Navegando por Assunto "Biogeografia"

Agora exibindo 1 - 20 de 56

Acesso aberto (Open Access)
Análise biogeográfica da avifauna de uma área de transição cerrado-caatinga no Centro-Sul do Piauí, Brasil
(Universidade Federal do Pará, 2001-01-16) SANTOS, Marcos Pérsio Dantas; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Acesso aberto (Open Access)
Análise da variabilidade genética e estudo populacional de Antilophia bokermanni (Aves: Pipridae) com implicações para sua conservação
(Universidade Federal do Pará, 2010) RÊGO, Péricles Sena do; SCHNEIDER, Horacio; http://lattes.cnpq.br/3621033429800270
The Araripe Manakin Antilophia bokermanni (Passeriformes, Pipridae) is the most threatened member of this family, and is classified as “critically endangered”. With an estimated population of only 800 individuals, this species is endemic to a small area (approximately 30 km²) of forest on the slopes of the Araripe Plateau in northeastern Brazil. The urgent need for the implementation of an effective conservation program for the Araripe Manakin has stimulated intensive research into various aspects of its biology. In the present study, we examined sequence variation in segments of the mtDNA and ncDNA in specimens of A. bokermanni and A. galeata. The current analysis provides no evidence for population substructuring nor for a history of population expansion of A. bokermanni. The genetic variability is slightly reduced in comparison with its sister species, but their similarity indicates a relatively recent process of separation, indicated by retention of ancestral polymorphisms (incomplete lineage sorting) all markers. We also did not detect any association between plumage variation and nucleotide variation at MC1R in genus Antilophia. This study represents a contribution of genetics to the Conservation Plan of Araripe Manakin (Antilophia bokermanni).
Acesso aberto (Open Access)
Avifauna do estado de Roraima: biogeografia e conservação
(Universidade Federal do Pará, 2005) SANTOS, Marcos Pérsio Dantas; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Acesso aberto (Open Access)
Avifauna do estado do Acre: composição, distribuição geográfica e conservação
(Universidade Federal do Pará, 2009) SILVA, Edson Guilherme da; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
The Brazilian state of Acre borders Peru and Bolivia, and is located in the lowlands of the southwestern Amazon basin, close to the foothills of the Andes, in a region considered to be biologically megadiverse. Despite this, the region is still relatively poorly‐known in scientific terms, and is considered to be a priority for further biological surveys. With the aim of contributing to the understanding of the bird fauna of southwestern Amazonia, the principal objective of the present study was to evaluate these three questions: (a) How many and which bird species are found in Acre? (b) How are the species distributed in the state? and (c) What is the conservation status of the resident species? These questions were evaluated through a number of different approaches: (a) a comprehensive review of the literature; (b) field surveys over a two‐year period, including the recording and collection of voucher specimens; (c) production of distribution maps for each taxon (including species and subspecies); (d) distribution of the taxa among the state’s three major interfluvia or subregions (east, central, and west); (e) identification of zones of contact and hybridization, based on the distribution of parapatric species within the state; (f) estimation of the potential distribution of the taxa within the state of Acre, based on the extrapolation of the area occupied by that of each ecological unit (phytophysionomy) in which they were recorded; (g) assessment of the conservation goals for each resident taxon; and (h) a gap analysis, based on the overlap of the potential distribution maps with the state’s protected areas. The gap analysis was conducted with reference to three different scenarios: (a) inclusion of all the protected areas; (b) inclusion of only the fully‐protected area exclusive sustainable‐use units and indigenous reservations; and (c) including fully‐protected and sustainable‐use units, but excluding indigenous reservations. The literature review