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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.
61

Caracteriza??o do repert?rio ac?stico do botocinza, sotalia guianensis, e impacto de embarca??es no nordeste do brasil

Martins, Dalila Teles Le?o 26 April 2010 (has links)
Made available in DSpace on 2014-12-17T15:36:59Z (GMT). No. of bitstreams: 1 DalilaTLM_DISSERT.pdf: 2036255 bytes, checksum: ed8754e17f7a4951187f5fb000aa8918 (MD5) Previous issue date: 2010-04-26 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The wide distribution along the Brazilian coast of specie Sotalia guianensis has been growing interest in searchers on the ecology of this species, addition to commercial interests by whalewatching. This work described the accoustic repertory of S. guianensis and their behavior associated and found if underwater noises affect this repertorie in Pipa-RN. It were analyzed 18:49h of recordings maked between april and june/2009. It were found 3258 whistles, 289 calls, 873 clicks and no gargle. The frequencies range of guiana dolphins was 1 a 48kHz and may be related to system response recorder and population s regionalization. The frequencies overlaps the noise made by motorboats, schooners and water bomb. The behavior travelling ocurred siletly in 72,58% and socialization presented no sound (56,4%) and presence of sound (43,6%). This great absence of sound may be relacioned to saving energy, probably because in this behaviors they can use physical and visual contacts. The foraging presented highest records of all class noise with 46,84% clicks, 33,84% whistles and 9,02% calls. All this sounds occurred differently in each behavior (travelling: x2 = 134,35 df = 3 p = 0,0001; foraging: x2 = 19,83 df = 3 p= 0,00018 and socialization x2 = 60,35 df = 3 p = 0,0001). It was possible to determine that underwater noise cause changes in the repertorie and does a considerable increase in whistle s number and reduce clicks. Also occurs changes in some whistles (FI: t=2,42, p=0,015; FF: t= -2,22, p=0,025), calls (FMI: t= -3,13, p=0,001; FMA: t= -3,49, p=0,0005; FD: t= -2,21, p=0,027; D: t=2,89, p=0,004) and clicks parameters (D: t= -3,85, p=0,0001; I: t= -5,32, p=0,0001) during presence of noise. These changes may be a strategy of these animals to win this sound barrier. We can not say which noise has more impact, ix however the water bomb seems to affect more the clicks and the motorboats seems to affect the others sounds. Little is know about auditive sensibility of this specie, but daily exposure to this noise may cause damage and this specie appears to have residence. The specie conservation is necessary because the population already seems to suffer damage as decrease in length of stay, number of individuals entering the inlet and the apparent diminution in the foragind during vessels presence and control standards and ambiental education can help. So, we can advance in knowledge about the ecology of this specie especially when it come to bioacoustics and their behaviors associated and reveals some of the impacts that the noise have brought to this population / A ampla distribui??o na costa brasileira da esp?cie Sotalia guianensis tem feito crescer o interesse pelos pesquisadores sobre a ecologia dessa esp?cie, al?m de interesses comerciais atrav?s do turismo de observa??o. Esse trabalho descreveu o repert?rio ac?stico S. guianensis e suas associa??es comportamentais e ainda, verificou se ru?dos subaqu?ticos de motores afetam o padr?o desse repert?rio, na regi?o de Pipa/RN. Foram analisadas 18:49h de grava??es realizadas entre os meses de abril e junho de 2009. Foram encontrados 3258 assobios, 289 gritos, 873 sequ?ncias de estalos e nenhum registro de gargarejo. A faixa de frequ?ncia dos botos variaram de 1 a 48kHz, que pode estar relacionada com a taxa de amostragem de 96kHz e com a regionaliza??o das popula??es. Essa faixa se sobrep?e as faixas utilizadas pelos ru?dos produzidos por lanchas, escunas e uma bomba d ?gua. Nas associa??es comportamentos e ac?stica, o estado de deslocamento ocorreu em 72,58% com aus?ncia de som e a socializa??o apresentou aus?ncia (56,4%) e presen?a de sons (43,6%). Essa aus?ncia de som pode estar relacionada com a economia de energia, visto que nesses comportamentos muitos eventos envolvem contatos f?sicos e visuais. A alimenta??o apresentou os maiores registros de todas as classes sonoras, com 46,84% de estalos, 33,84% de assobios e 9,02% de gritos. Todos os sons ocorreram com diferen?as significativas dentro de cada estado comportamental (deslocamento: x2 = 134,35 df = 3 p = 0,0001; alimenta??o: x2 = 19,83 df = 3 p= 0,00018 e socializa??o x2 = 60,35 df = 3 p = 0,0001). Com rela??o aos ru?dos, foi poss?vel verificar que esses sons causam modifica??es na vocaliza??o, com aumento consider?vel no n?mero de assobios e redu??o dos estalos. Ocorre, tamb?m vii altera??es de alguns par?metros dos assobios (FI: t=2,42, p=0,015; FF: t= - 2,22, p=0,025), gritos (FMI: t= -3,13, p=0,001; FMA: t= -3,49, p=0,0005; FD: t= -2,21, p=0,027; D: t=2,89, p=0,004) e estalos (D: t= -3,85, p=0,0001; I: t= -5,32, p=0,0001) durante a presen?a desses sons. Essas modifica??es podem ser uma estrat?gia que essa popula??o est? desenvolvendo para vencer a barreira dos ru?dos. N?o se pode afirmar qual dos tr?s ru?dos analisados causa maior impacto, entretanto a bomba d ?gua parece afetar mais os estalos, aumentando os valores de seus par?metros e a lancha parece afetar mais as outras classes sonoras. Pouco se sabe sobre a sensibilidade auditiva dessa esp?cie, mas exposi??es di?rias aos ru?dos podem trazer danos e essa esp?cie aparenta ter resid?ncia. Medidas para mitiga??o, como normas de controle das embarca??es e educa??o ambiental s?o necess?rias para a conserva??o da esp?cie, visto que a popula??o j? aparenta sofrer com danos como diminui??o do tempo de perman?ncia e n?mero de indiv?duos que entram na enseada, al?m da aparente diminui??o da alimenta??o durante a presen?a de embarca??es. Dessa forma, avan?a-se no conhecimento sobre a ecologia dessa esp?cie, principalmente quando se trata de bioac?stica e suas associa??es comportamentais, al?m de revelar alguns dos impactos que os ru?dos tem trazido para essa popula??o
62

