Herpetological diversity across intact and modified habitats of Nosy Komba Island, Madagascar

ABSTRACT

A six month herpetological survey was undertaken between March and September 2015 on Nosy Komba, an island off of the north-west coast of mainland Madagascar which has undergone considerable anthropogenic modification. A total of 14 species were found that have not been previously recorded on Nosy Komba, bringing the total island diversity to 52 (41 reptiles and 11 frogs). The species assemblage, richness and abundance of four distinct habitat types were compared: closed-canopy forest, disturbed-canopy forest, shade-grown coffee plantation and mixed open plantation. The anthropogenic habitats on Nosy Komba were found to be of high conservation value for reptile species, where species richness and abundance found during surveys was equal to or higher than closed-canopy forest. By contrast, the abundance and species richness for frogs was reduced in anthropogenic habitats, especially in sun-exposed plantations. The forested areas of Nosy Komba contain twelve IUCN threatened species (9 reptiles and 3 frogs). Of these, Uroplatus henkeli, Uroplatus ebenaui, Phelsuma seippi, Zonosaurus subuniclor, Stumpffia psologlossa and Stumpffia pygmaea were also found in shade-grown coffee plantations, demonstrating the conservation value of these anthropogenic environments. Five threatened species on Nosy Komba were found exclusively in forested areas: Brookesia minima, Brookesia ebenaui, Lygodactylus madagascariensis, Rhombophryne testudo and Thamnosophis stumpffi. Our surveys demonstrate the importance of Nosy Komba for conserving regionally endemic and threatened species, and the often under-appreciated value of anthropogenic environments in species conservation, when also coupled with the protection of primary forest.

KEYWORDS:

• Herpetofauna
• conservation
• Madagascar
• Nosy Komba
• Sambirano

Acknowledgements

Thank you to Madagascar Research and Conservation Institute (MRCI) for their support, facilities and funding that made the research possible; to our local guides Jimmy Norcien Tongazara and Roby Duchen; to long-term volunteers Aren Armari, Elitsa Penkova, Tess Mulligan, Rosie McTigue and Adam Richards; to forest interns Michael Burrow and Brandon Baxter; to Guillaume Demare for photographing the A. mandokava; to Chloe Amoo who got the project started; to loyal friends Phoebe West and Vicky Abbott, and to all other volunteers who supported MRCI and assisted in the data collection.

Geolocation information

The study took place on the northern half of Nosy Komba island, centered around point:

-13.450034°, 48.336895°

Disclosure statement

No potential conflict of interest was reported by the authors.