Bat species richness in live fences and in corridors of residual rain forest vegetation at Los Tuxtlas, Mexico

Fragmentation of lowland tropical rain forests has resulted in loss of animal and plant species and isolation of remaining populations that puts them at risk. At Los Tuxtlas, Mexico, lowland rain forests are particularly diverse in the bat fauna they contain and while most of the forests have been fragmented by human activity, many of the fragments still harbor diverse assemblages of bat species. To assess the effectiveness of corridors, among other options, to ameliorate the negative effects of fragmentation, we investigated bat species richness and relative abundance in one 6 km long section of live fences (LF) bordering a dirt road and in three 6 km long sections of residual forest vegetation along the sides of three permanent streams (BS, MS, HS). Netting of bats resulted in the capture of 967 bats. At the LF site we captured 12 bat species. 15 at the BS site, IS at the MS site and 23 at the HS site. Species richness was associated with average area of forest fragments within a 1000 m band on each side of each corridor (r = 0.97, p = 0.01). Only 28% of the species were common among sites. Frugivorous and insectivorous species accounted for 48% Each of bat captures while nectarivores accounted for 3%, sanguinivores for 0.5% and carnivore-frugivores for 0.5%. Edge habitat species such as Pteronotus parnelli and Sturnira lilium accounted for 50% of the captures. Frugivorous species such as Carollia brevicauda, Vampyrodes caraccioli, Dermanura phaeotis, D. toltecus and A. jamaicensis accounted for another 25% of bat captures. Recaptures of bats indicated bat movements from forest fragments to corridors and between corridors, with recapture distances ranging from 200 to 2000 m. Within corridor recaptures separated by several months from the original recapture date indicated individual bat revisitation to these sites. We discuss the value of there corridors to bats as stepping stones in the fragmented landscape.