and surveys (historical and current fieldwork) began in August, 2005, and continued until December, 2007. At the end of this period, a total of 7.141 records of birds had been accumulated for the whole of the state of Acre. Of these, 4.623 are of museum specimens, 2.295 (49,6%) of which were collected during the present study. The presence of 655 biological species was confirmed for Acre, distributed among 73 families and 23 orders. One direct result of the study was the addition of five new species to the list of Brazilian birds. Fifty‐nine migratory species were also recorded, including 30 (50,8%) Nearctic and 18 (30,5%) austral migrants, as well as 11 (18,6%) considered to be intratropical migrants. Forty‐four of the species recorded in the study are endemic to the Inambari endemism center. Of the 556 taxa of forest birds resident in Acre, 405 (72,8%) are found in all three subregions, 56 (10,0%) were recorded only in the western subregion, 30 (5.3%) in the eastern subregion, whereas only three (0,5%) were exclusive to the central area. At least six pairs of sister taxa have an allopatric distribution in the state, while 15 sets of taxa present a parapatric distribution. Two zones of secondary contact (east‐west) and two possible hybrid zones (east‐west) were identified within the state. The gap analysis revealed that, under scenario (a), 87,1% of the taxa were fully protected (100% conservation target), and 12% were considered intermediate, that is, partially protected, whereas only 0.8% were completely unprotected. In scenario (b), by contrast, only 0,6% of the taxa were fully protected, 97.6% were partially protected, and 1,8% were totally unprotected. In the third scenario (c), 73,5% of taxa were fully protected, 25,5% partially protected, and only 0,8% completely unprotected. The principal conclusions reached in the present study were: (a) the Brazilian state of Acre has an extremely rich bird fauna, although the number of species recorded should still increase as new surveys are conducted; (b) the Purus and Juruá rivers do not constitute physical barriers to the dispersal of most bird species resident in Acre; (c) the existence of zones of secondary contact not related to the state’s principal river systems supports the conclusion that factors other than physical barriers determine the present‐day pattern of distribution of some of the resident bird taxa in Acre; (d) that the number of “gap” and “partial gap” bird species in Acre is very low when the full protected area network is considered, although this number increases with the exclusion of indigenous reservations, and in particular, sustainable‐use conservation units; and (e) the only species completely unprotected by the state’s conservation network are those restricted to the campina and campinarana ecosystems of western Acre, which indicates a clear need for the establishment of one or more conservation units in this region with the specific aim of protecting this distinct type of ecosystem.
Acesso aberto (Open Access)
Bathymetric trends of northeastern Brazilian snappers (Pisces, Lutjanidae): implications for the reef fishery dynamic
(2005-09) FRÉDOU, Thierry; FERREIRA, Beatrice Padovani
The investigation of bathymetric distribution of five snappers caught along the Brazilian Northeastern coast by artisanal fleets through the analysis of the catch composition and relative abundance (CPUE) showed that, on the overall, fished mean size increased along depth and that particular species dominated the catch according to the depth strata. Mutton snapper, L. analis, yellowtail snapper, L. chrysurus, and dog snapper, L. jocu were mainly caught at intermediate depth (20-80m) whereas lane snapper, L. synagris, and silk snapper, L. vivanus, inhabit respectively shallow (<20m) and deep (>80 m) waters. Each fleet category exploited preferentially a particular combination of species and their size range. The fleet dynamic of the Northeast Brazil is technologically heterogeneous and determines the catch composition. Geographical distribution of the fishery and technical interaction between fleets and gears should be considered by the management of these species in order to maintain the sustainability of the stock and to guarantee the continuance of the resource.
