Genetic structure, dispersal ability and chemical signalling in sleeping aggregations of males of Euglossa melanotricha

• Grant number: 15/07342-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2016
• End date: April 30, 2018
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Marco Antonio Del Lama
• Grantee: Aline Candida Ribeiro Andrade e Silva
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Many animal species form communal nocturnal roosts. A number of potential benefits have been suggested for this behavior, including protection against predators, thermoregulation, the aggregation of conspecific males facilitating the attraction of females, and the synchronous rearing or development of offspring. However, such aggregations may also entail costs, such as an increase in competition and the transmission of diseases, in addition to the vulnerability to predation of the individuals in the periphery of the roost. The balance between these costs and benefits may be influenced by kinship. If an aggregation is made up of related individuals, the ecological benefits may be reinforced by inclusive fitness. On the other hand, if the purpose of the aggregation is to attract reproductive partners, reduced relatedness would minimize the risks of inbreeding. If kinship is an important factor for the maintenance of the aggregations, site fidelity may be determined by proximal mechanisms such as chemical signals. The site fidelity of male Euglossa melanotricha to specific nocturnal roosts was inferred from the year-long monitoring of aggregations of this species in the leaves of Serpocaulon triseriale (Pteridophyta: Polypodiaceae). However, the mechanisms determining the formation of these aggregations are still unclear, and may be related to (1) the number of families of brothers found in these aggregations, (2) the genetic relatedness among the males in different roosts, (3) the structure of the aggregations, (4) the potential for the dispersal of the males from their home nests to the roosts, and (5) the role of chemical signals in conspecific site fidelity. The present study will integrate behavioral observations, genetic analyses of relatedness using microsatellite markers, and the sampling and analysis of cuticular chemicals in the males using non-lethal techniques. Five roosts of male Euglossa melanotricha located in the municipality of Campo Formoso, Bahia, will be monitored in the present study. The aggregations have occurred in the same area for more than 10 years. To determine the origin of the males found in the aggregations and to sample individuals recently emerged from their home nests, male specimens will be collected using scent baits set in local forest fragments. The results of this study will provide valuable insights into the biology of male euglossines, as well as a better understanding of the mechanisms that determine the formation of the roosts.