Full text
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| Author(s): |
Victor Toni Lourenço
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2015-07-15 |
| Examining board members: |
Woodruff Whitman Benson;
André Victor Lucci Freitas;
Paulo Enrique Cardoso Peixoto
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| Advisor: | Woodruff Whitman Benson |
| Abstract | |
Although butterflies of the Neotropical genus Hamadryas have been known for over two hundred years, even today they continue to intrigue researchers by their remarkable ability to produce loud cracking sound. These butterflies typically inhabit clearings and forest edges, where they can be observed engaging in aggressive pursuits. Darwin suggested that these chases were directly related to courtship, but today there is speculation that males of several Hamadryas species defend mating sites, although conclusive evidence is lacking. In this study, developed in a semi-deciduous forest in southeastern Brazil, we evaluate and characterize the territorial behavior of Hamadryas amphinome (Linnaeus, 1767), also known as Red Cracker butterfly. We used the focal individual method to compile daily activity records for resident territorial males describing behavior, daily activity pattern, contest success and site tenacity of free-ranging marked butterflies. We also tried to understand the factors influencing the outcome of territorial contests, such as prior residence, age and the determinants of fighting ability, such as wing length and body mass. We found that males of H. amphinome defend territory sites from perches on canopy limbs of emergent trees in clearings and along forest edges. In this species, territories seem to function exclusively as `landmark encounter sites¿, since they lack food sources and host plants attractive to females. We observed nine copulations around the perching sites, mostly between young females and resident territorial males. Courtships and matings overlapped the peak period of territorial defense. Male residents expel intruders in aerial contests characterized by horizontal chases and circular flights, accompanied by vigorous clicking. The fact that males perch on sunny limbs and the timing of defense in the first hours of the afternoon seem to reflect the need of these butterflies in maintaining an elevated body temperature during aerial contests. Resident males typically defend the same perching sites on subsequent days and tenure time among individuals is highly variable. On average, residents, primary owners and contest winners had a greater wing length than intruders, secondary owners and contest losers. Winning ratio of male residents also correlated positively with wing length. Contest duration showed a positive correlation with wing wear and mass of loser residents. Despite the apparent relevance of size for the settlement of territorial disputes in H. amphinome, it remains to be seen how this attribute is related to the accumulation of costs during agonistic interactions (AU) | |
| FAPESP's process: | 09/13507-0 - Defense of Mating Territories in Hamadryas sp. (Lepidoptera: Nymphalidae). |
| Grantee: | Victor Toni Lourenço |
| Support Opportunities: | Scholarships in Brazil - Master |