Bat assemblage, interactions with flowers and vertical stratification in the Atlantic Forest, Southern Brazil

Author(s)

Hedda Carolina Schmidt Scultori

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2010-01-18

Examining board members

Marlies Sazima; Wesley Rodrigues Silva; Kayna Agostini

• Advisor: Marlies Sazima

Abstract

Bats form a diverse group. They are abundant and of great ecological importance, due to various interactions with other organisms in their environment. The interactions of bats with flowers may result in pollination. While these interactions may be relatively rare when compared with other types of pollinators, they are of great importance to the reproduction in various plant species where they occur. These plants and the rewards utilized by bats occur at differing levels of the forest, wherein environmental conditions vary with height, thus influencing the use of vertical space by these mammals. The present study looks to describe a community of bats in an area of Atlantic Rainforest in the state of Paraná, aspects of the interactions of anthophilous species and to investigate the occurrence of vertical stratification of these species of animals and plants. From May 2008 to April 2009, bats were captured in mist nets opened from the ground to the canopy (25 m), in gaps in an area of submontane forest, in order to verify the diversity of species, seasonality, time of activity and vertical stratification. In the first chapter, results on community structure of bats are presented. Six hundred seventy-nine bats were captured, belonging to three families and 20 species. In the functional classification, species belonging to seven guilds were observed. The diversity did not vary between wet and dry seasons. Bat activity occurred throughout night-hours, with the highest abundance and richness occurring between two and four hours after sunset, and the lowest abundance and richness occurring between the fifth and tenth hour after sunset. The general pattern found in the vertical stratification indicates that the majority of species utilize the full amplitude of forest heights with some species using principally the lower forest levels. The characteristics of the community were similar to other localities with similar topography, and data on the vertical stratification likely reflects the vegetative structure of the Atlantic Rainforest. In the second chapter, data on bat interactions with flowers are presented. Phenology of the species of plants visited by bats was studied. Nectar of these flowers was collected. Visiting behavior of the bats was observed, followed by capture with open mist nets placed in front of the flowers. Eight species of plants visited by bats were studied. These plants presented either an annual or sequential pattern of flowering. Among these species are trees, epiphytes and lianas, occurring between 0,5 m and 34 m. Whitish to greenish-white tubular and pincel flowers made up the majority of these species' flowers, which are visited by glossophagines acting as pollinators. Non-glossophagine bats were considered occasional pollinators to these species. Among the 20 species of bats captured by mist nets, three species were glossophagines, five were frugivorous and one was omnivorous, which may consume floral rewards. These rewards are available and are used by bats throughout the year at differing heights, although there was no correlation among heights of occurrence and registered flights. While the results of this study are similar to other bat studies in the Atlantic Rainforest, they serve to highlight new perspectives on the study of bat communities and floral interactions (AU)