Limited conservation value of traveller’s palm ( Ravenala spp.) on post-forest land in north-eastern Madagascar

Abstract

Traveller’s palm ( Ravenala spp.; Strelitziaceae) is an arborescent herb endemic to Madagascar, known as ravinala and widely utilised by local communities. Although ravinala often dominates formerly forested land in north-eastern Madagascar, little is known about its density, structural properties or importance for wildlife. Using satellite imagery (WorldView-2) combined with terrestrial inventories, we found a median of 4 ravinala ha ⁻¹ across the 2,500 ha study area and 116 ravinala ha ⁻¹ in ravinala-dominated land (interquartile range = 7 and 88, respectively). We recorded six amphibian and 11 reptile species, with reptiles accounting for most encounters (573 vs 74). Mammals were detected in ravinala only 24 times over 4,195 camera-days. Dwarf lemurs visited ravinala ∼15 times less frequently than co-occurring trees. Four bird species were recorded in ravinala, whereas six species visited neighbouring trees 10 times more frequently. Overall, ravinala was highly abundant in formerly forested land but, except for reptiles, supported comparatively low vertebrate visitation, suggesting limited value as a habitat plant for vertebrate biodiversity. Wildlife diversity in ravinala-dominated land may thus benefit from enrichment with trees.