Dietary preference of Alien Invasive Anurans (Rhinella marina, Hoplobatrachus rugulosus, and Kaloula pulchra) in Butuan City, Northeastern Mindanao, Philippines

Abstract

Invasive anuran species (IAS) threaten the native anuran species as they compete for food sources. The diet of the three IAS, Rhinella marina, Kaloula pulchra, and Hoplobatrachus rugulosus, were collected from different localities in Butuan City. The gut collected from 91 individuals of IAS, i.e., R. marina (n=80), H. rugulosus (n=10), and K. pulchra (n=1) were examined for food items using a dissecting microscope. The R. marina had the most recorded prey items, consisting of plant materials, pebbles, insects, and reptile-like species, while K. pulchra prefers small and slow-moving insects. Hoplobatrachus rugulosus, which also preferred insects on their diet, exhibited frog predation. Among the food categories, plant materials (56%) had the highest percentage, followed by invertebrates (47%), other organic and inorganic materials (12%), and vertebrates (1%). Formicidae, Coleoptera, and Odonata have the highest percentage among the invertebrate prey types. The assessed amphibians feed on locally available prey, generally insects, and suggest potential competition for food resources with native anuran populations.