Articles by Aakarsh Yohaan

During the Open City biodiversity datajam held in December 2025, our group examined the ecological trends around Bengaluru’s lakes. Our analysis suggests a majority of waterbirds are declining across the city's lakes. Earlier, we addressed crucial questions on how migrant and resident waterbirds are surviving across 14 of Bengaluru’s lakes, how the shape of the lakes influence microhabitats, and how a scoring system can be used to record the decline in lake quality and bird populations. The last of our four-part series turns its attention to an individual site. As part of this study of waterbirds in 14 city lakes,…

While bird detection trends over the years clearly point to the decline of Bengaluru’s shoreline and vegetated-edge habitats, numbers alone tell only part of the story. In Part 3 of this four-part series on the state of the city's waterbirds, we have used a scoring system to understand how stressed the lakes and the microhabitats within the lake are, based on the bird diversity they support. We explore how lake shape, permanent inundation and shifts in citizen-led management might explain why some lakes may thrive as wetlands while others collapse.  For instance, at Kasavanahalli, the Pied Kingfisher and the Coot…

Since Bengaluru’s lakes were formed by damming water flowing down valleys, they are typically wedge-shaped, with a gentle slope and a deep basin towards the embankment. This promotes the growth of diverse vegetation and animals, each adapted to a particular water depth. The result is a natural zonation – reedbeds and shoreline vegetation at the edges, floating and submerged vegetation in the middle, and open water at the deepest end. During the Open City biodiversity datajam held in December 2025, our group examined the ecological trends around Bengaluru’s lakes. In an earlier article, we examined how migrant and resident waterbirds…

Lying at an altitude of 920 metres in the rain-shadow area of the Western Ghats, Bengaluru’s geography and climate do not support a perennial natural water source. Instead, a north-south ridge divides the city into three primary valleys: Hebbal, Koramangala-Challagatta, and Vrishabhavathi. Rainwater draining down these slopes feeds a network of small streams — forming a cascading lake system that the city historically relied on for its water supply. During the Open City biodiversity datajam held in December 2025, our group examined the ecological trends around Bengaluru's lakes. Data on insects, spiders and flora on platforms like iNaturalist were insufficient…