The habitat first rule (HFR) proposes that radiating species initially diversify into habitat specialists and later into dietary specialists within a given habitat, whereas the general vertebrate model (GVM) adds divergence of sexually selected traits as a possible third axis of specialization subsequent to habitat and dietary divergence. In this study, using 12 Miniopterus spp. from Madagascar we test predictions of the HFR and GVM from ecological and evolutionary perspectives on Grinnellian and Eltonian niche structures.
We used environmental niche models (ENMs) to quantify the Grinnellian niche, both for current and last inter-glacial climates. We used null models to examine Eltonian niche patterns of sympatric species in terms of their phylogenetic relatedness and phenotypic and sensory characters associated with the trophic niche-body size, skull morphology and echolocation.