Abundance, body size and movement patterns of a tropical treefrog in continuous and fragmented forests in the Brazilian Amazon     

Selvino Neckel-Oliveira  Claude Gascon 《Biological conservation》2006,128(3):308-315

Phyllomedusa tarsius is a hylid frog that breeds in ponds located in a range of habitats from continuous forests to severely disturbed matrix habitats in Central Amazon. During three reproductive seasons, we followed the movement patterns, measured body size and registered abundance and residency time of this species in five habitats: pasture, Vismia regrowth, Cecropia regrowth, 1 and 10 ha forest fragments, and continuous forest. The frog captures were strongly correlated with rainfall in all disturbed habitats, but not in continuous forest, probably because individuals respond more directly to rainfall patterns in more open habitats. Males in disturbed habitats were smaller than those found in continuous forest, perhaps as a result of differences in habitat quality. Males remained at sites for longer periods in fragments and continuous forest compared to matrix habitats. Here again, the quality and suitability of breeding sites in matrix habitats may be lower than in continuous forest resulting in the need for more movement. We found bigger subpopulations in matrix habitat ponds and a higher percentage of individuals moving among them when compared to continuous forest ponds. Constant movement of individuals among disturbed subpopulations decreases population isolation and increases interbreeding among different subpopulations. No movement between individuals from continuous forest ponds and disturbed habitats was observed. This suggests that the disturbed habitat subpopulations are not acting as sink subpopulations for continuous forest populations. The maintenance of individuals in fragments is more dependent on local conditions for reproduction and on subpopulations in the matrix habitat than on recruitment of individuals from populations in continuous forest.  相似文献   

Effects of landscape change on clutches of Phyllomedusa tarsius, a neotropical treefrog     

Selvino Neckel-Oliveira 《Biological conservation》2004,118(1):109-116

Phyllomedusa tarsius is an arboreal frog species that suspends its eggs on leaves above water in order to achieve the high relative humidity necessary for embryo development. I compared the hatching success of P. tarsius in ponds located in pasture, Vismia spp. regrowth, Cecropia spp. regrowth, forest fragments and continuous forest at a site in central Amazônia. Reproductive success of P. tarsius is measured as percentage of clutches producing at least one tadpole and number of tadpoles produced per clutch. Reproductive success was higher in Cecropia regrowth, forest fragments and continuous forest, compared to pasture and Vismia regrowth. Desiccation and flooding were the main causes of clutch loss in pasture and Vismia regrowth, while predation was more frequent in forest and Cecropia regrowth. The levels of successful of P. tarsius clutches observed across all habitat types suggests that a landscape mosaic including pasture, secondary growth and forest fragments may allow for recolonization and genetic exchange to occur in isolated forest patches.  相似文献