In tropical anurans, explosive breeding is a common reproductive strategy. During these events, all sexually receptive individuals simultaneously arrive at breeding sites and invest a single burst of energy into copulation within 24-48 hours. For such specialized breeders, human effects on the landscape can be utterly catastrophic because even a slight change to the environment can render a habitat unsuitable for explosive breeding, which cuts off the animals’ chance at reproduction. Unfortunately, in many tropical landscapes where explosive amphibians breed, land transformation for crop production is all too common. However, few have ever studied how such development impacts explosive breeding behavior in animals. Here, I propose to study effects of human development on explosive breeding events in Common Indian Toads (D. melanostictus) in the Western Ghats in southern India. D. melanostictus is an explosive breeder that inhabits moist forests and urban lowland areas in south and southeast Asia and requires permanent ponds or vernal pools for reproduction and offspring survival. This study system allows us to investigate the anthropogenic effects on the explosive breeding events, and this information can be applied to other specialized breeders (many of which are highly endangered). Additionally, I will incorporate a citizen outreach component to my project where I talk with local farmers to help establish anuran-friendly farming systems.

My study will consist of two parts: field work and interviews. In the field, I will identify three types of sites with different levels of human development: betel nut farms, village edge, and undisturbed stream. Within each site, I will use a simple transect technique to a) count the number of males and females (only males have bright yellow color morphs during the event), b) measure the average size, and c) measure the degree of male color change before/during the breeding. More participating individuals, bigger body size, and brighter male color morph in the farms may suggest promotion of breeding by favorable conditions, such as ditches as gathering sites and ample crop pests as their food source. On the other hand, the opposite results may indicate inhibition by unfavorable characteristics of the farms, such as well-draining soils, use of pesticides, and increased predation risks due to cleared understory. Disproportionate sex ratio across the sites could indicate that development impacts each sex of D. melanostictus differently, and this warrants further investigation.

Another goal of this study is to determine aspects of farm design and practice that can best sustain the toad population without incurring negative impacts on farming. The history of betel nut plantation dates back to the British colonization era, and it is now a prevalent and important commodity – both economically and culturally – for the region. It is therefore critical to respect their farming practices. I will examine what part of farms the toads prefer (e.g. ditches and farm edges) and assess with local farmers the importance of such features to their farming. I will then work with my adviser and his local colleagues in southern India to find ways of disseminating this information into the local farming communities. This project will allow the local community and our team to work together to produce scientifically and practically meaningful knowledge for this community and beyond.

I am a member of the Class of 2025 studying Biology at Brown University. This summer, I will collaborate with Dr. Doris Preininger from the Vienna Zoo in Austria as well as local researchers in the Western Ghats of India on a research project investigating the anthropogenic effects on tropical anuran explosive breeding events. Many tropical animals rely on an annual explosive breeding event, where massive amounts of individuals come together in a short time period to breed. These types of breeding events require certain sets of environmental conditions, such as the onset of monsoon season, but the effects of human land development on such events has hardly been investigated. My project aims to understand the direction and magnitude of anthropogenic effects on explosive breeding events in the Common Indian Toads in India and create a literature basis for endangered species around the world that rely on explosive breeding events. My research will invite the locals to share their personal experiences with the toad population and together establish anuran-friendly land-use practices. I look forward to documenting the impacts of human land development on explosive breeding species and think about creative solutions to reduce human impact on these breeding events with the local community.