Acesso aberto (Open Access)
Biogeografia e filogeografia comparada do complexo Micrastur ruficollis (Aves, Falconidae)
(Universidade Federal do Pará, 2012) SOARES, Leonardo Moura dos Santos; ALEIXO, Alexandre Luis Padovan; http://lattes.cnpq.br/3661799396744570; SANTOS, Marcos Pérsio Dantas; http://lattes.cnpq.br/7941154223198901
Acesso aberto (Open Access)
Campylorhamphus procurvoides successor (Aves: Dendrocolaptidae) is a junior synonym of Campylorhamphus trochilirostris notabilis
(2009-09) PORTES, Carlos Eduardo Bustamante; ALEIXO, Alexandre Luis Padovan
The taxonomy of the genus Campylorhamphus Bertoni, 1901 is still uncertain, with many inconsistent evolutionary patterns implied by current taxonomy. A re-analysis of the type-series of Campylorhamphus procurvoides successor Todd, 1948 revealed that the holotype is indistinguishable from Campylorhamphus trochilirostris notabilis Zimmer, 1934, while the paratypes belonged either to the latter taxon or to a second already named taxon (Campylorhamphus trochilirostris snethlageae Zimmer, 1934), and a third and yet undescribed taxon allied to Campylorhamphus procurvoides. Here, we present statistical analyses of morphological data supporting the synonymization of C. p. successor into C. t. notabilis, the name with priority. Our findings resolve the long-standing controversy related to the distribution of Campylorhamphus procurvoides populations in the várzea habitats of the lower Amazon River.
Acesso aberto (Open Access)
Caracterização morfológica de Liophis reginae semilineatus (Wagler, 1824) e Liophis reginae macrosomus (Amaral, 1935), e o status taxonômico de Liophis oligolepis Boulenger, 1905
(Universidade Federal do Pará, 2002-10-25) COSTA, Robson Gil Neris; PRUDENTE, Ana Lúcia da Costa; http://lattes.cnpq.br/1008924786363328
The Brazilian subspecies of Liophis reginae (Liophis reginae macrosomus and Liophis reginae semilineatus) were analyzed, in order to characterize the two taxa and to verify the validity of Liophis oligolepis, considered a synonym of Liophis regime semilineatus. External morphology, cranial osteology and hemipenis were examined. Based on a MANOVA, significant sexual differences in head and body variables were identified. A discriminant analysis function (DAF) was performed for males and females separately, in order to maximize in a multivariate space the differences between the three previously defined taxa: Liophis reginae semilineatus, Liophis reginae macrosomus, and Liophis oligolepis. The first discriminant component in males separated clearly Liophis reginae semilineatus and Liophis oligolepis, while Liophis reginae semilineatus and Liophis reginae macrosomus separated at the second discriminant component. In females, the first disctiminant component separated Liophis oligolepis from Liophis reginae semilineatus and Liophis reginae macrosomus. When both sexes were analysed together, for the pairs of taxa Liophis oligolepis - Liophis reginae semilineatus, and Liophis reginae semilineatus - Liophis reginae macrosomus, both pairs were separated by the first discriminant component. Since some specimens of Liophis reginae semilineatus and Liophis reginae macrosomus were registered beyond their previous known distribution, a DAF was applied to verify if these specimens grouped within their presumed taxa or geographically. The first possibility occurred, supporting the validity of each taxon and raising the question of their taxonomic status. The hemipenian morphology does not differ between Liophis reginae semilineatus, Liophis reginae oligolepis and Liophis reginae macrosomus. The three taxa present similar skulls, although differences were observed between the parietal bones of Liophis reginae semilineatus and Liophis reginae oligolepts. The validity of Liophis oligolepis was corroborated, based on meristic, morphometric and morphological characters. Future studies will be necessary to test the Liophis reginae semilineatus and Liophis reginae macrosomus status.
