Navegando por Assunto "Ecologia animal"

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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)
O boto na verbalização de estudantes ribeirinhos: uma visão etnobiológica
(Universidade Federal do Pará, 2008) RODRIGUES, Angélica Lúcia Figueiredo; SILVA, Maria Luisa da; http://lattes.cnpq.br/2101884291102108
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)
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 alimentar e dispersão de sementes por guaribas (Alouatta belzebul) na Estação Científica Ferreira Penna (Caxiuanã / Melgaço / Pará)
(Universidade Federal do Pará, 1999-04-13) SOUZA, Luciane Lopes de; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
The behaviour of two free-ranging groups of red-handed howler monkeys (Alouatta belzebul) was monitored at the Ferreira Penna Research Station (Pará) over' a thirteen-month period in 1997/98, in order to record their ecological characteristics, especially their diet and seed dispersal. Quantitative behavioural data were obtained using instantaneous scan sampling. Invariably, the howler monkeys were relatively inactive, dedicating more than half their activity time to resting, and much smaller proportions to locomotion, feeding and social behaviour. Use of the home range was strongly influenced by the distribution of food patches, in particular fruiting trees. The diet was basically folivorous-frugivorous, although fruit was the item consumed most frequently (54.1 % of feeding records for the principal group, denominated "L") in the "winter" months (November-April), whereas leaves were consumed far more frequently (84.5 %, group L) in the "summer" (May-August). Seeds took 22:49±6:12 h, on average, to pass through the digestive tract, and ingested seeds were dispersed a mean distance of 172,0±113,8 m, although this distance was significantly greater in the winter. Germination rates recorded in tests in both field and laboratory were inconclusive on the effects of ingestion on viability. The germination rate of ingested seeds was significantly greater than the control (uningested) in only a few cases, such as that of Ficus guianensis, the principal source of fruit. Even so, ingestion did not have a marked negative effect on viability in any case. Overall, the present study reforces the view of A. belzebul as a typical howler monkey, ecologically, albeit relatively frugivorous, and playing a important role as a seed disperser in the Amazon Forest.
Acesso aberto (Open Access)
Comportamento do papagaio-do-mangue Amazona amazonica: gregarismo, ciclos nictemerais e comunicação sonora
(Universidade Federal do Pará, 2007) MOURA, Leiliany Negrão de; SILVA, Maria Luisa da; http://lattes.cnpq.br/2101884291102108
In this study we carried through the Orange-winged-parrot Amazona amazonica census in a roosting site, the Parrots Island, located next to Belém, Pará. With the countings we verify that the total number of parrots, the number of isolated individuals, couples, groups of three, four and five individuals presented a fluctuation, indicating reproductive seasonality, that influences in the number of individuals with the reduction of its participation in the groups that sleep in the island during its reproductive period, since the species supplies parental cares to the offsprings. In relation to the nychtemeral cycle, we evaluate the influence of abiotic factors in the schedules of displacements of the individuals of this population in the roosting site. We establish a form to register the frequency of its arrival or exit from minute to minute and relate the data gotten with the sunset and sunrise schedules. We verify that the percentage average of individuals that arrives and leaves is significantly greater after sunset and before sunrise, respectively, and that adverse weathers conditions influence significantly in the daily movement of the parrots, masking the real positioning of the Sun, advancing or delaying its arrival and exit of the roosting site. Although the Orange-winged-parrot is a diurnal avian, they dislocate in schedules of low luminosity, being the photoperiodism a entrainment agent of its activities. About its acoustic communication, it presents 9 vocalizations in the vocal repertoire during the reproductive period, related to three different behavior categories. Moreover, it exists an individual difference in its flight contact call and populational dialects between the studied populations.
