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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

ECOLOGIA DE TRÊS ESPÉCIES SIMPÁTRICAS DE VIPERÍDEOS (SERPENTES: VIPERIDAE) NO PARQUE ESTADUAL DO TURVO, RIO GRANDE DO SUL, BRASIL / ECOLOGY OF THREE SYMPATRIC PITVIPER (SNAKES: VIPERIDAE) IN PARQUE ESTADUAL DO TURVO, RIO GRANDE DO SUL, BRAZIL

Rocha, Marcelo Carvalho da 30 August 2010 (has links)
At Parque Estadual do Turvo, an area of atlantic forest in the northwest of Rio Grande do Sul, Brazil, was recorded in sympatry by different sampling methods three viperids species. Bothropoides diporus the snake was more common, and also the best adapted to dry and degraded areas (64.95% of total), Bothropoides jararaca (21.65%), was sampled in degraded areas and inside forest, was the only one be sampled perched and Bothrops jararacussu (13.40%) was restricted to forested areas, particularly near water bodies. The offspring of B. jararaca and B. jararacussu inhabit the streams. Compared by a multiple linear regression the number of monthly meetings of snakes with the following variables: average monthly minimum temperature, monthly rainfall and monthly insolation during the study period. Significant difference between the number of snakes caught between the stations of the largest and lowest temperatures. There was no significant difference in the daily activity of snakes. The diet of B. diporus and B. jararaca is composed of mammals, amphibians and reptiles, and mammals the item most used by both species was not observed differences in diet between males and females of B. diporus, showed had specialized diet in mammalian, was not observed shift ontogenetic diet B. jararaca. The method provided the best results was local collectors (65.99%) followed by occasional encounters (17.53%), time constrained search (12.37%), search in roads (4.12%). Pitfall traps with drift fences were not successful in viperids in this study / No Parque Estadual do Turvo, uma área de mata atlântica no Noroeste do Estado do Rio Grande do Sul, Brasil, foram registrados em simpatria por diferentes métodos de amostragem três espécies de viperídeos. Bothropoides diporus foi a serpente mais comum, sendo também a melhor adaptada em áreas degradadas e secas (64,95% do total), Bothropoides jararaca (21,65%), foi amostrada em áreas degradadas e interior de floresta, foi a única a ser amostrada empoleirada e Bothrops jararacussu (13,40%) ficou restrita às áreas florestadas, sobretudo próxima a corpos d água. Os filhotes de B. jararaca e B. jararacussu habitam os riachos. Comparamos por uma regressão múltipla linear o número mensal de encontros de serpentes com as seguintes variáveis ambientais: temperatura média mínima mensal, pluviosidade mensal e insolação mensal durante período do estudo. Houve diferença significativa entre o número de serpentes capturadas entre as estações de maiores e menores temperaturas. Não houve diferença significativa na atividade diária das serpentes. A dieta de B. diporus e B. jararaca é composta de mamíferos, anfíbios anuros e répteis, sendo mamíferos o item mais utilizado por ambas as espécies, não foi evidenciado diferenças na dieta de machos e fêmeas de B. diporus, que mostrou-se especialista em mamíferos nem variação ontogenética na dieta de B. jararaca. O método que proporcionou os maiores resultados foi auxílio de terceiros (65,99%) seguido de encontros ocasionais (17,53%), procura visual limitada por tempo (12,37%), procura em estradas (4,12%). Armadilhas de interceptação e queda não foram eficientes para viperídeos neste estudo.
2

Habitat Use And Seasonal Activity Of Selected Snakes On John F. Kenned

Dyer, Karen 01 January 2004 (has links)
An intensive, replicated monthly sampling of snake communities inhabiting four habitat types was conducted at John F. Kennedy Space Center, Brevard County, Florida from November 2002 through October 2003. Thirteen species (580 individuals plus 74 recaptures) plus one hybrid were captured. The three most commonly captured species, Coluber constrictor, Thamnophis sirtalis, and Thamnophis sauritus, combined made up 85% of the sample. These three species were active during every month of the year, but showed modal activity patterns typical of Temperate Zone snakes. Monthly snake captures were correlated with monthly captures of potential prey species and with mean monthly temperature. Species richness in the four habitat types varied from nine to 12. Drift fences in ruderal habitats had the highest species richness, while fences in swales captured the greatest number of individuals. The most dissimilar habitat pair was scrub and swale, while the most similar pair was ruderal and hammock. Box traps proved more effective for targeting the largest snake species, while funnel and box traps were equally effective for targeting other species.
3