Acesso aberto (Open Access)
Composição e biogeografia da avifauna das ilhas Caviana e Mexiana, foz do Rio Amazonas
(Universidade Federal do Pará, 1994-01-14) HENRIQUES, Luiza Magalli Pinto; OREN, David Conway; http://lattes.cnpq.br/5451507856491990
The islands of Caviana and Mexiana, located in the mouth of the Amazon River, are composed of fluvial sediments and well consolidated lands that date from the Terciary and that were separated from the continent by tectonic action at the beginning of the Holocene. The composition of the avifauna of these islands is analized both from the biogeographical and the ecological points of view. I registered 148 bird species for Caviana Island and 183 for Mexiana Island. The discrepancy between the size of the two islands (Caviana is larger than Mexiana) and the number of species observed is due to undersampling of Caviana. However, the analysis of faunal composition demonstrated that Caviana is richer in forest species than is Mexiana. In contrast, Mexiana showed a greater richness of birds of open habitats. These differences suggest that the rising of sea level at the beginning of the Holocene caused the extinction of greater part of the fauna of the understory ou Mexiana. The portions of Mexiana Island with "teso" vegetation were not submerged, maintaining their characteristic avifauna, which is also represented on Marajó Island. To analyse of the distribuitions of 157 species I subdivided the avifauna into seven categorias: widespread distribution in South America (77 species); widespread Amazonian distribution (25); distribution restricted to eastern Amazonia (7); distribution restricted to south of the Amazon River and east of the Tapajós River (3); distribution restricted to várzea (19); widespread distribution in northern Amazonia and absent from the Tocantins-Xingu interfluvium (5); and widespread distribution in Central Brasil (21). I did not find elements restricted to the Tocantins-Xingu interfluvium. This fact is related to ecological rather than historical factors. The pattern related to northern Amazonia can be interpreted as the result of recent dispersal, the system of islands at the mouth of the Amazon, or by the formation of the Purás and Gurupá Arches, which, associated with the lowering of sea level during Pleistocene, established a connection between lhe right and left banks of the Amazon River. The dispersal occurred in both directions, explaining lhe existence of a large number of species and subspecies with distributions restricted to eastern Amazonia, as well as the dispersal of Central Brasilian elements to north of the Amazon River. This last component of the avifauna is a1so related to the expansion of open vegetations, characteristic of Central Brazil, during glacial periods.
Acesso aberto (Open Access)
A comunidade ictica e suas interrelacões tróficas como indicadores de integridade biológica na área de influencia do projeto hidrelétrico Belo Monte-Rio Xingu, PA
(Universidade Federal do Pará, 2004-04) CAMARGO-ZORRO, Mauricio; ISAAC, Victoria Judith; http://lattes.cnpq.br/3696530797888724
This study presents applied methodologies to better understand the dynamics of mechanisms characterizing a portion of the Xingu River, with respect to fish communities living in that environment. Through the study of the ichthyofauna it is aimed to verify various environmental standard patterns, in order to assess the current conservation state of a part of the Xingu River. Based on surveys of the local ichthyofauna conducted over seasonal variations, analyses were conducted at the specieS, population and trophic guild levels. With regards to the ecological population level, study of biological parameters such as individual growth rates, asymptotic body length, mortality rates and size at first maturity were good indicators for a better understanding of the life history of those fish groups. Therefore a trend was observed in which species of relatively small body size to followed a "r" type strategy, whilw species of larger body sizes would follow the "k" strategy tactics. From a functional point of view, it was verified that guild community structure is not only a good indicator of convergence patterns to similar ecosystems as like the Xingu River studied stretch, but also a tool to assess its conservation status. A steady- state ecosystem model for the medium Xingu River sector indicated that it is a system highly instable, and simultaneusly look like a mature seasonal system. An apparent seasonal restriction of food availability observed in the studied river section could imply optimum use efficiency and transfer of the trophic resources. A biogeographic study was undertaken based on species occurrence in order to conceptualise the River stretch comprised between the confluences of the Iriri and Xingu Rivers up to the vicinity of of the village Senador José Porfirio, in the Xingu basin. By means of this analysis, it was possible to demonstrate that the medium upstream of waterfalls) and lower (downstream) courses of the Xingu River are parts of two endemic areas. The low affinity of species composition observed in these two sectors is attributed to geographic variations in the landscape. Therefore, the boundaries of the waterfalls around the village of Belomonte and the influence of the Amazon River in the lower Xingu course could trigger differences in ichthyofaunal composition and species abundance when compared to the medium course of that river. Finally, the importance of maintaining all hydrologic connectivity is pointed out in order to maintan the unity of the system, from the headwaters to the mouth. Impacts on environmental processes and fish populations in the medium course of the Xingu River as a result of the eventual construction of the Belemonte hydroelectric dam are discussed.