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)
Comportamento, ritmo de atividade e arquitetura das galerias de Uca maracoani (Latreille, 1802) e Minuca rapax (Smith, 1870)
(Universidade Federal do Pará, 2016-11-22) BELÚCIO, Lucinice Ferreira; GOUVEIA JUNIOR, Amauri; http://lattes.cnpq.br/1417327467050274
This study aimed to elaborate the behavioral budget and to obtain the level of annual activity on the surface as well as the shape of the galleries of Uca maracoani and Minuca rapax, which coexist in the intertidal region of the Curuperé mangrove, Curuçá, Pará, During four sequential lunar periods, from October to December of 2013, the behavior of the species was shot to obtain the budget. The annual activity of the species was evaluated by shooting the number of active animals and galleries at four sites along the river. To evaluate the shape and distribution of the galleries paraffin casts were obtained in two stations with mud sediment and sand-muddy. In the ethogram of the species, ninety-five behaviors were recorded, grouped into the categories: Feeding, Reproductive, Walking and Running, Acoustics and Sysmics, Territorial, Agonistic, Maintenance and Grooming. The following categories were important to differentiate the energy budget of the species: Feeding, Territorial, Acoustics, Reproductive. Considering the difference of niches of males and females of the same species, the following behaviors are noteworthy: Feeding, Walking and Running, Territorial, Maintenance, Acoustics and Sysmics, Reproductive, Grooming. A great amount of rainfall (February) and low humidity (October) decreased animals activity at the surface, while the climate in June allowed a higher activity of these animals at the surface. Despite some similarities in the architecture of the galleries of the two species, the differences in volume and depth suggest that they present individual scales that are very different from influences in the bioturbation process. However, this process can be counterbalanced by the population density of each species and its activity rate.
Acesso aberto (Open Access)
Desenvolvimento colonial em abelhas nativas sem ferrão Amazônicas (Apidae: Meliponini): tamanho populacional, nutrição e alocação fenotípica
(Universidade Federal do Pará, 2019-11) LEÃO, Kamila Leão; MENEZES, Cristiano; http://lattes.cnpq.br/9845970576214577; CONTRERA, Felipe Andrés Léon; http://lattes.cnpq.br/0888006271965925; https://orcid.org/0000-0002-7078-5048
Meliponines or stingless bees comprise a diverse and abundant group of eusocial bees, which live in perennial colonies and have a wide range of behavioral characteristics. The general objective of this thesis is to understand population dynamics and developmental patterns of Amazonian stingless bee species. In Section I, we evaluated the population size and several biological characteristics of colonies (e.g. worker external activity, queen egg-laying rate) of five stingless bee species in order to understand how colony characteristics relate to population size. We found an average adult population of 1,046.00 in Melipona flavolineata, Friese, 1900, 592.75 in Melipona fasciculata, Smith, 1854, 7,404.00 in Scaptotrigona aff. postica (Latreille, 1807), 2,425.33 in Frieseomelitta longipes (Smith, 1854) and 404.75 in Plebeia minima (Gribodo, 1893). External activity was the variable that best explained population size. In Section II we investigate the longevity of stingless bee workers fed soy-based diets. Our objective was to compare the effect of a semi-artificial soybean diet versus a natural diet on the longevity of adult workers of two stingless bee species (Melipona flavolineata Friese, 1900 e Scaptotrigona aff. postica (Latreille, 1807)). We found a higher longevity in workers that consumed only pollen compared to those that consumed the soybean diet for both species studied. Finally, In Section III we evaluated the phenotypic allocation in stingless bees. In this work we investigate phenotypic allocation as a response to climatic and environmental variation, using the stingless bee Melipona fasciculata Smith, 1854 as a model species. Our results reveal that phenotypic allocation in M. fasciculata was strongly associated with seasonal variation and not the quality of the environment (local). The production of virgin queens was influenced by season and year (being higher in the dry season), but not by location. Male production was explained by season and local environmental variables and season and study year influenced the percentage of workers produced, showing differences between years. We believe that this thesis contributes to our understanding of the natural history of Amazonian stingless bees and the development of regional meliponicultural practices.
