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Identification of regional ecotypes with species distribution models: niche differentiation of neotropical bats, with emphasis on the aerial insectivorous group

English title Identification of regional ecotypes with species distribution models: niche differentiation of neotropical bats, with emphasis on the aerial insectivorous group
Applicant Sattler Thomas
Number 139403
Funding scheme Fellowships for prospective researchers
Research institution
Smithsonian Tropical Research Institute
Université Joseph Fourier
Institution of higher education Institution abroad - IACH
Main discipline Ecology
Start/End 01.04.2012 - 31.03.2013
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All Disciplines (2)

Discipline
Ecology
Zoology

Keywords (5)

Spatial ecology; Species distribution modelling; Chiroptera; Speciation; Niche differentiation

Lay Summary (English)

Lead
Lay summary

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.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Collaboration

Group / person Country
Types of collaboration
Swiss Federal Research Institute WSL Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Smithsonian Tropical Research Institute Panama (South America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Institute of Experimental Ecology, University of Ulm Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events



Self-organised

Title Date Place
Introduction to the Bioacoustics of Bats 21.09.2012 Panama-City, Panama

Communication with the public

Communication Title Media Place Year
Media relations: print media, online media Scientificos de cinco paises aprenden sobre bioacoustica de murcialgos Panama News International 02.10.2012

Abstract

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 and contrast the results with those from traditional approaches that consider the niches in the entire distribution area to be equal (special focus on forest cover and quality, urbanisation, temperature, precipitation). It is to be expected that differences in mobility, feeding behaviour and total range size will impact niche differentiation of bat species into regional ecotypes. Therefore, the analysis will systematically select species to represent all classes within these three traits. In the past, species distribution modelling of the elusive aerial insectivorous species had to be excluded from such analyses in the Neotropics 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 study is split into two modules. Module 1 on the continental scale considers bats throughout their entire neotropical occurrence while module 2 focuses on bats on the landscape scale of Panama. On the long Isthmus of Panama (800 km) many North- and South American bat species reach their distribution boundary offering unique opportunities to study niche differentiation in edge and core populations. For Module 1 more than 290’000 occurrences from >220 species are available from the Global Biodiversity Information Facility. For module 2, the publicly available data set is enhanced with 64’000 Panamanian records stemming from several research projects. Finally, primary data from bioacoustic surveys in the canal region will be completed with new field surveys across the whole of Panama to include the vast ecosystem types and altitudinal ranges available. Recent advances in species distribution modelling overcome the limitations of single statistical methods by calculating species distributions with multiple techniques and by testing models with several approaches to quantify model robustness. 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. The collaboration with E. Kalko and her group at the Smithonian Tropical Research Institute in Panama and the University of Ulm offers a great opportunity, since I can profit from her unique knowledge of neotropical bats and her excellent contacts with essential cooperation partners. The visit to W. Thuiller at the University Joseph Fourier, Grenoble perfectly complements the Post-doc as he and his team are at the scientific front in species distribution modelling which permits reaching the ambitious goals of this project.
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