Acesso aberto (Open Access)
Conservação de tartarugas marinhas na costa maranhense, Brasil
(Universidade Federal do Pará, 2022-03) RIBEIRO, Luis Eduardo de Sousa; BARRETO, Larissa Nascimento; http://lattes.cnpq.br/1295307492454506; HTTPS://ORCID.ORG/0000-0002-3396-4821; PEZZUTI, Juarez Carlos Brito; http://lattes.cnpq.br/3852277891994862; https://orcid.org/0000-0002-5409-8336
Sea turtles have a long history of human exploitation around the world, which has contributed to the species population decline, along with other threats, mainly by accidental capture during fishing, habitat destruction, and pollution. Currently, interaction with fishing is the largest cause of mortality among sea turtles, followed by ingestion of inorganic material (garbage). The waste accumulation in the oceans, mainly plastic, has attracted considerable attention in recent decades since pollution is a major threat to marine life. In this study, we mapped the occurrence and nesting areas of each sea turtles in the coastal zone of Maranhão; analyzed the frequency of strandings all over the years; and evaluated the impacts on sea turtle populations in the Lençóis Maranhenses National Park, as well as diet composition and ingestion of solid waste. This research includes records of strandings of live or dead animals between 2005 and 2020, coming from the database of the Projeto QUEAMAR – Quelônios Aquáticos do Maranhão - UFMA - Federal University of Maranhão, and bi-monthly campaigns to Lençóis Maranhenses National Park. We observed five species of sea turtles along the entire Coast of Maranhão and reproductive records for two of them. From the impacts observed, anthropic interaction was the most observed factor (n=35), with drowning and amputation being the principal consequences of intermeshing (n=12). Intestinal obstruction caused by ingestion of inorganic material was also frequently observed (n=13). During this research, two Marine Seismic Surveys 3D were conducted to prospect for oil and gas, which coincided with a significant increase in the frequency of strandings in Lençóis Maranhenses National Park, possibly caused by noise pollution through noise swells generated by air cannons. Although the Maranhão coast is covered by legally protected areas, such as the Lençóis Maranhenses National Park and the Cururupu Extractive Reserve, long-term studies with species of international migratory cycle, such as sea turtles, which occupy an important position in the conservation scenario, allows detecting trends and temporal changes, as well as evaluating the impacts of anthropogenic activities in coastal areas.
Acesso aberto (Open Access)
Descrição e notas taxonômicas comparativas das terminálias femininas de espécies de Peckia robineaudesvoidy, 1830 (Diptera, Sarcophagidae) da Amazônia brasileira
(Universidade Federal do Pará, 2014-04-03) CAMARGO, Sofia Lins Leal Xavier de; CARVALHO FILHO, Fernando da Silva; http://lattes.cnpq.br/7987049452090800; ESPOSITO, Maria Cristina; http://lattes.cnpq.br/2112497575917273
Description and comparative morphological notes of female terminalia of species of Peckia Robienau-Desvoidy, 1830 (Diptera, Sarcophagidae) from the Brazilian Amazon. In order to contribute and allow specific identification of female of the genus Peckia, the terminalia of 15 species that occurs in Brasilian Amazon are described, illustrated and an identification key to females is given. Besides gena color and the presence of setulae in gena and calypter, the shape of spermathecae and tergite 6 can also be used in the subgenus determination. The sternites 6, 7 and 8, the position of spiracle 6 and the microtrichosity of tergite 6 reveled important to specific identification. The tergite 8 is present only in the species Peckia (Pattonella) intermutans (Walker, 1861). The shape of vaginal plate, a structure present only in four species of subgenus Peckia, differs in shape and can be used to characterize these species. Therefore, a combined analysis of these features of female terminalia is necessary in the species determinationof the females of Peckia. Peckia (Peckia) hilifera (Aldrich, 1916) is recorded for the first time from Brazil.
