95 resultados para lek


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ethnobiology studies Local Ecological Knowledge (LEK) as well as the use and management of natural resources by local communities in order to understand how the environment is perceived, known and classified by human groups. In fishing communities, LEK adds empirical information about the biology of aquatic species and complements scientific findings, especially when it is difficult to obtain factual information during studies on cetaceans, whose behavior is essentially underwater. Cetaceans (whales and dolphins) are constantly threatened by human activities, especially by accidental capture of small coastal species, as in the case of the estuarine dolphin (Sotalia guianensis), object of this study. Ethnobiological researches in fishing communities are of great importance and can clarify aspects of the biology and conservation of this species. Although extensively studied throughout its distribution range, there are still gaps in the knowledge about S. guianensis. Therefore, fishers local ecological knowledge becomes an additional tool to get and confirm information about S. guianensis. This study evaluated the LEK of artisanal fishers who are daily exposed to local population of S. guianensis, through the use of semistructured interviews (N=116). The interviewed fishers were asked about the biology and popular classification of S. guianensis and about possible interactions between this dolphin and them. The studied communities were located in Tibau do Sul (n=39), Pipa (n=36) and Baía Formosa (n=41), all on the south coast of Rio Grande do Norte, Brazil. The study was based on the assumption that differences in fishers LEK among those communities would be caused by both the variety of fishing environments (lagoon/estuary and ocean) and the intensity of tourism activities. Fishers knowledge is expressive and differed among the studied communities depending on the topic investigated. Fishers correctly reported the habitat, distribution, seasonality and behavioral particularities of S. guianensis. Tourism mainly affected the naming of the species. The study results also suggest that marine fishers have greater knowledge about the species than the estuarine/lagoon ones. Local populations accumulate empirical knowledge according to their environment. Hence, it is important to take into account both empirical knowledge and popular participation in management systems, in order to maintain information sharing among communities

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The knowledge of Anastrepha zenildae behavioral aspects combined with the biology of Tephritidae may contribute to monitoring and control programs of this fruit fly that is considered as economically important to the Rio Grande do Norte state. In order to characterize the daily activity profile of this species, we studied the behaviors of resting, locomotion, feeding, cleaning, courtship, copulation and oviposition of animals submitted to an artificial 12:12h light-dark cycle (750:1lux) with controlled temperature (26±2 °C). The observations were made with groups of 16 males and 16 females during 3 consecutive days each generation from parental to F5. Resting, locomotion, feeding and cleaning data were recorded as frequency and time of occurrence by scanning technique in 15 minutes windows per hour, with a record each minute. Courtship, copulation and oviposition were recorded as frequency, time of occurrence and duration by al occurrences technique. Resting was the most frequent behavior with males resting more than females. Locomotion was more evident in the first half of the ligh phase with higher values in females. Cleaning and feeding behaviors were more frequent in the second half of the light phase for both sexes with females eating more frequently than males. During the courtship, males were grouped in lek formations showing wings vibration and pheromone liberation. Courtship occurred more frequently 4 to 7 h after lights on (81,9%) with copulations being more frequent 6 h after lights on with a mean duration of 58,1±40,4 min. Copulation attempts were observed in males inside and outside the lek with aggressive behavior being observed only between males in the lek. Oviposition behavior was similar to that described for other species of the genus with a peak of this activity 2-3 h after the lights on, mean duration of 43, 7±34, 8 sec and 2 to 5 eggs by event. According to the results, sexual behavior of A. zenildae is temporally different of other sympatric species of the genus, being favorable to the reproductive isolation as well as the use of resources as oviposition substrate.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The present study describes the reproductive biology of Scinax fuscomarginatus in a remnant of Cerrado in south-eastern Brazil. Observations were made between September 2002 and March 2004 at Estacao Ecologica de Itirapina, State of São Paulo, south-eastern Brazil. Breeding activities occurred in lentic and temporary bodies of water during the rainy season. Scinax fuscomarginatus exhibited a prolonged breeding pattern and a lek mating system. Males were smaller than females and defended individual calling areas through acoustic and physical interactions. Resident males consistently won encounters, but did not differ in size or mass from intruder males. Satellite behaviour was observed, but no female or amplected pair interception was registered. Scinax fuscomarginatus exhibited low operational sex ratios and the general reproductive mode in which eggs are laid in the water and tadpoles are aquatic. Amplexus was axillary and the eggs were deposited at the bottom of temporary ponds. Details on oocytes, egg masses, and eggs are included.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

