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Previous issue date: 2012-02-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Intending to explain the extraordinary lizard coexistence levels found in Australian deserts, Morton & James (1988) figured out a hypothesis which defends that the termite diversity would bring about lizard radiation. This study aims to verify the validation of that hypothesis in Caatinga lizard assemblages. This study also objectives verifying if the termite defense mechanisms influence their consuming levels by lizards and if this pattern differs between different lizard lineages. Termites were collected using a standardized sampling protocol of termites. Besides using haphazard sampling, we collect lizards with 108 pitfall traps in each area. Intending to check the linkage between the termite and lizard assemblages, the lizard stomach contents were analyzed and then a canonical correspondence analysis was performed. The presence of nonrandom patterns of diet overlap among the lizard species was also examined. Aiming to check if the defense mechanisms of termite influence their consuming pattern by lizards it was performed a laboratory experiment where termite with different defense mechanisms were offered to lizards of two different lineages. We verified that lizard assemblages do not consume termites according to termite abundance in ecosystems. Furthermore, mean niche overlap lizard species did not differ significantly from that expected by chance. We found that termite chemical defense mechanism does influence the termite s pattern consuming by lizards. These results do not corroborate premises which support Morton & James hypothesis (1988) and point out that lizard do not chose termites based on their abundance, but, trying to avoid consuming termites which exhibit chemical defense mechanisms. This defense mechanism, however, may not be the only explanation to patterns of termite s consuming by lizards. / Ao tentar explicar a extraordin?ria taxa de coexist?ncia de lagartos em desertos Australianos, Morton & James (1988) formularam uma hip?tese em que a diversidade de t?rmitas promoveria uma diversifica??o dos lagartos. O presente estudo visa verificar se essa hip?tese ? v?lida para as taxocenoses de lagartos da Caatinga. Objetiva-se tamb?m verificar se os mecanismos de defesa dos t?rmitas influenciam a taxa com que esses s?o consumidos pelos lagartos e se esse padr?o difere entre diferentes linhagens de lagartos. Para a coleta dos t?rmitas foi aplicado um protocolo padronizado de amostragem term?tica. Para a coleta dos lagartos, al?m da busca ativa, foram instaladas 108 armadilhas de queda em cada ?rea. Para verificar a rela??o entre as taxocenoses de lagartos e t?rmitas foi analisado o conte?do estomacal dos lagartos e, em seguida, foi realizada uma An?lise de Correspond?ncia Can?nica. Posteriormente realizou-se uma an?lise de sobreposi??o de nicho. Para verificar se o mecanismo de defesa dos t?rmitas influencia o seu padr?o de consumo pelos lagartos, realizou-se um experimento onde se ofertou t?rmitas com diferentes mecanismos de defesa para lagartos de duas linhagens diferentes. Verificou-se que a taxocenose de lagartos n?o consome os t?rmitas de acordo com a abund?ncia destes no ecossistema. Al?m disso, a sobreposi??o de nicho alimentar n?o foi menor do que o esperado ao acaso. Verificou-se que o mecanismo de defesa qu?mica influencia sim o padr?o de consumo dos t?rmitas pelos lagartos. Esses resultados n?o corroboram as premissas que alicer?am a hip?tese de Morton & James (1988) e indicam que os lagartos n?o selecionam os t?rmitas a serem consumidos devido ? sua abund?ncia, mas, sim, de modo a evitar t?rmitas que exibissem mecanismos de defesa qu?mica. A presen?a desse mecanismo de defesa, por?m, parece n?o ser a ?nica explica??o para o padr?o de consumo dos t?rmitas pelos lagartos.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/14024 |
| Date | 23 February 2012 |
| Creators | Souza, Heitor Bruno de Araujo |
| Contributors | CPF:96425601434, http://lattes.cnpq.br/8396727262741273, Costa, Gabriel Corr?a, CPF:90773306153, http://lattes.cnpq.br/2151112850152895, Vieira, Washington Luiz da Silva, CPF:02186680408, http://lattes.cnpq.br/0539509813323032, Vasconcellos, Alexandre |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ecologia, UFRN, BR, Bioecologia Aqu?tica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | Portuguese |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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