Acesso aberto (Open Access)
Determinação de alguns parâmetros da biologia reprodutiva e produtiva da paca fêmea (Agouti paca Linnaeus, 1744) criada em cativeiro
(Universidade Federal do Pará, 2002) LAMEIRA, Ana Paula Guimarães; GUIMARÃES, Diva Anelie de Araújo; http://lattes.cnpq.br/2891287458034896; OHASHI, Otávio Mitio; http://lattes.cnpq.br/5547874183666459
This work had the objective of estimating basics reproductive characteristics of Agouti paca reared in captivity, the determination of the oestrous cycle period, gestational period, parturition interval, first postparturition oestrous, number of offsprings and sexual proportion. The observations were done using a colony of 13 caged animais in the Biotério of Universidade Federal do Pará, and the data were obtained with colpocitological techniques. These results indicate that this specie is polyestrous with continous reproduction. The oestrous cycle was categorized in four phases: proestrous, oestrous, metaestrous and diestrous, and its period was 32,5 ± 3,69 days (n = 20). As for the gestation period, two results were obtained: a) 147, 5 ± 2,83 days (n = 2) for females that had its last oestrous registered with sperm presence and, b) 146,7 ± 6,43 days (n = 3) for females that had just the last oestrous before the parturition. New borns were observed and weights and sexes were registered. Their weight was 605,9 ± 87,47 g (n = 12) for females and 736,7 ± 108,41 g (n = 14) for males. At birth the youngs are quite developed and soon show active movements, opened eyes, body completely covered by hair, and a capacity to eat solids within two days. From 38 births occurred at Biotério, all of them are single, although the A paca is been able to produce more than one offsprings per parturition. The parturition interval was 187,3 ± 8,48 days (n = 15) and within 35,6 ± 5,22 days (n = 5) occurred the first oestrous postparturition. These results can be used as basic orientation to future works with proposes to study reproductive parameters from selvage animals using biothecnology. In addition to, the application of an appropiate management in A. Paca creation, can become in the future, aliment qualified source and lucrative source too. Furthermore, it can give guaranty of species conservation yet.
Acesso aberto (Open Access)
Distribuição espacial de anuros e lagartos ao longo de gradientes ambientais em uma floresta de terra firme na Amazônia oriental, Pará, Brasil
(Universidade Federal do Pará, 2008-08-18) GOMES, Jerriane Oliveira; ÁVILA-PIRES, Teresa Cristina Sauer de; http://lattes.cnpq.br/1339618330655263
This study aims to investigate the relationship between anuran and lizard communities, as well as of some individual species, with leaf litter depth, total basal area of trees, understorey vegetation density, and canopy cover. Sampling occurred between August and November 2007, in a 25 km² grid implanted by the ‘Programa de Pesquisa em Biodiversidade’ (Biodiversity Research Program - PPBIO) / Amazônia, located in the Floresta Nacional de Caxiuanã, Pará, Brazil. Two sampling methods were used: active search and pitfall traps with drift fences. A total of 892 lizard and anuran individuals, of 27 species (15 anuran and 12 lizard species), were recorded. Twelve anuran species (101 individuals) and 12 lizard species (171 individuals) were registered through active search, whereas 11 anuran species (327 individuals) and 15 lizard species (293 individuals) were captured by pitfall traps. No significant relationship was found between distribution of anuran and lizard communities with environmental predictors, indicating that these species occur throughout all studied environmental gradients. Only the lizards Coleodactylus amazonicus and Ptychoglossus brevifrontalis were significantly associated with understorey vegetation density and leaf litter depth, respectively. This study is expected to contribute to the improvement of the research design for the herpetofauna within PPBIO.