Acesso aberto (Open Access)
Dimorfismo sexual quanto ao tamanho em três espécies de sabiás amazônicos (Aves: Passeriformes: Turdidae)
(Universidade Federal do Pará, 1997-11-28) SOUZA, Suely Basilio de; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Three species of Brazilian thrushes replace one another ecologlcally along the primary and secondary forests of the Eastern Amazonian Region, Turdus T fumigatus and T. leucomelas. These three species are monochromatic, i. e., me and female have similar plumages. Whether these species are monomorphic (i.e., if males and females are of similar size) or not has not been previously investigated. Studies in Mexican forests indicated that some monochromatic birds from the Neotropical Region are in fact cryptically dimorphic, i. e., males and females differ statistically in size when suitable statistic techniques are appiled. This work has three main objectives: (a) to evaluate the pattern of sexual dimorphism in size in T. albicollis phaeopygus, T. fumigatus fumigatus and T. ieucomelas albiventer, (b) to contribute to the study of the sexual dimorphism in size of Neotropical monochromatic birds, and (c) to provide subsidies for evolutionary and ecological studies on the genus Turdus, and also on the family Turdidae as a whole. The working hypothesis here was the three species of Turdus studied would be cryptically dimorphic in a pattern similar to the passeriform forest birds previously studied in the Mexican forests. Of the three species studied, two were found to be monomorphic (T. f fumigatus and T. a. phaeopygus) and one cryptically dimorphic (T. 1. albiventer). In the only cryptically dimorphic species, males differ significantly from females in the length of the wing, tad, tarsus and fourth toe claw. However, a reliable sexual identification cannot be performed from the discriminant linear function obtained. The reason the three species of Turdus are monomorphic or cryptically dimorphic may be associated with their pre-reproductive behavior. During the mating season. vocalization seems to be more important to attract females and for territorial defense than plumage or size. Thus, there is a strong selective pressure for vocalization of males and weak or non-existent pressure for body size. It is suggested that more research for the evaluation of sexual dimorphism in other species of Turdus and. a phylogenetic analysis of this large genus are indispensable in clarifying the evolution of patterns of sexual dimorphism in thrushes.
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
Acesso aberto (Open Access)
Ecologia comportamental de Alouatta belzebul (Linnaeus, 1766) na Amazônia Oriental sob alteração antrópica de hábitat
(Universidade Federal do Pará, 2005-03-14) CAMARGO, Carolina Cigerza de; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
The behavioural ecology of two groups of red-handed howler monkeys (Alouatta belzbul) was monitored ou Gennoplasma island (Tucuruí, in the Brazilian state of Pará), between April and September 2004. The two study groups were of similar size and composition, but inhabited different forest types: native forest (group P) and a plantation of native tree species (group Q). Quantitative behavioural data were collected in three-minute scan samples conducted at ten-minute intervals. "AH events" sampling was used to record rare activities such as social and interspecific interactions. Resting was the predominant activity in both groups (P: 67.3%; Q: 61.9%), followed by feeding (P: 15.7%; Q: 21.4%), and locomotion (P: 15.8%; Q: 15.5%). The proportions of the first two categories were significantly different. The diet of both groups was folivorous-frugivorous, supplemented mainly by flowers. No significant seasonal variation was recorded in the diet of either group. The groups occupied home ranges of similar size (P: 5.25 ha; Q: 5.50 ha), although group P travelled 612 m ou average per day, as against 541 m for group Q. Both groups used preferentially their "original" habitat (group P: native forest; group Q: plantation), and the uppermost forest strata. Interspecific interactions were pacific, and social interactions were rare. The results of the present study present greater similarities with those of A. belzebul studies carried out in fragments of Atlantic Forest than at other Amazonian sites (continuous forest). This suggests that habitat disturbance may be a more important determinant of behaviour patterns than the characteristics of the biome. Overall, the results of the present study conicide with the typical Alouatta patterns of behaviour described in the literature.
