to an utterance (question), while the Random-Quote extends the interaction between Alexa and the user, based on the questions asked in the first form. ForAlexa also has a help assistant, as well as a manual, which explains all the steps necessary for the design of an intent. This tool allows educators to develop apps quickly and easily for their classes and this type of app could be an alternative to be used for students with special needs, such as the visually-impaired. Supplementary Information: The online version contains supplementary material available at 10.1186/s12052-022-00169-z.

15.
Am J Phys Anthropol ; 146(3): 385-91, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21994015

RESUMO

This study presents a molecular phylogeny of the Saguinus genus, based on the analysis of the DNA sequences of five nuclear loci with Alu insertions in 10 species. The concatenated alignment produced a polytomic arrangement with four main groups, although only two clades-the Amazonian (S. midas, S. niger, and S. bicolor) and the Colombian (S. leucopus and S. oedipus) tamarins-were statistically significant. The emergence of the midas-bicolor clade was estimated at about 5 million years ago (mya), and that of the Colombian clade, at 4.6 mya. The phylogenetic relationships among the mustached tamarins (S. mystax, S. imperator, and S. labiatus) remained unresolved, as did the internal arrangement of the midas group. The lack of a clear consensus on the phylogeny of this group may be related to rapid bursts of evolutionary change within the context of a highly dynamic environment, which may be difficult to resolve using the available quantitative approaches. On the other hand, the discrepancies between mtDNA and nDNA in resolving phylogenies strongly indicate the role of reticulated evolution in the evolutionary history of this group. We hope that the advance of whole genome sequencing technology and increasing information on nuclear markers and SNPs, coupled with a better understanding of the geological phenomena that took place in western Amazonia over the past 20 million years, will shed further light on the phylogenetic history of these New World primates.


Assuntos
Elementos Alu , Evolução Molecular , Saguinus/genética , Animais , Teorema de Bayes , DNA/genética , DNA Mitocondrial/genética , Filogenia
16.
Am J Primatol ; 73(11): 1145-51, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21809365

RESUMO

One of the most common types of polyspecific association observed in Neotropical primate communities is that between squirrel monkeys (Saimiri) and capuchins (Cebus). The present study focused on association patterns in two Saimiri sciureus groups in eastern Brazilian Amazonia, between March and October, 2009. The associations were analyzed in terms of the species involved, the degree of association, and niche breadth and overlap. The study involved two S. sciureus groups (B4 and GI) on the right and left bank of the Tocantins River, respectively, within the area of the Tucuruí reservoir in southeastern Pará. Relations between species were classified as associations (individuals within 50 m and moving in the same direction), and encounters (individuals within 50 m and no coordinated movement). Group B4 was in association with Cebus apella during 100% of monitoring, and with Chiropotes satanas in 20.2%. By contrast, Group GI associated with Cebus 54.8% of the time, and with Chiropotes utahickae 2.5%. Encounters with Alouatta belzebul and Saguinus niger were recorded at both sites, with Aotus azarae and Dasyprocta prymnolopha at B4, and with Callicebus moloch, Dasyproct aleporina, Mazama gouazoubira, and Nasua nasua at GI. Overall, Saimiri had a broader niche than Cebus in terms of vertical spacing and diet, but not for substrate use. This pattern did not appear to be affected by association. While group GI spent significantly (P < 0.05) more time in association with Cebus during the wet season, group B4 associated with Chiropotes more during the dry season. Despite the higher association rates, niche overlap was greater for all variables at B4. This may reflect differences in the ranging and foraging patterns at the two sites, and the varying potential benefits of association for Saimiri.


Assuntos
Comportamento Animal , Ecossistema , Saimiri/fisiologia , Animais , Brasil
17.
Am J Primatol ; 73(12): 1199-209, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21898513

RESUMO

The feeding behavior of a group of titis (Callicebus coimbrai) was monitored over an annual cycle at a site in northeastern Brazil. Behavioral data were collected in scan samples (1-min scan at 5-min intervals), and complementary data on fruit availability and new leaf cover were collected. Feeding time accounted for 28.9% of daily activity. Fruit was the principal item of the diet (61.2% of records) and the primary category in all months except September, when it was surpassed by leaves. Young leaves were the second most important category (20.0%). The consumption of seeds and insects was prominent in November and December. Fifty-two plant species were exploited, and the Elaeocarpaceae, Myrtaceae, Sapotaceae, and Passifloraceae provided the vast majority (86.0%) of plant feeding records. The phenological record did not provide a good measure of fruit availability, but a strong correlation (r(s) =0.902, P<0.0001, n=12) was found between the consumption of leaves and the exploitation of lianas each month. Lianas accounted for 28.2% of plant feeding records, and predominated between August and December. This suggests that lianas may represent a key factor in the ability of the species to tolerate the intense habitat fragmentation found throughout its geographic range.


