Green matters: Dietary assessment of a reptile community using DNA metabarcoding

Abstract

DNA metabarcoding is widely used for diet characterization and is becoming increasingly important for biodiversity conservation, allowing the understanding of trophic networks and community assemblies. However, to our knowledge, few studies have used this approach to investigate trophic interactions for whole communities and none for reptiles. In particular, few studies have examined the diet composition of Saudi Arabian reptiles, and all have used classical methods only. Therefore, in this work, a non-invasive approach using DNA metabarcoding of faecal pellets was implemented to investigate the diet composition of the reptile community of Wadi Ashar, in AlUla County, north-western Saudi Arabia Kingdom. In the overall diet composition of the community, arthropods were present in 90% of the samples, and plants were present in 63%, revealing the unforeseen importance of plants to this community as a secondary, but also a primary dietary item. For some species, this is the first time that plants have been reported in their diet. A significant effect of reptile body size on diet composition was also demonstrated, indicating its strong influence on prey selection and resource partitioning in the community. This study highlights the importance of community assessments and the power of combining these with non-invasive DNA metabarcoding to accurately assess biodiversity and feeding habits, revealing unknown ecological interactions of often neglected groups. This revolutionary tool for conservation and management provided rapid and holistic information at relatively low costs, allowing to inform local authorities about which elements are central to the sustainable management of the Wadi Ashar community.