Acesso aberto (Open Access)
Ecologia de cuxiús (Chiropotes Satanas) na Amazônia oriental: perspectivas para a conservação de populações fragmentadas
(Universidade Federal do Pará, 2002-10-04) SANTOS, Ricardo Rodrigues dos; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
Found throughout much of Brazilian Amazonia, the bearded sakis (Chiropotes albinasus and Chiropotes satanas) are primates specialised for seed predation. In order to delineate activity patterns and the exploitation of dietary resources, two social groups (10 and B4) of C. satanas were monitored between July and November, 2001, at the reservoir of the Tucurui hydroelectric power station in the state of Pará. Group 1G (C.s. utahicki), with 24 members, occupies an island of 100 ha, whereas group B4 (C. s. satanas), with 27 members, inhabits an area of continuous forest, both protected by Eletronorte S.A. Quantitative behavioural data were collected in scan samples, with a 5 min interval, collected continuously during five days per month. Complementary observations were recorded in ad libitum fashion throughout the study period, which started in April. A total of 5490 reords were collected for group 1G (only the feeding behaviour of group B4 was analysed here), distributed between feeding (58,8%), locomotion (30,8%), rest (9,5%) and other activities (0,9%). These proportions varied considerably between months. One hundred and ten plant species were exploited by the sakis. As expected, seeds were the main dietary item in both cases (group 1G: 75,6%, n = 2721 records; group B4: 49,6%, n = 1865). Remaining dietary items included flowers, fruit, leaf shoots and the mesocarp of palm fruits, although insectivory was not observed. Similar variation in the consumption of different items was observed in the two groups between September and November. Taxonomic diversity of the diet of group 1G was greater than that of B4, as was its home range (100 vs. 57 ha). No systematic variation was found in foraging party size. The results of the study indicate that the remnant populations of bearded sakis in the region's fragmented landscape have good long-term potential for conservation.
Acesso aberto (Open Access)
Ecologia de dois grupos de sagüis-brancos, mico argentatus (Linnaeus 1771) em um fragmento florestal natural, Santarém-Pará
(Universidade Federal do Pará, 2006) CORRÊA, Honorly Kátia Mestre; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
This monograph presents the results of a long-term study of the behaviour and ecology of two free-ranging groups of Mico argentatus in a natural fragment of forest isolated within a matrix of savanna vegetation in the region of Alter do Chão, in central Amazonia. The groups, denominated Cm1 and Cm2, were habituated and then monitored during 12 months in 2000 and four months in 2001 (Cm1), and seven and three months, respectively, in the two years (Cm2). Analyses of temporal variation were based on three distinct seasons (early wet, late wet, and dry seasons) of 2000, and the longitudinal comparison of July and September in 2000 and 2001. Relationships between ecological variables (abundance of principal resources: fruit and insects) and the ecological and behavioural characteristics of the group were evaluated. The two groups presented distinct composition and sizes, varying from 4-8 and 8-11 members in Cm1 and Cm2, respectively. Quantitative data were collected using scan sampling, with a scan of one minute duration conducted at five-minute intervals throughout the daily activity period of the group. The results show that both groups dedicate more than half their time to foraging and feeding. Diet was composed of fruit, nectar, gum, and animal prey (invertebrates – primarily orthopterans, formicids, and coleopterans – as well as lizards and amphibians). In 2000, groups Cm1 and Cm2 occupied home ranges of 11.5 ha and 14.6 ha, respectively. The seasonal analysis showed a similarity between groups in the systematic allocation of increasing time to foraging and feeding as non-gum resources became scarcer. In addition to a 30% decline in precipitation between years, the longitudinal analysis revealed considerable changes in the composition and spatial distribution of the study groups. These changes appear to have had the main influence on behaviour patterns, resulting in contrasting trends in the two groups. Overall, despite important similarities, the marked differences in many aspects of the ecology of two groups occupying the same fragment constituted one of the principal results of the study, in addition to the considerably variation among seasons and between years. The behavioural strategies records in the study appear to reflect not only the typical variability and flexibility of the callitrichids, but also the ecological conditions imposed by the fluctuations in the availability of resources within a fragment of reduced size.
