Sistemas de acasalamento com defesa territorial : evolução, regras das disputas e seleção de territorios em satirineos neotropicais / Mating systems with territorial defense : evolution, contest rules and territory selection in neotropical satyrine Butterflies

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Territorial conflicts in flying insects may be resolved through many different ways. In male butterflies, size, age and motivation are often reported as important determinants of the winning chances. However, the rules used when fighting, the biological context that affects the intensity of agonistic behaviors, and the functional role of male traits in the contests costs generation are poorly known. In this study I investigated a series of characteristics that may influence the costs and benefits of territorial conflicts using the satyrine species Hermeuptychia hermes (Fabricius, 1775), Moneuptychia soter (Buttler, 1877), and Paryphthimoides phronius (Buttler, 1867) as study organisms. In chapter 1, I used high-speed video imagery to investigate whether intraspecific disputes between male H. hermes and male M. soter occur with physical contact. Additionally, I removed resident males from their defended sites and the subsequent intruders that established on those areas after the resident removal to assess if wing wear, body mass, fat content and flight muscle ratio are important determinants of male residency status. Resident males of H. hermes were similar in body weight and thoracic muscle mass to their intruder rivals, but had fewer wing wear and higher fat content. Resident males of M. soter, on the other hand, were heavier than intruder males. Male H. hermes divided their interaction in up to three phases consisting of circular flights, ascending spirals and back and forth persecutions, whereas male M. soter used much slower circular flights that were often followed by linear persecutions and clicking sound emissions. Physical contacts were not observed for both species. In chapter 2, I investigated the role of previous residence on contest resolution in the butterfly H. hermes. By inducing territorial interactions between males that behaved as residents (one original resident and another resident-induced one) and comparing them with natural contests between resident and intruder males, it was possible to show that previous residence increases the chances of victory. Body mass positively affected the winning chances in the induced fights, but was unimportant among the natural ones. Finally in chapter 3, I investigated the role of feeding resources in the territory establishment by males of the butterfly P. phronius. Male of this species typically defend sunny clearings on the forest edge which do not contain any evident resource. However, previously undefended sunny clearings were occupied by territorial males after receiving soft fermenting fruit. Although males which established on sites containing feeding resources seem to forage on the fermenting fruit, territory selection experiments shows that males prefer to defend sites without resources. This type of variation in the mate locating tactics has never been previously investigated for butterflies. In addition of helping the understanding of the evolutionary processes leading to different mate-locating strategies, this system allows the testing of the influence of different reproductive behaviors on the intensity of territorial conflicts between males

ASSUNTO(S)

territorialidade (zoologia) sexual selection in animals animais - comportamento animal behavior territoriality (zoology) seleção sexual em animais

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