The Dragon Blood Tree's Gecko (Hemidactylus dracaenacolus)
Dragon blood tree's gecko - a flagship for Socotra
The study area of this project is restricted to the Ma’alah, Diksam and Haggeher mountains of the Socotra Island. This island belongs to the Socotra Archipelago, Yemen, classified in 2008 as a UNESCO world natural heritage site. It is also included in the Horn of Africa Biodiversity Hotspot. It rests in the Arabian Sea 100 km east of Somalia. This is one of the most remote and among the top-five biodiversity rich archipelagos in the world. Its complex geological history, together with its topography, the presence of many different microclimates and habitats and centuries of sustainable traditional management, are considered the main cause of its high biodiversity levels, which includes a high number of endemic genera and species. Reptiles are one of the most prominent vertebrate groups of the archipelago with 31 species and all native species endemic. Reptiles also constitute a keystone group as arthropod predators, as prey for birds, and likely as pollinator or seed dispersers of plants. Besides, some of these reptiles have strict associations with specific habitats. So, its conservation indirectly would protect many others endemic species of fauna and flora.
The target species, Hemidactylus dracaenacolus, is a gecko classified as Critically Endangered by the IUCN due to population and habitat area decline together with its reduced geographic range. The species has only been found in the Diksam Plateau and exclusively on endemic dragon’s blood trees Dracaena cinnabari (see previous report with project number 13055714: Vasconcelos et al. 2014) that is suffering a strong decline and faces the risk of extinction due to overmaturity and overgrazing by introduced goats. Moreover, according to the previous survey, H. dracaenacolus distribution is much smaller than that of dragon’s blood trees, and populations seem to have very low densities in sites where previously were more commonly found (Vasconcelos et al. 2014). This is worrying and deserves further attention. Mountains in Socotra play an important role on the long term persistence of this species and other endemics as constitute a refuge during unsuitable drier and warmer climates. These are speciation centres with several genetic lineages highly divergent identified and presumably yet to be described. Improved/new knowledge on distribution, diet, gecko-tree interactions and population trends is invaluable for understanding ecology and a successful conservation plan.
