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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

When wolves cry: long distance calling by wild maned wolves

Rocha, Luciana Helena Silva 25 May 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-25T23:08:58Z No. of bitstreams: 1 LucianaHelenaSilvaRocha_DISSERT.pdf: 1669201 bytes, checksum: 3c7d0a6a9b45e9896e7c8ea5f9fd7eef (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-27T23:53:09Z (GMT) No. of bitstreams: 1 LucianaHelenaSilvaRocha_DISSERT.pdf: 1669201 bytes, checksum: 3c7d0a6a9b45e9896e7c8ea5f9fd7eef (MD5) / Made available in DSpace on 2016-04-27T23:53:09Z (GMT). No. of bitstreams: 1 LucianaHelenaSilvaRocha_DISSERT.pdf: 1669201 bytes, checksum: 3c7d0a6a9b45e9896e7c8ea5f9fd7eef (MD5) Previous issue date: 2015-05-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / O lobo-guar? (Chrysocyon brachyurus Illiger 1815) ? o maior can?deo da Am?rica do Sul e encontra-se quase-amea?ado de extin??o segundo a IUCN. Por ser uma esp?cie noturna, territorial e com h?bitos solit?rios, ainda h? muitos aspectos pouco estudados sobre seu comportamento em ambiente natural, entre eles a comunica??o ac?stica. Em seu repert?rio vocal, o lobo apresenta a vocaliza??o de longa-dist?ncia chamada de ?aulido? a qual, segundo a literatura, tem fun??o de manuten??o do espa?amento entre indiv?duos e/ou comunica??o entre os membros do par reprodutivo dentro do territ?rio. Nesse contexto, esse estudo teve como objetivos: 1) comparar quatro m?todos de detec??o dos aulidos de lobo-guar? em grava??es feitas em ambiente natural, buscando eleger o mais eficiente para nosso projeto; 2) entender como se d? o padr?o noturno de emiss?o dessas vocaliza??es, verificando se as condi??es clim?ticas e as fases da lua influenciam nas taxas de emiss?o de aulidos; e 3) testar o Monitoramento Ac?stico Passivo como ferramenta na identifica??o da presen?a de lobos-guar? em ambiente natural. A ?rea de estudo foi o Parque Nacional da Serra da Canastra (Minas Gerais, Brasil) e foram utilizados gravadores aut?nomos para aquisi??o dos sons, os quais gravaram durante toda a noite (18h-06h) durante cinco dias de dezembro/2013 e durante todos os dias dos meses de abril a julho/2014. Os m?todos de detec??o de aulidos foram testados e comparados com rela??o ao tempo necess?rio para analisar os arquivos, n?mero de falsos positivos e n?mero de aulidos corretamente identificados. O m?todo misto (XBAT+manual) foi o mais eficiente, encontrando 100% das vocaliza??es em quase metade do tempo do m?todo manual, e foi eleito para an?lise dos nossos dados. O estudo da varia??o temporal da emiss?o de aulidos verificou que os lobos vocalizam mais nas primeiras horas da noite, o que sugere uma fun??o social importante para esses chamados no in?cio de seu per?odo de atividade mais intenso. A velocidade m?dia do vento influenciou negativamente a frequ?ncia de vocaliza??es, o que pode indicar baixa recep??o sonora dos gravadores ou altera??o nos padr?es comportamentais dos lobos em condi??es de ventos fortes. ? necess?rio um melhor entendimento da varia??o sazonal da atividade vocal dos lobos-guar?, mas nosso estudo j? demonstra ser poss?vel detectar padr?es comportamentais de animais selvagens apenas atrav?s do som, validando o Monitoramento Ac?stico Passivo como ferramenta na conserva??o dessa esp?cie. / The maned wolf (Chrysocyon brachyurus Illiger 1815) is the biggest canid in South America and it is considered a ?near threatened? species by IUCN. Because of its nocturnal, territorial and solitary habits, there are still many understudied aspects of their behavior in natural environments, including acoustic communication. In its vocal repertoire, the wolf presents a longdistance call named ?roar-bark? which, according to literature, functions for spacing maintenance between individuals and/or communication between members of the reproductive pair inside the territory. In this context, this study aimed: 1) to compare four methods for detecting maned wolf?s roar-barks in recordings made in a natural environment, in order to elect the most efficient one for our project; 2) to understand the night emission pattern of these vocalizations, verifying possible weather and moon phases influences in roarbark?s emission rates; and 3) to test Passive Acoustic Monitoring as a tool to identify the presence of maned wolves in a natural environment. The study area was the Serra da Canastra National Park (Minas Gerais, Brazil), where autonomous recorders were used for sound acquisition, recording all night (from 06pm to 06am) during five days in December/2013 and every day from April to July/2014. Roar-barks? detection methods were tested and compared regarding time needed to analyze files, number of false positives and number of correctly identified calls. The mixed method (XBAT + manual) was the most efficient one, finding 100% of vocalizations in almost half of the time the manual method did, being chosen for our data analysis. By studying roarbarks? temporal variation we verified that the wolves vocalize more in the early hours of the evening, suggesting an important social function for those calls at the beginning of its period of most intense activity. Average wind speed negatively influenced vocalization rate, which may indicate lower sound reception of recorders or a change in behavioral patterns of wolves in high speed wind conditions. A better understanding of seasonal variation of maned wolves? vocal activity is required, but our study already shows that it is possible to detect behavioral patterns of wild animals only by sound, validating PAM as a tool in this species? conservation.

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