1. This study aimed to link basic ethnobiological research on local ecological knowledge (LEK) to the conservation of Brazilian streams, based on two case studies: original data on LEK of fishermen about freshwater fish in the Negro River, Amazon, and previously published data about LEK of farmers on the ecological relationship between forest and streams in the Macabuzinho catchment, Atlantic Forest.2. Information was obtained from fishermen through interviews using standard questionnaires containing open-ended questions. Informants for interview were selected either following some defined criteria or applying the 'snowball' method.3. Fishermen's LEK about the diets and habitats of 14 fish species in the Negro River provided new biological information on plant species that are eaten by fish, in addition to confirming some ecological patterns from the biological literature, such as dependence of fish on forests as food sources.4. In the Atlantic Forest, a comparison between farmers' LEK and a rapid stream assessment in the farmers' properties indicated that farmers tended to overestimate the ecological integrity of their streams. Farmers recognized at least 11 forest attributes that correspond to the scientific concept of ecosystem services. Such information may be useful to promote or enhance dialogue among farmers, scientists and managers.5. These results may contribute to the devising of ecosystem management measures in the Negro River, aimed to conserve both rivers and their associated floodplain forests, involving local fishermen. In the Atlantic Forest, we proposed some initiatives, such as to allow direct economic use of their forests to conciliate conflicting perceptions of farmers about ecological benefits versus economic losses from reforestation. Despite their cultural, environmental and geographical differences, the two study cases are complementary and cost-effective and promising approaches to including LEK in the design of ecological research. Copyright (C) 2007 John Wiley & Sons, Ltd.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Males of Xylocopa fimbriata and X. micans present mesosomal glands that produce secretions containing many volatile substances with an intense floral fragrance, which resembles the fragrance produced by flowers that are attractive to the females of both species. The mating territories occupied by males of X. frontalis have no helpful resources for the females of this species, which are probably attracted to these environments by sexual pheromone(s) produced in the male mesosomal glands (lek polygyny). In this work, the presence of these glands in males of X. frontalis was confirmed and their anatomy and ultrastructure were described. An attempt to correlate the morphological characteristics of the mesosomal glands with the male territorial behavior was also carried out.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A comunicação acústica em beija-flores durante muito tempo foi negligenciada em função da coloração conspícua que representa uma sofisticada comunicação visual da maioria dos representantes deste grupo. Entretanto, estudos recentes constataram que há indícios de aprendizagem vocal em algumas espécies de Trochilidae. O presente estudo aborda o comportamento vocal do beija-flor Phaethornis superciliosus, espécie abundante na região amazônica. Esta espécie apresenta como sistema de acasalamento a formação em arena, que consiste na agregação de machos em um pequeno território, onde se exibem para outros machos e fêmeas, com o intuito de atrair estas últimas para acasalar. O objetivo geral deste trabalho foi analisar o comportamento vocal de P. superciliosus dispostos em seis arenas no Parque Ecológico de Gunma, Santa Bárbara do Pará, 50 km ao norte de Belém, considerando a emissão e estrutura física do canto, seu repertório, a frequência de emissão ao longo do dia e do ano e a dinâmica das arenas. Verificamos que a população estudada apresenta um repertório vocal composto de duas notas que são emitidas de maneira alternada. Os cantos dos indivíduos analisados apresentaram diferenças significativas entre si considerando os parâmetros físicos do som (frequências máxima e mínima, duração e intervalo entre as notas e o ritmo de emissão das notas). Esta diferenciação inter-individual pode estar relacionada à seleção sexual, na qual o canto pode permitir o reconhecimento individual, sua posição social e seu desempenho para a atração das fêmeas. Constatamos que a atividade vocal é mais intensa no segundo semestre, entre junho e novembro, período que provavelmente corresponde à estação reprodutiva. Realizamos testes de playback, que consistem em reproduzir um som previamente gravado e registrar a resposta provocada em uma das arenas em dois pontos distintos, simulando a entrada de outro indivíduo. Constatamos que o som emitido em resposta ao teste diferiu significativamente do canto espontâneo em todos os parâmetros físicos analisados. A resposta ao playback mostra que houve uma redução na faixa de frequência com que o canto foi emitido e o ritmo de emissão de notas mais rápido. Tais características do canto podem estarrelacionadas a um comportamento mais agressivo. As arenas são formadas emáreas de borda e sempre próximas a igarapés, com o tamanho da área variando entre 86m2 e 14m2, compostas de dois a quatro indivíduos distantes de 7m a 72m entre si. Nossos resultados mostraram que a organização social da arena deve ser melhor compreendida através de estudos mais detalhados sobre o possível significado que as diferenças individuais no canto podem representar para o estabelecimento da posição hierárquica dos indivíduos nas arenas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coupled analyses of n-alkane biomarkers and plant macrofossils from a peat plateau deposit in the northeast European Russian Arctic were carried out to assess the effects of past hydrology on the molecular contributions of plants to the peat. The n-alkane biomarkers accumulated over 9.6 kyr of local paleohydrological changes in this complex peat profile in which a succession of vegetation changes occurred during a transition from a wet fen to a relatively dry peat plateau bog. This study shows that the contribution of the n-C31 alkane from rootlets to peat layers rich in fine and dark roots is important. The results further indicate that the n-alkane Paq and n-C23/n-C29 biomarker proxies that have been useful to reconstruct past water table levels in many peat deposits can be misleading when the contributions of Betula and Sphagnum fuscum to the peat are large. Under these conditions, the C23/(C27 + C31) n-alkane ratio seems to correct for the presence of Betula and S. fuscum and provides a better description for the relative amounts of moisture. The average chain length (ACL) n-alkane proxy also appears to be a good paleohydrology proxy in having larger values during dry and cold conditions in this Arctic bog setting.