The smell is unbearable and there’s steady passing of trains as the railway track is adjacent to the pond filled with sewage water. Despite the polluted water and the noise, this pond located in an industrial area in Mundka, a semi rural location in north-west Delhi city, attracts at least 22 species of birds. “Frankly, I wasn’t expecting to see these many birds here,” recalls Prakhar Rawal, of the barely two to three hectare water body. Besides the regular water birds, the master’s student from Amity Institute of Forestry and Wildlife observed even near threatened species like black tailed Godwits and Black-headed ibis.
Contrary to common belief, the ponds in Delhi city seem to be supporting a thriving avian diversity. A recent study, published in the journal Biological Conservation last month, highlights these ponds attracting 37 per cent of the city’s bird species recorded in the last 40 years. There are around 600 ponds, varying from two to five hectares in size, which constitute a mere 0.5 per cent of of Delhi’s surface area of Delhi city.
The study is a first of its kind in studying ponds in highly dense urban setting, which are assumed to be bereft of attracting any wildlife. In fact, it’s the highest bird diversity recorded in urban ponds in the world, the study states. The other co authors of the paper include Rawal’s guide Murali Krishna Chatakonda, and Nature Conservation Foundation’s (NCF) Swati Kittur and KS Gopi Sundar.
The three month study, conducted during the migratory season (January till the covid-19 lockdown in March) earlier last year, selected 39 ponds in the city that were representative of the landscape and bird diversity. This included temple ponds, ponds that were part of a park, agriculture ponds, ponds that had once been large but reduced due to land development or encroachment, etc.
“The findings came as a complete surprise to us. Delhi is one of the most crowded cities in the world. One wouldn’t have thought there were so many ponds and that these ponds attracted any birds. But we noted 177 species. In fact, we had recorded 60 species by the fifth pond itself,” KS Gopi Sundar, scientist, cranes and wetlands, Nature Conservation Foundation (NCF).
The study also dispelled the common belief that city water bodies are highly polluted and ridden with garbage. If one had to rate the ponds between one and five, with one being clean and five being highly chocked with garbage, Gopi Sundar said, the ponds were seen to be two or three on average.
The study comes at a time when the city’s new masterplan proposal is considering concretizing these waterbodies into tanks for management of sewage and solid waste management. “No one knew how valuable these ponds are till now.
Fortunately, the old masterplan prevents any construction from happening on ponds. That happy accident of policy has lead to this happy accident to species richness we see today,” he says. Urban fresh water wetlands are the most endangered waterbodies in the world, and there is a need to protect them, he adds.
While it’s a preliminary study, there is a need to do more research on why and how these ponds supported the biodiversity of the city. “We need to go beyond generalizations that focus on large waterbodies and consider these as biodiversity hotspots. These ponds have somehow continued to support an ecosystem despite human intervention in beautifying pond in some cases, or completing neglecting others,” he says.
The study suggests that in order to protect these ponds, one need not look at big changes, small tweaks will help them thrive. For instance, avoid concretising the land around the ponds, allowing reeds and grass to grow in shallow waters, and even create artificial islands like dead tree or fountain too attract birds. Interestingly, ponds that had an island, either natural or artificial, had 11 more species visiting it.
It’s also important to not make a genearlised management guideline for all the ponds as the study found that the habitat and characteristics of no two ponds were alike, Gopi Sundar points out. "Each was unique and diverse. Perhaps, this diversity is responsible for this kind supporting the biodiversity, and therefore, shouldn’t’ be managed with one guideline,” he says.