Encalhes de Cet?ceos ocorridos no per?odo de 1984 a 2005 no litoral do Rio Grande do Norte, Brasil

Medeiros, Priscila Izabel Alves Pereira de 03 July 2006 (has links)
Made available in DSpace on 2014-12-17T14:02:03Z (GMT). No. of bitstreams: 1 PriscilaIAPM.pdf: 1776950 bytes, checksum: 9b264328a0abdee8b5b1062e77c5928c (MD5) Previous issue date: 2006-07-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Strandings of live or dead aquatic mammals constitute an important instrument to provide information regarding the occurrence, biology and ecology of these species. The aim of this study was to register the stranded species of cetaceans, the frequency and the spatial-temporal distribution of theses strandings during the period of 1984 to 2005, in the coast of Rio Grande do Norte. Data was acquired through the monitoring of strandings in the north, north-west and south coast of RN, and through information obtained from institutions and newspaper archives of the State. A total of 122 strandings of cetaceans were registered along the coast of Rio Grande do Norte. Of the 14 species of cetaceans registered, four species had higher frequencies: Sotalia guianensis (n= 65), Steno bredanensis (n = 6), Globicephala macrorhynchus (n = 6) and Physeter macrocephalus (n = 7). Out of 118 strandings, 93 occurred in the south coast (78.8 %), 23 in the north coast (19.5%) and 2 (1.7%) in the north-west coast of the State. The highest frequency of strandings occurred during the months of August to March and the maximum number of strandings occurred from 2000 onwards, as a consequence of the intense monitoring of the Pequenos Cet?ceos Project in Rio Grande do Norte / Os encalhes de mam?feros aqu?ticos vivos ou mortos consistem em um instrumento importante na obten??o de informa??es sobre a ocorr?ncia, a biologia e a ecologia das esp?cies. O objetivo do presente trabalho foi registrar as esp?cies de cet?ceos encalhadas, a freq??ncia e a distribui??o espa?o-temporal destes encalhes, durante o per?odo de 1984 a 2005 no litoral do Rio Grande do Norte. Os dados foram coletados atrav?s do monitoramento de encalhes de cet?ceos no litoral norte, noroeste e sul do RN, e atrav?s do levantamento de informa??es sobre encalhes em institui??es e arquivos dos jornais do Estado. Um total de 122 cet?ceos encalhados foi registrado ao longo do litoral do Rio Grande do Norte. Foram registradas 14 esp?cies de cet?ceos, das quais quatro esp?cies apresentaram maior freq??ncia: Sotalia guianensis (n = 65), Steno bredanensis (n = 6), Globicephala macrorhynchus (n = 6) e Physeter macrocephalus (n = 7). Dentre 118 eventos de encalhes, 93 ocorreram no faixa sul (78,8 %), 23 na faixa norte (19,5%) e dois (1,7%) na faixa noroeste do Estado. A maior freq??ncia de encalhes ocorreu entre os meses de agosto a mar?o e o m?ximo n?mero de encalhes foi registrado a partir de 2000, como uma conseq??ncia do intenso monitoramento realizado pelo Projeto Pequenos Cet?ceos do Rio Grande do Norte
63

Ecology of the Guiana dolphin (Sotalia guianensis) in the Southern area of the Gulf of Morrosquillo, Colombia : implications for conservation

Dussán-Duque, Beatriz Salomé January 2013 (has links)
Sotalia guianensis is listed as “Data Deficient” by the IUCN and as “Vulnerable” in Colombia. This study aimed to advance understanding of the ecology of this species and its habitats, and to provide information to conservation management in the southern Gulf of Morrosquillo, Colombia. Systematic boat-based surveys were conducted during 395 days in 2002-2006 and 2009-2010, following established routes. Total survey effort was 15,199 km in an area covering ~ 310km². Fine scale habitat use and behavioural modelling, photo-identification and mark-recapture techniques were used to analyze the ecological patterns for this species. The most recent abundance estimate of dolphins using the study area during dry and rainy seasons, varied from 225 (CV = 0.34; 95% CI: 118-426) to 232 (CV = 0.32; 95% CI: 127-246). Annual survival rate is estimated at 0.948 (95% CI = 0.876-0.980). Overall density was 0.74/km². Dolphins were present year-round in the whole study area. Results indicate that they do not use the study area uniformly and that the use of particular zones is related to eco-geographic variables. Dolphins showed a preference for waters greater than 3m in depth with a slightly increased preference for waters about 5m and 15-25m deep. The average group size was nine individuals. Some individuals show long-term high site fidelity to some zones within the study site boundaries. Even though the site fidelity to feeding areas varied individually, all the individuals focused primarily on one specific area. Foraging was among one of the most predominant behaviours observed. The individual movements show that some dolphins use both bay and gulf waters. Dolphins show a range of surface cooperative foraging and feeding strategies. These cooperative behaviours were influenced by zone, group size and prey type. Based on these results an area of special management for the species will be created in Colombia.

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