Os morcegos frugívoros Carollia perspicillata e Sturnira lilium apresentam distribuição de atividade similar durante a noite? Uma análise local e regional

Abstract

The moon light and the differences in bat’s habitat composition are some of the main factors that may influence on activity pattern of fruit bats. Studies on bats distribution of activity are important for elucidating how and when these animals forage and some of the mechanisms that allow the coexistence of similar species. Therefore the present study aimed to examine, in local and regional scale, the distribution of activity of Carollia perspicillata and Sturnira lilium in the state of Rio de Janeiro. Five localities with more than 40 captures of these species were selected: Reserva Biológica de Araras, Parque Natural Municipal Penhasco Dois Irmãos, Santuário da Vida Silvestre Serra da Concórdia, Ilha da Marambaia and Ilha da Gipóia. The hours of captures were transformed in minutes after sunset. A total of 707 captures from C. perspicillata and 927 from S. lilium were analyzed. No evidence of influence of brightness of the moon in the capture of C. perspicillata were found in any locality. For S. lilium, in two locations brightness influenced his capture, possibly due to the characteristics of the vegetation in, resulting in a greater risk of predation in the locality. The two species activity remained generally constant throughout the night, peaking between the first three hours of the night, which may be due to greater availability of resources during this period. The distribution of the activity of both species during the night was different, suggesting a variation in temporal niche that facilitate the coexistence of species in different localities. It was concluded that the activity of both species is greatest in the early evening, additional activity peaks may occur after the middle of the night. The spatial heterogeneity observed in each locality studied, the difference in food availability, in addition to temporal variation in the niche, were some of the factors that facilitated the coexistence of these species at these sites.