Acesso aberto (Open Access)
Ecologia e comportamento do Cuxiú-Preto (Chiropotes Satanas) na paisagem fragmentada da Amazônia Oriental
(Universidade Federal do Pará, 2006-06-13) VEIGA, Liza Maria; GALVÃO, Olavo de Faria; http://lattes.cnpq.br/7483948147827075; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
Bearded sakis are frugivores specialised for seed predation. The black bearded saki (Chiropotes satanas) is endemic to a densely populated and deforested area in eastern Amazonia in Brazil and is threatened with extinction. The principal objective of this study was to research the behaviour and ecology of two groups of black bearded sakis living under different degrees of habitat fragmentation, to understand how ecological parameters in these different settings influence behavioural strategies. In addition, the study aimed to identify factors that may limit the long-term viability of the black bearded saki and identify information that may contribute to conservation and management plans. The study took place on the right bank of the Tocantins River in the Tucuruí Reservoir, Pará State, Brazil (415'S, 4931'W). Two groups of bearded sakis were studied: one (denominated T4) in a large mainland fragment (1,300 ha - 39 members), and one on a small (19.4 ha - eight members) forested island. Twelve months behavioural sampling (1,153 observation hours) was undertaken using both scan and behaviour-sampling methodologies for 4 to 5 consecutive days per month per group. In addition to collecting activity budget data, all food resources were documented, daily routes plotted and intraspecies and interspecies social interactions recorded. Botanical transects (10 x 100 ha) covering one hectare at the T4 site and 0.5 hectare on the island were established, and a subsample of trees (≥ DAP 10cm) and lianas (≥ DAP 5 cm) marked and measured for a floristic inventory and phenological data collection which took place at 30-day intervals over 14 months. The two groups differed in all aspects of their behaviour and ecology. Time spent in different activities varied significantly between the groups. Moving (35.4%) comprised the largest proportion of annual budget in the T4 group, while the Island group devoted more time to feeding (30.0%). Social interactions accounted for a relatively large proportion of activity budget for both groups (T4 8.5%; Island 15.2%). Over the study, the two groups consumed a large number of different plant species (T4 173; Island 132; both groups 240) and their diets varied significantly in terms of items consumed and taxonomic composition. Both groups spent most of their time consuming seeds (T4 54.0%; Island 59.9%), however other items, including fruit pulp (T4 25.0%; Island 13.7%), flowers (T4 12.3%; Island 17.4%) and to a lesser extent pith and arthropods were also included in their diets. Members of the T4 group used an area of 98.6 ha and the island group, 17.2 ha. Use of space and daily path length (T4 4025 m 994 m; Island 2807 m 289 m) varied between groups and was linked in T4 group to the variation in group size throughout the year as a result of their complex fission-fusion sociality, the island group on the other hand was more cohesive. Variations in ecology and behaviour of the two groups were linked to differences in their respective habitats. The size of the sites was important but so too was the variation in the availability of food. Results from the floristic inventory revealed a greater diversity of different species on the T4 site, however important food species were either missing or available in varying amounts at both site. In addition to the intrinsic value of the knowledge of ecological characteristics of the bearded saki the detailed knowledge accumulated this study will help in the formulation of conservation action and management plans and in the identification of the factors which limit the long term viability of remaining populations in the fragmented landscapes of eastern Amazonia.
Acesso aberto (Open Access)
Ecologia trófica e espacial de Dendropsophus melanargyreus (Cope, 1887), D. minutus (Peters, 1871) e Scinax ruber (Laurenti, 1768) (Anura: Hylidae) em um fragmento Florestal na Amazônia oriental
(Universidade Federal do Pará, 2016-04-20) BARROS, Rafael de Assis; COSTA, Maria Cristina dos Santos; http://lattes.cnpq.br/1580962389416378
Three key factors determine the main niche of the species: diet, use of space and time. The trophic and spatial niche show an important role in the reproductive success of frog species than cohabit restricted environments as temporary ponds. The target species of this study are common in temporary ponds in areas of urban fragments located in the eastern Amazon region. With this, our main objective were analyse how three species of sintopics hylids, share the trophic and spatial resources among themselves, and what mechanisms are used to avoid potential competition. For this, we use different measures and diet analyses and habitat use, and test whether the species are sensitive to environmental and structural factors in ponds where they occur. None of the factors (diet, use of space, influence of environmental factors) was limiting to the coexistence of the species, due no there are negative interaction between them. The studied hylids utilized several strategies than help reduce overlap among the species, how the use of different microhabitats, perches at different heights, ponds with different depths, using different degrees of food importance to items shared by species and the use of unique food items of each specie. In addition, environmental and structural factors of microhabitats, influence directly the abundance of two of the species studied, regulating their population size and auxiliary in their reproductive period.
