Predation on the foam nest of Polypedates sp. by Euphlyctis sp

IntroductionPredation is one of the most widespread foraging behaviour prevalent in the animal kingdom (Taylor, 1984; Curio, 1976). Amphibians, with respect to predation, generally prefer waiting for prey while being stationary as a method for foraging [i.e. ambush predation] (Duellman & Trueb, 1986). It is to be noted here that visual detection is the primary method with which anurans spot prey (Freed, 1988).Regarding foam nest at least six families of amphibians are known to produce such breeding refuge for egg laying, namely: Hylidae, Hyperoliidae, Leptodactylidae, Microhylidae, Myobatrachidae, and Rhacophoridae (Andreone et al., 2005; Haddad et al, 1990; Haddad & Prado, 2005). Various hypothetical functions have been attributed to foam nests of frogs. These include inhibition to the growth of tadpoles (Pissano & Del Rio, 1968), resistance to desiccation (Ryan, 1985; Downie, 1988), improvement towards the supply of respiratory gases (Seymour & Lovebridge, 1994), regulation of temperature (Downie, 1988), predator defense (Downie, 1988 & 1990), as a source of food (Tanaka & Nishihira, 1987), and also growth acceleration (Prado et al., 2005). Predation on foam nest has previously been reported, where non anuran species has been seen to predate on these nests in various conditions (Lingnau & De-Bernardo, 2006; Villa et al., 1982).In this note we report a predation behaviour on the foam nest of one species of anuran (Polypedates) by another species (Euphlyctis).Observation:An individual of Euphlyctis sp. was observed feeding on a foam nest of Polypedates sp. on 14th of March, 2020 at 09:42 hrs (Image 1). The observation was made on top of Barunei Hills, in the Khurda district of the state of Odisha in India (20º09'27.6'' N and 85º38'35.7'' E, 227m ASL elevation). The weather was clear and sunny with an ambient temperature of 32ºC. It was an opportunistic observation made while inspecting amphibians in an ephemeral pool of water inside a small cave on top of a stunted hill. The pit was observed to harbour a community of three species of anurans—Euphlyctis sp., Polypedates sp. and a Duttaphrynus sp. We observed an individual of Euphlyctis eating, with gulping motion, from one of the foam nest of the Polypedates sp. that was at the side of the water pool on rock substratum, intermittently. The observation was captured in video and photographs were created using the snapshot from the videos for visual reference. The image and video files were submitted to the Le