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.

Parasitic helminths of alien invasive anurans in Butuan City, Northeastern Mindanao, Philippines

“…Site 3, Brgy. Masao (9°00′10.2″N and 125°29′23.0″E) is a coastal area with human settlement, beach resorts, and an adjacent river system ( Torralba et al ., 2022 ). Within each barangay, extensive and opportunistic sampling was employed in collecting invasive anurans from 7:00 to 9:00 P.M., using handling equipment such as gloves and wooden sticks, then placed inside a net bag ( DENR-BMB 2017 ; Jabon et al ., 2019 ).…”

“…However, there are currently no reported infections in K. pulchra. In the Caraga region, Philippines, two invasive species have been identifi ed, which are the commercially edible H. rugulosus and the failed biological control agent, R. marina (Solania & Fernandez-Gamalinda, 2018;Solania et al, 2020;Torralba et al, 2022). It is worth noting that anuran invasion and parasitic infections are more commonly observed in highly urbanized areas, such as Butuan City in the Caraga Region of the Philippines.…”

Symbiotic species diversity can explain invasion success and host–parasite system stability: The case of gammarid hosts

“…Parasites have been linked increasingly with the current global biodiversity crisis and large‐scale anthropogenic disturbances such as climate and habitat change, natural resources overexploitation, pollution, and invasive species (Brian, 2023; Nunn et al, 2003; Tkachenko et al, 2023). Local and global biodiversity losses, and biotic and environmental homogenization put ecosystems under enormous stress, making it critical to understand how the loss, or addition, of species influences the stability and function of the ecosystems on which humans depend (Jaureguiberry et al, 2022; McCann, 2000; Qiao et al, 2023; Torralba et al, 2023). Many experimental and field studies suggest that high biodiversity improves the functioning and stability of ecosystems (McCann, 2000; Qiao et al, 2023).…”