Assuntos
Dieta , Ecossistema , Comportamento Alimentar , Pitheciidae/psicologia , Estações do Ano , Animais , Brasil , Feminino , Frutas , Masculino
18.
Am J Primatol ; 72(6): 515-21, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20120010

RESUMO

Mycophagy is a relatively rare behavior in primates and has only been recorded in five callitrichid species. Here, we present data on the feeding ecology of a free-ranging group of Callithrix flaviceps, which was studied in the Augusto Ruschi Biological Reserve, Southeastern Brazil, in 2008. In contrast with other marmosets, which are typically gummivorous, the study group was predominantly mycophagous-insectivorous, with fungi corresponding to 64.8% of total feeding records, and gum (6.1%) and fruit (3.3%) together providing only a minor part of the diet. Prey corresponded to 25.8% of the group's diet. The fungi (Mycocitrus spp.) consumed by the marmosets were found attached to the stems of Merostachys bamboo. As the animal component of the group's diet was similar to that recorded in studies of other marmosets, we propose that fungi were exploited primarily as a substitute for plant material, in particular exudates. This highly mycophagous diet may be determined by two principal factors: (1) the abundance of fungi within the study area, and (2) the avoidance of bark gouging, for which C. flaviceps may be less specialized than most other marmosets. These conclusions are supported by comparisons with other marmoset groups, which indicate an ecological specialization for mycophagy in C. flaviceps, and that the species will resort to gummivory in habitats where fungi are scarce.


Assuntos
Comportamento Animal , Callithrix , Dieta , Comportamento Alimentar , Preferências Alimentares , Animais , Comportamento de Escolha , Feminino , Fungos , Masculino
19.
Am J Primatol ; 72(12): 1100-7, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20683881

RESUMO

Line transect surveying is a relatively rapid and efficient procedure for the assessment of primate populations; although the reliability of the resulting density estimates is affected by a number of factors, including habitat configuration. In this study, primate populations were surveyed at a highly fragmented site in northeastern Brazil, where the resident species include the endangered Coimbra-Filho's titi, Callicebus coimbrai, and the critically endangered yellow-breasted capuchin, Cebus xanthosternos. In addition to standard line transect surveys, data were collected on the composition and distribution of resident groups during playback surveys and ecological monitoring. During surveys, a 5.3-km trail system was walked regularly over a 7-month period, accumulating a total transect length of 476 km and 104 sightings of Callicebus and 41 of Cebus (as well as 19 records of a third primate, Callithrix jacchus). Data were analyzed using the DISTANCE program and the Kelker method, using the perpendicular distances to first animal sighted. Estimates of group density were highly discrepant from known values for both species; although in the case of Cebus, this seemed to reflect grouping patterns at the site. For Callicebus, population density was overestimated considerably when known group counts were used. Overall, there seems to be a need for a much more rigorous standardization of procedures, and the analysis and presentation of results, in order to guarantee the most reliable interpretation possible of the data. These considerations are especially important in the case of endangered species, such as those studied here.


Assuntos
Callithrix/fisiologia , Cebus/fisiologia , Coleta de Dados/métodos , Demografia , Pitheciidae/fisiologia , Comportamento Social , Animais , Brasil , Densidade Demográfica
20.
Biochem Genet ; 48(5-6): 472-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20087657

RESUMO

The bare-faced curassow (Crax fasciolata) is a large Neotropical bird that suffers anthropogenic pressure across much of its range. A captive population is maintained for conservation management, although there has been no genetic screening of stocks. Based on the six microsatellite markers developed for Crax globulosa, the genetic variability of C. fasciolata and possible differences between a wild and a captive population were investigated. Only three loci were polymorphic, with a total of 27 alleles. More than half of these alleles were private to the wild (n = 8) or captive (n = 7) populations. Significant deviations from Hardy-Weinberg equilibrium were restricted to the captive population. Despite the number of private alleles, genetic drift has probably promoted differentiation between populations. Our results indicate that wild C. fasciolata populations are genetically impoverished and structured, but species-specific microsatellite markers will be necessary for a more reliable assessment of the species' genetic diversity.


Assuntos
Conservação dos Recursos Naturais , Galliformes/genética , Variação Genética , Repetições de Microssatélites/genética , Animais , Espécies em Perigo de Extinção , Frequência do Gene , Polimorfismo Genético
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