The Habitat Ecology of Bog Turtles (<i>clemmys Muhlenbergii</i>) in Southwestern Virginia

Carter, Shawn L. 07 August 1997 (has links)
I radiotracked 31 bog turtles (<i>Clemmys muhlenbergii</i>) from May 1995 to December 1996 at 4 study areas in southwestern Virginia. Radio location data were used to provide measures of annual activity, spatial distributions of animals, and habitat selection. The techniques I used in this study were as follows: distance measurements between consecutive locations, home range estimators (Minimum Convex Polygon [MCP] and cluster analysis), compositional analysis of habitat selection, and measurement of microhabitat variables. Results suggest a random pattern of movement by bog turtles within habitats. Average net movements recorded between consecutive locations (separated by < 7 days) during 1995 and 1996 measured 15 m and 20 m for females and 14 m and 23 m for males respectively. Eighty-six percent of all net movements (n = 824) were less than 30 m, whereas only 2% were greater than 100 m. In 1996, average home range sizes (95% MCP, 95% cluster) were 0.47 ha and 0.17 ha for females and were 0.57 ha and 0.13 ha for males. Bog turtles selected wet meadow areas and bulrush (<i>Scirpus</i> spp.) patches more than expected randomly and avoided dry meadow areas and streams. Turtles were located more frequently in mud (x = 24.3 cm) and water (x = 5.2 cm) than expected by random selection (P < 0.001). I found no differences between sexes in movement, home range, or habitat selection by bog turtles. Bog turtles select specialized habitat types and microhabitats within wetlands. Large-scale movements are infrequent and the risk of site isolation may be high if wetland habitat loss continues at historic rates. Future management should protect spatially-close sites which contain multiple habitat types, soft substrate, and pockets of water. / Master of Science
4

Migração e movimentos do grumatã (Prochilodus lineatus, Valenciennes, 1836) (Characiformes, Prochilodontidae) no Rio dos Sinos, RS, Brasil, determinados por radiotelemetria

Pesoa, Nicolle Albornoz 30 July 2004 (has links)
Made available in DSpace on 2015-03-05T16:19:36Z (GMT). No. of bitstreams: 0 Previous issue date: 30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O conhecimento da estratégia de vida, estrutura populacional e comportamento são fundamentais para a compreensão da biologia dos peixes e imprescindíveis para a elaboração de planos de conservação. Prochilodus lineatus é uma espécie reofílica, migradora, com grande biomassa e considerada relevante economicamente. Com ampla distribuição nas bacias do Brasil, vem sofrendo uma redução na densidade populacional devido o impacto antrópico como diminuição das áreas de desova, rotas migratórias afetadas pôr barragens e construções de usinas e por pesca intensiva. Através da utilização da radiotelemetria foram investigadas as migrações, o habitat de estadia, a atividade diária e sazonal e estabelecimento do período reprodutivo. De Agosto de 2002 a Março de 2004, 19 grumatãs foram marcados com rádio-transmissores (149.640MHz, 320 dias de vida, LOTEK Canadá Ltda.) na cavidade peritoneal. Semanalmente os peixes foram rastreados, usando barco ou avião. O monitoramento através de estações fixas foi permanente. Cada estaçã / Life strategy, population structure and behavior are fundamental elements for the comprehension of fish biology and essential for conservation. The grumatã, (Prochilodus lineatus; Prochilodontidae) is a reophilic migratory species of economical importance for local fisheries. It is widely distributed in Brazil. During the last decades grumatã populations seem to have declined due to river damming by power plant constructions, pollution, habitat degradation and heavy fishing pressure. The present study investigated circadian and seasonal activity patterns, spawning migration and habitat use. Between August 2002 and March 2003 nineteen Grumatã were tagged internally with digitally coded radio transmitters (149 MHz). Mobile tracking was carried out weekly by boat or aircraft. Additionally six data loggers recorded movements of tagged fish. Results showed that the mean distance covered per fish and day was positively related with fish weight (r2 =0.3102; p=0.013). Grumatã showed a preference for river reaches su
5