Acesso aberto (Open Access)
Ecologia, comportamento e associações poliespecíficas do macaco-de-cheiro (Saimiri sciureus), Amazônia Oriental
(Universidade Federal do Pará, 2010) MAGALHÃES, Tatyana Pinheiro; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627
Acesso aberto (Open Access)
Efeito da paisagem sobre a diversidade de vertebrados terrestres em fragmentos florestais na Amazônia Oriental
(Universidade Federal do Pará, 2019-01-17) SILVA, Jacqueline Almeida da; MASCHIO, Gleomar Fabiano; http://lattes.cnpq.br/7967540224850999
Context: The advance of anthropic activities on the Amazonian frontier has provoked an intense process of forest fragmentation that reduces biodiversity and subjects the species to a situation of high vulnerability. Objectives: To test the relation of fragment size, isolation and characterization of the forest fragments matrix, on the wealth of amphibians of the order Anura, reptiles of the order Squamata and mammals of small, medium and large size. Methods: The study was carried out in 12 fragments in the northeast of the Amazon. The size of the fragment was calculated in hectares, the isolation in ENN_MN (mean of the euclidean distance of the nearest neighbors) and the matrix was organized into categories. These landscape metrics were considered as explanatory variables and calculated on three spatial scales: 1, 2 and 3 km. The relationship of the metrics with the richness of terrestrial vertebrates was evaluated through multiple regressions with model selection. Results: 130 species of terrestrial vertebrates were recorded. There was no significant effect of fragment size on spatial scales for any group of species. The isolation was significant only in the 3 km scale for the group of amphibian and snake species. The category of open areas in the matrix was significant in the three spatial scales for the group of species of lizards and mammals of medium and large size. Conclusions: The landscape configuration is extremely important in the context of fragmentation, there were different responses from taxonomic groups, possibly due to differences in habitat use.
Acesso aberto (Open Access)
Efeito das paisagens modificadas por práticas agrícolas sobre a composição e estrutura das assembléias e espécies de Drosophilidae (Diptera)
(Universidade Federal do Pará, 2014-11-28) FURTADO, Ivaneide da Silva; MARTINS, Marlúcia Bonifácio; http://lattes.cnpq.br/8882047165338427
The Amazon Rainforest holds the largest biodiversity in the world. It occupies more than 40% of the Brazilian surface. In recent years the rates of forest loss and degradation of Amazonia have considerably increased as a result of agricultural expansion, creating a mosaic of highly modified landscapes. These changes endanger both biodiversity and ecosystem services associated with it, besides causing severe stress on the species. Effects of stress can result in physiological changes that are reflected in morphological differentiation among remnant populations, which now occupy the new landscape. The objective of this study was to test the effect of some types of land use on the assembly of frugivorous Drosophilidae and on the morphology of some species originally settled within the forest areas that have become a patchwork landscape containing forest fragments, ecological succession and crop zones. The first study was conducted in three agricultural villages and the second within six locations, including three preserved forest areas. Sampling was performed in a standardized manner, with traps placed along the established transects on the use of predominant land within the area of study. Our results showed that the richness of the species did not differ between different types of land use, but the distributions and abundances of the species' composition were clearly distinct between intensive agricultural uses and forest systems. The forest's coverage and the relative humidity were the variables determining the distribution of the species. The agricultural uses were characterized by cosmopolitan non-native species associated with more open areas. There were found morphological differences between the individuals caught in the areas of preserved forest and agricultural use zones, regardless of the species. Surprisingly, the number of individuals captured in the forests was always lower compared to those captured in the more intensive types of use. These results show the effects of landscape mutation on the remaining populations of native species, indicating the range of quantitative and qualitative alterations on the set of species. However, the maintenance of the forest patches on areas of agricultural use can benefit the permanency of native species in these landscapes.