Acesso aberto (Open Access)
Diversificação morfológica e molecular em lagartos Dactyloidae sul-americanos
(Universidade Federal do Pará, 2015-03-30) D’ANGIOLELLA, Annelise Batista; CARNAVAL, Ana Carolina de Queiroz; http://lattes.cnpq.br/1268469210243345; PIRES, Tereza Cristina Ávila; http://lattes.cnpq.br/1339618330655263
Acesso aberto (Open Access)
Doadores de sangue positivos em triagem sorológica para doença de Chagas no Acre: necessidade de adequação e orientação diagnóstica
(Universidade Federal do Pará, 2011-01-24) SILVA, Pablo Rodrigo de Andrade e; PÓVOA, Marinete Marins; http://lattes.cnpq.br/2256328599939923
This study, which involved 77,893 blood donors who attended for the first time the Blood Center of Acre, from January 1997 to December 2008, aimed to: 1) to identify individuals with positive serology for Chagas disease, 2) characterize clinically, individuals with positive serology for Chagas' disease and 3) properly orient individuals serologically positive for therapy advocated. The sample consisted of 91.6% of male patients, with an average age around 47, all residents of the state of Acre. Serological screening was performed with the application of the ELISA positive results with 102 of these, 12 were included and subjected to confirmatory testing, of whom 11 had confirmed the positive result. According to the evaluation of complementary exams (ECG, echocardiography and endoscopy), a donor had installed the cardiac and the other an indeterminate form of the disease. You must provide the confirmatory test for Chagas disease in the routine of blood banks in order to ensure timely referral to a qualified medical assistance to that blood donor who became Chagas’ patients.
Acesso aberto (Open Access)
Early Pleistocene lineages of Bagre bagre (Linnaeus, 1766) (Siluriformes: Ariidae), from the Atlantic coast of South America, with insights into the demography and biogeography of the species
(Sociedade Brasileira de Ictiologia, 2016) SILVA, Wemerson Clayton da; MARCENIUK, Alexandre Pires; SALES, João Bráullio de Luna; SILVA, Juliana Araripe Gomes da
Coastal and marine environments are characterized by a lack of evident physical barriers or geographic isolation, and it may be difficult to understand how divergence can arise and be sustained in marine environments. The identification of 'soft' barriers is a crucial step towards the understanding of gene flow in marine environments. The marine catfishes of the family Ariidae are a demersal group with restricted migratory behavior, no pelagic larval stages, and mechanisms of larval retention, representing a potentially useful model for the understanding of historical processes of allopatric speciation in the marine environment. In the present study, two lineages of the Coco sea catfish, Bagre bagre , were recognized from their complete segregation at both mitochondrial and morphological levels. One lineage is distributed between Venezuela and the northern coast of Brazil, including the semiarid northeast coast, while the second lineage is found on the eastern coast of Brazil, including the humid northeast coast. Based on distribution area, habitats preference, and genetic variability, inferences are made in relation to biogeography and demography of lineages in Atlantic coast of South America.
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)
Efeitos ecológicos e evolutivos nos padrões de diversidade de aves na Amazônia
(Universidade Federal do Pará, 2018-09-20) ALMEIDA, Sara Miranda; SANTOS, Marcos Pérsio Dantas; http://lattes.cnpq.br/7941154223198901
Studies covering phylogenetic and functional diversity have been increasingly used to explain patterns of species diversity and organization of biological assemblages, constituting complementary tools to the traditional taxonomic approach (e.g. species richness). Biogeographical knowledge may also contribute to the understanding of these patterns, since the geographical distribution of different taxa depends on historical processes related to dispersion and speciation, in this manner influencing the formation of regional pools of species. In this thesis we evaluated the influence of historical processes and environmental factors on the diversity of Amazon bird assemblages. We compiled compositional data from 80 bird assemblages, 12 in savannas and 68 in terra firme forests, totaling 878 species. In Chapter 1 we evaluated the phylogenetic and functional diversity of passerine birds (Passeriformes order) considering two factors: the biogeographical history of each suborder (Passeri and Tyranni) and the habitat type (forest and savanna). We verified the importance of the different habitats for the maintenance of bird diversity since, although Amazonian savannas present low species richness when compared to forests, this habitat presents assemblages with unique combinations of ecological traits and specific lineages. We showed through the results found in this chapter that the greater functional diversity of Passeri assemblages in both habitats and the greater phylogenetic diversity of Tyranni in terra firme forests are related to the biogeographic history of each suborder and their adaptation to the habitat. In Chapter 2, we assessed the contribution of Amazonian biogeographic regions (a.k.a., endemism areas) and climatic variables to species composition and to the phylogenetic structure of canopy and forest understory bird assemblages. We hypothesized that differences in species composition are greater between interfluves for understory bird assemblages, which are composed of species with lower dispersion capacity, than for canopy birds. In this chapter, we found that the understory bird assemblages were more influenced by biogeographic barriers than canopy birds, corroborating our hypothesis. The climatic variables were important to explain the species diversity and phylogenetic structure of both groups. With the results generated in this thesis I concluded that the Amazonian bird diversity is result of processes related to biogeographic history, ecological traits of species, and environmental conditions.
