Modelling climate envelopes for rare Madagascan Butterflies
	>Introduction
	Existing bioclimatic models
	Methods
	Data sets
	Results
	Approach to climatic modelling
	Testing the Models
	Atlas applications
	Discussion
	References
	Predictive atlas of rare Madagascan butterflies
	Correspondence
	Modelling climate change effects on African Plant species

This work is funded by:

Introduction

Cite as: Lees, D.C. 2002. Modelling climate envelopes for rare Madagascan butterflies. Final report with atlas. Unpublished report to Conservation International, Washington.Biogeography and Conservation Laboratory,Dept. of Entomology,Cromwell Rd.,S. Kensington,SW7 5BD

Despite mounting knowledge of the importance of Madagascar's highly endemic biota, there are as yet no published examples of bioclimatic modelling for suites of species on the island, and so no assessments have been possible of the potential impact of climate change. Now that high resolution datasets are emerging, whilst habitat loss continues apace in an uncertain political climate (e.g. Bradt, 2002), time is ripe for such studies. Evaluating how organisms may respond to the environments and landscapes of the near future is vital to inform conservation and restoration planning, and ultimately to avert an extinction catastrophe on the island. Bioclimatic and habitat models can be applied to future climate and forest fragmentation scenarios, as soon as they become available.

Butterflies are a particularly appropriate group of organisms to examine, because they are highly sensitive to climate change (work done in temperate regions: Parmesan, 1996; Hill et al., 1999). Moreover, it is likely that butterflies are somewhat more representative of overall biodiversity (as most species are insects) than, let us say, birds or mammals and are likely to show more fine-grained responses to the environment (Kremen, 1992). As a group that shows a wide range of dispersal abilities, but with the majority of species forest-restricted, Madagascan butterflies constitute an excellent group to examine the potential to track future climate space in the context of habitat fragmentation models. On Madagascar, butterflies exhibit a 74% level of species endemism when both described and undescribed species are considered (Lees et al. in press), increasing to 100% in some large evolutionary radiations on the island (Raharitsimba, 1997). Also, their alpha-taxonomy has been subject to recent (Lees, 1997) and ongoing (Lees et al. in press) revision. Not least, a high quality point dataset for Madagascar butterflies has recently been compiled that builds on previous distributional models for all ca. 300 described species on the island (Lees et al., 1999).

Objectives

· To validate available climatic surface models for the Madagascar biodiversity hotspot

· To evaluate techniques for producing species bioclimatic models

· To model present day climate envelopes using the selected technique for a set of Madagascar butterflies of potential conservation concern

· To explore how such models might be applied to future climate change in the context of anthropogenic habitat fragmentation

These four objectives are refinements of the work that was proposed in Phase I of the proposal of Lovett and McClean (2001). Although originally proposed to model a few species, it has proved possible here to model 48 species (1/6 of the described butterfly fauna, including many of the rarest species). This report is self-contained, embedding a representative sample of the climate surfaces and a complete atlas of all the species model surfaces produced for this pilot study.

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