Banca de DEFESA: CAROLINA MARIA CARDOSO AIRES LISBOA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : CAROLINA MARIA CARDOSO AIRES LISBOA
DATA : 21/06/2017
HORA: 14:00
LOCAL: Sala de Reuniões da Pós-graduação
TÍTULO:

Sexual Selection and Visual modelling in Cnemidophorus ocellifer


PALAVRAS-CHAVES:

Female preference, Male-male interactions, UV Signaling, Male quality traits, Performance, Visual modeling


PÁGINAS: 57
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

Many lizards have acute visual systems with retinal photoreceptors that are sensitive to UV wavelengths, and display UV-reflecting color patches. In this study, we used UV full-spectrum reflectance spectrophotometry to collect data from Cnemidophorus ocellifer UV structural colouration. Using an arena-form experimental set, we obtained evidence for the role of UV signaling in sexual selection (mate choice and male-male interactions). Our results showed that UV chroma is important in female association preference, as females exhibit spatial preference for males of higher UV reflectance over males with experimentally reduced UV reflectance. We also found that, in staged encounters, C. ocellifer males with experimentally reduced UV reflectance were not more likely to lose contests than control males, but reflectance was negatively correlated with evaluation time. We also tested two male ornaments in C. ocellifer against morphological traits and physiological performance to assess whether colour signals are informative for male quality traits. We found that larger males had more intense short (UV) and medium wavelength chroma on dorsolateral eyespots and, in contrast, smaller-headed males had more intense UV chroma on outer ventral scales (OVS). We concluded that the same colour trait convey different messages depending on the body position of the signal, perhaps indicative of alternative signalling strategies. Moreover, higher brightness on OVS signals were associated with stronger bite force, being a reliable signal of fighting ability. These results suggest that there is a multiple signalling system in our model species. Finally, we modeled the visual system of C. ocellifer, snake and avian predators to access how colour patches appear to the receivers We found that there are colour dimorphism between sexes, with UV signals of males more conspicuous in reflectance and highly distinguishable from females to conspecifics visual system. UV signals were highly perceptible from body colouration and from natural background to conspecifics and less but still perceptible to predators, agreeing with sensory drive hypothesis. This thesis enlighten the role of sexual signals and their importance on intra and interspecific communications in lizards. Our findings support further studies on evolution and behavior and expand the knowledge on natural and sexual selections iniciated by Darwin.


MEMBROS DA BANCA:
Interno - 1678338 - ADRIAN ANTONIO GARDA
Externo à Instituição - DANIEL DE OLIVEIRA MESQUITA - UFPB
Externo ao Programa - 1476621 - DANIEL MARQUES DE ALMEIDA PESSOA
Presidente - 1715227 - GABRIEL CORREA COSTA
Externo à Instituição - MOACIR SANTOS TINÔCO - UCSal
Notícia cadastrada em: 19/06/2017 13:37
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