Intégrer les effets de la météorologie dans la modélisation de l'activité et de la survie des populations de tiques Ixodes ricinus dans le contexte du changement climatique / Integrating the effects of weather factors in the modeling of the survival and activity in Ixodes ricinus tick populations in the context of climate change

Cat, Julie 28 February 2017 (has links)
La tique Ixodes ricinus est un vecteur de maladies chez l’animal et chez l’Homme d’importance majeure en Europe. Le réchauffement climatique modifiera probablement son profil temporel d’activité. Pour l’évaluation présente et future du risque de piqûre par I. ricinus, des modèles météo-sensibles de prédiction de l’activité sont nécessaires. Dans cette thèse un modèle météo-sensible de régression linéaire généralisé a été ajusté sur des séries temporelles de captures de nymphes, acquises antérieurement à la thèse, pour prédire l’activité saisonnière des nymphes. Depuis ce modèle des profils saisonniers ont été simulés sous scénario de changement climatique. Un modèle de survie météo-sensible a été ajusté à des durées de survie chez des adultes femelles I. ricinus dans un cadre bayésien. Simultanément à la modélisation, nous avons investigué les profils d’activité saisonnière des nymphes I. ricinus sur plusieurs observatoires répartis dans les climats de France métropolitaine par des captures mensuelles en continu d’avril 2014 à juillet 2016. Le comportement d’I. ricinus sous des conditions informatives pour le changement climatique a été investigué. Nos observations et nos simulations confortent l’hypothèse d’une augmentation progressive de l’activité d’I. ricinus sur la saison d’hiver, avec des pics d’activité plus précoces. Une activité modérée a été mise en évidence sous des vagues de chaleur à certains moments du jour, suggérant l’importance de l’échelle infra-journalière en été. Le modèle de survie a reproduit avec succès l’effet très défavorable des conditions sèches sur la survie des femelles. Notre travail de thèse souligne l’importance i) d’acquérir des observations au plus proche des futures conditions saisonnières, ii) de renforcer la sensibilité des modèles de dynamique de populations à la disponibilité en eau dans le milieu des tiques, iii) d’étudier les effets de la météorologie vécue sur la population à l’échelle inter‑annuelle. / The tick species Ixodes ricinus is a vector of major concern for animal and public health in Europe. Climate change will probably modify its activity time patterns. In the present and future bite risk assessment, weather-based models are required to predict tick activity. In this work a weather-based generalized linear regression model was fitted to tick count time series to predict the seasonal activity in I. ricinus nymphs. Using this model we simulated activity time series with climate change weather time series as inputs. A weather-based model was fitted to survival durations in I. ricinus females using a Bayesian estimation method. Simultaneously to modeling, we settled several observatories located in the climate areas encountered in mainland France to investigate the seasonal activity patterns of I. ricinus populations. Monthly tick collection was performed in routine from April 2014 to July 2016. I. ricinus behavior was investigated under conditions which are informative to assess the impact of climate change on activity. Both our observed and simulated results reinforce the hypothesis that activity periods will spread over winter under climate change. In summer season, activity was moderately high at some moments of the day, which underlined that the intra-day scale should be considered when assessing summer activity. The survival model successfully simulated the critical effect of dryness on female survival. In this work we highlighted the need i) to acquire observations under present conditions which are close to the ones projected under climate change, ii) to strengthen the sensitivity of population dynamic models to water availability in the close environment of ticks, and iii) to investigate the effects of the weather conditions undergone by ticks on their population dynamics at the inter-annual scale.

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