Banca de DEFESA: BRUNO DE SOUZA MAGGI

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : BRUNO DE SOUZA MAGGI
DATA : 30/08/2017
HORA: 14:00
LOCAL: Sala de reuniões – Prédio de Ecologia
TÍTULO:

Collor and sexual selection in Tropidurus hispidus

PALAVRAS-CHAVES:

female mate choice, male competition, coloration, lizards, South America

PÁGINAS: 50
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

Within this proposal, we aim to resolve the following issues: Are there differences in coloration between males and females of Tropidurus hispidus? Do females use color traits to choose between mates? Does male coloration predicts the outcome of agonistic encounters? For that, we will use as model system T. hispidus Spix (1825), the larger species of the Torquatus group. Lizards of this genus are diurnal, extremely abundant, heliophiles, sit-and-wait foragers, and territorials, occurring predominantly in open areas. We used a spectrophotometer to measure color variables and visual modeling using the visual sensitivity data of Podarcis mularis. This data was used to answer the first question. To answer questions 2 and 3 we performed two controlled experiments with size-paired males. The first, a female mate-choice experiment in which we put males in a terraria enclosure with three separated parts. We assigned each male to a compartment in which they did not have mutual visual contact. We assigned females to the third compartment that enables visual contact to both the males. The second, a agonistic interaction experiment among males, in which we put a pair of males in a single terraria enclosure for 30 min. During the experiment period we recorded behavioral displays in order to determine winners of each trial. Separately, we used color variables to differentiate males from females. Our first results clearly showed that T. hispidus exhibits sexual dichromatism and that it is perceived as conspecific. Of the eleven areas of the body used to compare males and females, nine showed significant differences. For the dorsal region and head, the red chroma is the variable that most discriminates males from females. While for the ventral region of the thigh, cloaca, flank, belly and throat the glow is the one that best distinguishes males from females. For the base of the tail the tint better discriminates. The UV chroma in the ventral region of the tail base also distinguishes the sexes. The visual modeling showed that these differences are perceived by another lizard, confirming spectrophotometry data. In the experiment of choice by the females the region and the variable that discriminated best chosen and not chosen were respectively thigh ventral and chroma 8. For the competition experiment between the males the belly and collar regions, as well as the blue, 3 And 8 chroma variables, better discriminated winners and losers. With this, we intend to have contributed to a better understanding of the evolution of the signal design and how the intra- and intersexual selections act in this process in T. hispidus.

MEMBROS DA BANCA:
Interno - 1678338 - ADRIAN ANTONIO GARDA
Externo ao Programa - 1476621 - DANIEL MARQUES DE ALMEIDA PESSOA
Externo à Instituição - DANIEL OLIVEIRA MESQUITA - UFPB
Presidente - 1715227 - GABRIEL CORREA COSTA
Externo à Instituição - MIGUEL FERNANDES KOLODIUK - IFRN