Ecology and habitat demand of species determine their population structure and dynamics as well as their behaviour and responses to habitat changes. Species specialised to forest ecosystems are assumed to behave differently in these ecosystems than generalist species, which also occur in open ecosystems. For assessing how species with different ecological performance thrive in a small remnant forest, we selected two butterfly species with different degrees of habitat specialisation. We conducted a mark-release-recapture study in a church forest in northern Ethiopia to investigate the population ecology of these two species. As model species we selected the forest species Junonia terea and the habitat generalist Phalantha phalantha. We found for both species that one generation was fading out in the second half of the dry season but was substituted by the onset of eclosion of a follow-up generation. This population dynamic was also supported by population size dynamics, capture probability and survival probability. Life spans were comparatively short for both species, except for some few individuals. Dispersal behaviour of P. phalantha was very low, while J. terea was more dispersive, a common feature in forest butterflies. P. phalantha preferred habitats characterised by ground cover, litter, flowering plants and little shade. It thus preferred light spots inside the forest confirming the typical ecological niche of a generalist species being more common in open habitats than in forests. No habitat preferences were obtained for the euryoecious forest species J. terea, which thus occurs virtually anywhere in wooded habitats. Our study clearly shows that the ecological performance of these two species had a significant influence on habitat selection, population dynamics, and behaviour. Our findings underline the high conservation value of still intact forest ecosystems to hold typical and highly specialized forest species.
原文链接
分享
引用
