Urban sprawl can fundamentally alter local biodiversity, resulting in food web shifts. Consequently, one would expect organisms living in peri-urban areas to experience a functional dietary shift compared to their counterparts inhabiting natural habitats. Here, the diets of two dwarf chameleon species, Bradypodion damaranum and B. ventrale, were assessed using eDNA metabarcoding of faecal material. Both species have well established peri-urban and natural populations, making them well suited for dietary comparisons. Assuming prey assemblages differ between natural and peri-urban areas, chameleons may have enough flexibility to take advantage of new prey resources. This would be reflected in corresponding differences in dietary composition. Two primer combinations amplifying portions of the mitochondrial COI gene, mlCOIintF/jgHCO2198 (universal) and ZBJ-ArtF1c/ZBJ-ArtR2c (arthropod-specific), were used to explore their diets. A total of 40 arthropod prey species and one nematode species were identified from 22 chameleon individuals. The mlCOIintF/jgHCO2198 primers produced a greater number of taxonomic identifications, whereas the ZBJ-ArtF1c/ZBJ-ArtR2c primers identified rarer taxa, with limited taxonomic overlap between primer sets. This suggests that combining multiple primer sets will enhance diversity exploration in future studies, however, relative costs have to be balanced with intended outcomes. Three major soft-bodied insect orders (Neuroptera, Thysanoptera, and Trichoptera) were identified in the dwarf chameleon diets. No significant differences in the composition of prey items were found between peri-urban and natural populations of B. damaranum. A relative abundance of lepidopterans was found in peri-urban B. ventrale populations, however, other prey items remained consistent between populations. Overall, our findings suggest that prey items consumed by the peri-urban population are not overtly different to their natural counterparts.
Adair et al. (Thu,) studied this question.