Species are not randomly distributed in space. One fundamental ecological theory predicts that each species has a confined set of environmental factors that determines the occurrence of a species in space. This is called the ecological niche of a species which can be broad or narrow, depending on the species. The question of which factors determine the ecological niche of a species, and hence its distribution, has attracted ecologists for a long time. One line of research has investigated whether a species’ niche differs between the edge and the core of its distribution. To survive at the edge, populations may have evolved regional ecotypes that are especially adapted to deal with suboptimal conditions. However, current species distribution models are insensitive to regional ecotypes and treat populations from the entire distribution area as equal. Consequently, erroneous estimation of ecological niches, and hence distribution areas of species, seems likely.
An exciting way of investigating this premise is to study neotropical bats (> 220 species) as they are species-rich and ecologically highly diverse (e.g. aerial insectivorous, gleaning animalivorous, frugivorous and nectarivorous species; different mobility levels). With species distribution models, I intend to compare niches of neotropical bats at the edges of their distribution ranges with niches at their core areas. The results will be contrasted with those from traditional approaches that consider the niches in the entire distribution area to be equal. This new approach is expected to be more adequate in its prediction of the bats’ distributions. It is also to be expected that differences in mobility, feeding behaviour and total range size will impact niche differentiation of bat species into regional ecotypes.
This study contributes to scientific discussions on the role of edge populations in evolutionary processes (speciation). The findings will also be vital to assessing the potential of species to adapt to shifting environmental conditions such as climate and land use change and for predicting species ranges of threatened species.
Furthermore species distribution modelling of the elusive aerial insectivorous species (bats that hunt for free-flying insects) had to be excluded from such analyses in the Neotropics in the past due to data paucity. This ecological group will be modelled in this study for the first time, which has been made possible because novel bioacoustic methods have recently increased the availability of occurrence data for this group. The species can be recognized thanks to their species-specific call types. The main focus of this study lays in Panama.