Factors in the Geographical Dispersal of Chameleons

For centuries, naturalists have wondered how chameleons spread across Africa, nearby islands, and even into Asia and Europe. A recent phylogenetic study of 181 species across nine regions — from North Africa and Arabia to Madagascar, Comoros, and India — highlights three decisive traits: coastal proximity, body size, and extreme life cycles.

Species living within 10 km of the sea dispersed far more widely than inland forms, echoing patterns seen in skinks and crocodiles. Larger chameleons also proved more mobile, aided by lower metabolic demands and larger clutches. Life history added another twist: species with either very rapid or very slow reproductive cycles spread farther than those with moderate rhythms. Fast breeders such as Furcifer polleni, Furcifer cephalolepis (Comoros), and Chamaeleo zeylanicus (India) exemplify successful overseas colonizers, while slow breeders thrived in continental expansion.

The most dispersive group — 34 coastal, large-bodied species with extreme life cycles — showed a 98% higher spread rate than others. Though theoretical, the findings reveal how ecological traits shaped the historical biogeography of chameleons.

Reference:

Weil, S.-S., Gallien, L., Lavergne, S., Börger, L., Hassler, G. W., Nicolaï, M. P. J., & Allen, W. L. (2024). Chameleon biogeographic dispersal is associated with extreme life history strategies. Ecography. https://doi.org/10.1111/ecog.06323