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Estudo comparativo das espécies de Saimiri voigt, 1831 (Primates, Cebidae) na reserva Mamirauá, Amazonas
(Universidade Federal do Pará, 2008-05) PAIM, Fernanda Pozzan; QUEIROZ, Helder Lima de; http://lattes.cnpq.br/3131281054700225
One of the ten primate species found at Mamirauá Reserve (RDSM) is Saimiri vanzolinii that have the boundaries of distribution hitherto not defined. The distribution area of S. vanzolinii is considered the smallest among neotropical primates species, about 950km². Two other forms of Saimiri occur at the region, but their taxonomic status has not been determined yet. The aim of this study was to establish ecological and behavioural characteristics that might act as causes for reproductive isolation among the Saimiri forms at the Mamirauá Reserve area. Several sample areas were surveyed, near to both river banks and channels that coincide with the boundaries of the geographic distribution of S. vanzolinii. Geographic coordinates were recorded each five minutes of the way with a GPS. For each site where a social unit of Saimiri was found some additional information was registered such as the locality, number of individuals, habitat type, water marks on the trees, and other primate species associated with the squirrel monkeys. The “cackle” vocalization was recorded whenever possible. The total distance surveyed was 218 km, where 328 social units of the genus Saimiri were recorded: 41% of Saimiri vanzolinii, 30% of Saimiri sp.1 and 29% of Saimiri sp.2. One of the limits of distribution (western-northwestern) of S. vanzolini was confirmed. This species were absent from two areas where their presence was previously believed. Sympatric and syntopic areas were also observed. The area in use by Saimiri vanzolinii was 106 km², smaller than previously known, occupying only 870 km², it corroborated that hypothesis that Saimiri vanzolinii have the smallest distribution among the neotropical primate species. The most important results of this study that might determine the reproductive isolation among Saimiri forms are the differential habitat use types (habitat selectivity), size of their social units, discrepancy between use of vertical strata and high initialisation frequencies for the “cackle” vocalization. Saimiri vanzolinii shows preference for the “chavascal” habitat on both sazonal extremes (dry and wet seasons), meanwhile Saimiri sp.1 and Saimiri sp.2 shows preference for the low varzea habitats. The average size of the social unit Saimiri sp.2, at the dry season was smaller than of the other forms. In terms of the the vertical strata use, Saimiri vanzolinii occupied lower levels in the dry season, as Saimiri sp.1. All forms occupied lower strata during the wet season. The initialization frequencies of “cackle” vocalization showed differences among the three groups, where Saimiri vanzolinii < Saimiri sp.1 < Saimiri sp.2. The results suggest that ecological segregation of Saimiri vanzolinii from the other forms occur mostly by the habitat partitioning. The medium size of the social unit of Saimiri sp.2 suggests that this species is ecologically different from the other forms. Differences between Saimiri sp.1 and Saimiri sp.2 were observed on the size of their social units, vertical use of space and high “cackle” vocalization initialisation frequencies. The areas where the Saimiri forms are present in the focal Mamirauá Reserve area probably show different paleogeographic histories, offering distinct resources for each taxon. Field studies about vegetation aspects, geoprocessing and feeding ecology must be carried out in the area to allow the understanding of the ecological and behavioural differences that could act upon the distribution of Saimiri and other primate species.