(Re-)discovery of threatened vertebrates in western Madagascar by eDNA metabarcoding

Metabarcoding of insect bulk samples to recover eDNA of endemic vertebrates in the wild

The Menabe Central region is home to the largest remaining area of deciduous dry forests in western Madagascar. Protected since 2015 by the Aire Protégée Menabe Antimena (APMA), the area is characterized by high species diversity and surpasses other forest regions in terms of local endemism and anthropogenic pressure. The continuous loss and degradation of forest habitat is leading to a steady decline in the distribution ranges of local endemics and regional population declines of many species found there. For very rare or hard-to-find species, it is sometimes difficult to confirm their continued existence using conventional methods.  The aim of this project is to test an innovative eDNA approach to (re)discovering vertebrate species in a natural forest. In 2022, we began collecting mass insect samples to test the potential of metabarcoding for amplifying vertebrate eDNA.

Our target species are the eight lemur species and other endemic vertebrate species. Six nocturnal lemur species are found in the forests of Menabe Central: the smallest known primate, Madame Berthe's mouse lemur (Microcebus berthae), is found exclusively in this region and coexists with the gray mouse lemur (Microcebus murinus), the fat-tailed dwarf lemur (Cheirogaleus medius), the giant mouse lemur (Mirza coquereli), the fork-marked lemur (Phaner pallescens), and the red-tailed sportive lemur (Lepilemur ruficaudatus). In addition, the larger diurnal Verreaux's sifaka (Propithecus verreauxi) and the cathemeral red-fronted lemur (Eulemur rufifrons) can be found here. Among the many other mammal species, there are also locally endemic species (the giant jumping rat Hypogeomys antimena and the narrow-striped mongoose Mungotictis decemlineata), as well as in the rich bird and herpetofauna (the white-breasted mesite Mesitornis variegatus and the flat-tailed tortoise Pyxis planicauda).