Amphibians are the most threatened vertebrates on the planet (about 41 percent), more threatened than birds (13 percent), mammals (27 percent) and reptiles (21 percent). In the last four decades, amphibian populations have declined by 80 percent, with about 37 species reported extinct. The most significant contributor towards these declines is habitat change and degradation. Habitat loss through rapid, unplanned urban changes that homogenise a piece of land with infrastructure, artificial lights, noise, roads, traffic and trash has led to decreased amphibian population and local extinctions. Such land use and land cover changes impact almost 88 percent of the threatened amphibians globally.

My thesis assessed several anthropogenic stressors within rapidly urbanising areas from a global, regional and local perspective. Studies on the impacts of anthropogenic stressors from the global south, including India, are insubstantial despite these countries being megadiverse. India holds one of the largest populations of endemic amphibians, with more than 100 threatened species such as Micrixalus genus (or dancing frogs), endemic to the Western Ghats of India, is one of the top ten threatened genera of the world.

As part of the thesis, a detailed literature review was carried out, which identified 12 major anthropogenic stressors (e.g., roads, traffic, city lights, aeroplane noises, and so on) that impact amphibians multifariously. Studies on each of these stressors were filtered to assess the impacts of each of these stressors on amphibian behaviour, richness and abundance. All the identified anthropogenic stressors congregated within urban areas, making these areas synonymous with the erosion of biological diversity, even causing the complete local extinction of the amphibian population. Stressors across rapidly developing urban areas show a direct or indirect impact on amphibians' feeding, migration and reproductive behaviour. The presence of anthropogenic stressors within urbanising areas significantly reduces the presence of amphibians. However, generalist and opportunistic feeder species occupy several suitable microhabitats once occupied by native, diverse species. This phenomenon is widespread and documented in numerous developed countries of the Global North. However, data from neotropics, including that from India, remains sparse. In my PhD thesis, I addressed this knowledge gap by a combination of (a) a detailed field-based study on the impacts of urban anthropogenic stressors on amphibian communities and threatened dancing frog Micrixalus kottigeharensis across rapidly urbanising laterite plateaus on the foothills and within the moist evergreen forests of India's Western Ghats, (b) documenting malformed amphibians across India via citizen science, literature survey and field-based studies and (c) semi-structured interviews to understand people's perception, attitudes and knowledge on amphibian conservation in India.

Chapter 2 of my thesis reports 19 species of amphibians on the lateritic plateaus along disturbance gradient and correlated with the habitat and environmental variables. I then used a three-table ordination method that allows a direct ordination of species' presence, life history traits, and various climatic and environmental variables into a model to document change in amphibian species' presence along a 30 km urbanising gradient. The model output shows significant associations between species presence, traits and environmental variables. A positive association was seen in the presence of fossorial and arboreal frogs like Uperedon mormoratus and Rhacophorus malabaricus away from the city centre, showing their dependence on specialised microhabitats. Species in the 'Not Evaluated' and 'Endangered' categories show a negative relationship with anthropogenic stressors in the city centre. These species occupy areas away from the city centre, showing their dependence on microhabitats and specific climatic conditions that are seen away from the anthropogenic chaos in the urban core.

Chapter 3 highlights the ecology and threats to an endangered and EDGE species, the dancing frog, Micrixalus kottigeharensis, that is endemic to the central Western Ghats. This frog species has specialised habitat requirements of slow-moving streams and >70% canopy cover for laying eggs and development of fossorial tadpoles. The distribution model shows that the suitability area increases marginally with anthropogenic stressors like land cover changes and human population densities. However, future climate change models show a significant decrease in suitability due to erratic monsoons, leading to unfavourable climatic conditions. Linear models show that M. kottigeharensis presence is largely determined by humidity, stream rock temperature and weather (drizzle). One of the direct impacts of anthropogenic activities on amphibians is amphibian malformations, which are highlighted in Chapter 4. I recorded 65 reports of malformed individuals from across the country, identifying and documenting each of the deformities. Lastly, I evaluated the knowledge, attitude and perceptions of people towards the conservation of amphibians. My survey showed a need for more awareness about amphibians as people largely remain unaware of the basic knowledge. My survey also shows a significant positive effect of gender and age on the perceptions and attitudes of people towards frogs.

Overall, this study significantly contributes to the underpinnings of urban biodiversity in India, focusing on amphibians. There is a need for a nuanced approach towards conserving amphibians across varied, changing landscapes. For the long-term sustenance of amphibian diversity, there is an urgent need to understand and mitigate anthropogenic stressors linked to rapid urbanisation.