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Previous issue date: 2013-03-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This study investigated the influence of intrinsic and extrinsic factors on the feeding ecology
and foraging behavior of the whiptail lizard Ameivula aff. ocellifera, a new species widely
distributed in the Brazilian Caatinga, and that is in process of description. In attendance to the
objectives, the Dissertation was structured in two chapters, which correspond to scientific
articles, one already published and the other to be submitted for publication. In Chapter 1
were analyzed the general diet composition, the relationship between lizard size and prey size,
and the occurrence of sexual and ontogenetic differences in the diet. Chapter 2 contemplates a
seasonal analysis of diet composition during two rainy seasons interspersed with a dry season,
and the quantitative analysis of foraging behavior during two distinct periods. The diet
composition was determined through stomach analysis of lizards (N = 111) collected monthly
by active search, between September 2008 and August 2010, in the Esta??o Ecol?gica do
Serid? (ESEC Serid?), state of Rio Grande do Norte. Foraging behavior was investigated
during a rainy and a dry month of 2012 also in ESEC Serid?, by determining percent of time
moving (PTM), number of movements per minute (MPM) and prey capture rate by the lizards
(N = 28) during foraging. The main prey category in the diet of Ameivula aff. ocellifera was
Insect larvae, followed by Orthoptera, Coleoptera and Araneae. Termites (Isoptera) were
important only in numeric terms, having negligible volumetric contribution (<2%) and low
frequency of occurrence, an uncommon feature among whiptail lizards. Males and females
did not differ neither in diet composition nor in foraging behavior. Adults and juveniles
ingested similar prey types, but differed in prey size. Maximum and minimum prey sizes were
positively correlated with lizard body size, suggesting that in this population individuals
experience an ontogenetic change in diet, eating larger prey items while growing, and at the
same time excluding smaller ones. The diet showed significant seasonal differences; during
the two rainy seasons (2009 and 2010), the predominant prey in diet were Insect larvae,
Coleoptera and Orthoptera, while in the dry season the predominant prey were Insect larvae,
Hemiptera, Araneae and Orthoptera. The degree of mobility of consumed prey during the
rainy seasons was lower, mainly due to a greater consumption of larvae (highly sedentary
prey) during these periods. Population niche breadth was higher in the dry season, confirming
the theoretical prediction that when food is scarce, the diets tend to be more generalized.
Considering the entire sample, Ameivula aff. ocellifera showed 61,0 ? 15,0% PTM, 2,03 ?
0,30 MPM, and captured 0,13 ? 0,14 per minute. Foraging mode was similar to that found for
other whiptail lizards regarding PTM, but MPM was relatively superior. Seasonal differences were verified for PTM, which was significantly higher in the rainy season (66,4 ? 12,1) than
in the dry season (51,5 ? 15,6). It is possible that this difference represents a behavioral
adjustment in response to seasonal variation in the abundance and types of prey available in
the environment in each season / Este estudo investigou a influ?ncia de fatores intr?nsecos e extr?nsecos sobre a ecologia
alimentar e o comportamento de forrageamento do lagarto cauda-de-chicote (whiptail)
Ameivula aff. ocellifera, uma esp?cie nova com ampla distribui??o na Caatinga, e que est? em
fase de descri??o. Em atendimento aos objetivos, a Disserta??o foi estruturada na forma de
dois cap?tulos, os quais correspondem a artigos cient?ficos, um j? publicado e o outro a ser
submetido ? publica??o. No Cap?tulo 1 s?o analisadas a composi??o geral da dieta, a rela??o
entre o tamanho corporal dos lagartos e o tamanho das presas consumidas, e a ocorr?ncia de
diferen?as sexuais e ontogen?ticas na dieta. O Cap?tulo 2 contempla a composi??o da dieta em
termos sazonais, durante duas esta??es chuvosas intercaladas por uma esta??o seca, e an?lise
quantitativa do comportamento de forrageamento durante dois per?odos distintos. A
composi??o da dieta foi identificada atrav?s da an?lise do conte?do estomacal de lagartos (N
= 111) coletados mensalmente por busca ativa entre setembro de 2008 e agosto de 2010, na
Esta??o Ecol?gica do Serid? (ESEC Serid?), estado do Rio Grande do Norte. O
comportamento de forrageamento foi investigado durante um m?s chuvoso e um m?s seco do
ano de 2012 tamb?m na ESEC Serid?, avaliando-se a porcentagem do tempo gasta em
movimento (PTM), o n?mero de movimentos por minuto (MPM) e taxa de captura de presas
pelos lagartos (N = 28) durante o forrageamento. A principal categoria de presa na dieta de
Ameivula aff. ocellifera foi Larvas de insetos, seguido por Orthoptera, Coleoptera e Araneae.
T?rmitas (Isoptera) foram importantes somente em n?mero, com contribui??o volum?trica
desprez?vel (<2%) e baixa frequ?ncia de ocorr?ncia, um tra?o incomum entre os lagartos
whiptails. Machos e f?meas n?o diferiram nem na composi??o da dieta nem no
comportamento de forrageamento. Adultos e juvenis se alimentaram de categorias de presa
similares, mas diferiram no tamanho das presas. Os tamanhos m?ximo e m?nimo das presas
foram positivamente correlacionados com o tamanho dos lagartos, sugerindo que na
popula??o estudada os indiv?duos sofrem uma mudan?a ontogen?tica na dieta, consumindo
itens alimentares maiores ? medida que crescem, e ao mesmo tempo excluindo presas
menores. A dieta apresentou diferen?as sazonais significativas; durante as duas esta??es
chuvosas (2009 e 2010), as presas predominantes na dieta foram Larvas de inseto, Coleoptera
e Orthoptera, enquanto na esta??o seca as presas predominantes foram Larvas de inseto,
Hemiptera, Araneae e Orthoptera. O grau de mobilidade das presas consumidas durante as
esta??es chuvosas foi menor, principalmente devido ao maior consumo de larvas (presas
altamente sedent?rias) durante esses per?odos. A largura de nicho da popula??o foi maior na
x
esta??o seca, confirmando a predi??o te?rica de que quando o alimento ? escasso, as dietas
tendem a ser mais generalizadas. Considerando a amostra total, Ameivula aff. ocellifera
apresentou 61,0 ? 15,0% PTM, 2,03 ? 0,30 MPM, e capturou 0,13 ? 0,14 presas por minuto.
O modo de forrageamento foi similar ao encontrado para outros lagartos whiptails quanto a
PTM, mas MPM foi relativamente superior. Diferen?as sazonais foram verificadas quanto a
PTM, que foi significativamente maior na esta??o chuvosa (66,4 ? 12,1) que na esta??o seca
(51,5 ? 15,6). ? poss?vel que essa diferen?a represente um ajuste comportamental em resposta
? varia??o sazonal na abund?ncia e tipos de presas dispon?veis no ambiente nas diferentes
esta??es
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17344 |
| Date | 27 March 2013 |
| Creators | Sales, Raul Fernandes Dantas de |
| Contributors | CPF:10843175400, http://lattes.cnpq.br/6388455734228621, Bellini, Bruno Cavalcante, CPF:00990546470, http://lattes.cnpq.br/8609476121598138, Dias, Eduardo Jos? dos Reis, CPF:88622789500, http://lattes.cnpq.br/8426855028199294, Freire, Eliza Maria Xavier |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Psicobiologia, UFRN, BR, Estudos de Comportamento; Psicologia Fisiol?gica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| 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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