New Delhi, March 10 : In one of the only studies in the world that has documented the roosting and nesting waterbird community inside Udaipur city in Rajasthan reveals the city famous for its centuries-old artificial lakes is home to 17 waterbird species roosting and 12 nesting species. And they used 23 species of trees for these two activities.

Trees used for both activities were in locations that had a relatively smaller amount of built up area (compared to random locations), suggesting the waterbirds were trying to find less noisy and disturbed areas for these activities.

The study says waterbirds were also choosing sites that had a lot of wetlands nearby, indicating the artificial wetlands of the city were attractive to these species to conduct their most critical activities.

The research was done as part of the PhD graduate thesis of Kanishka Mehta from the Mohanlal Sukhadia University in Udaipur. The thesis was advised by Swati Kittur, Vijay Koli and K. S. Gopi Sundar, the Co-chair of the IUCN Stork, Ibis and Spoonbill Specialist Group.

'The research focused on Udaipur and asked the broad question of whether the city is providing refugia for waterbirds. The city is famous for its artificial lakes that erstwhile kings constructed to cool the city during the summer months. We, therefore, wanted to know if these artificial wetlands were attracting waterbirds,' Sundar told IANS on Sunday.

Specifically, the study addressed the question of roosting and nesting sites of waterbirds in the entire city of Udaipur, which has been nominated for the Wetland City Accreditation (WCA) scheme under the Ramsar Convention.

'Some of the questions we wanted to answer are: Where did waterbirds in Udaipur roost and where did they nest? Did they use the same sites for both activities? What sort of trees or other structures were used to roost and nest? Which species of waterbirds were using Udaipur for roosting and which ones were nesting within the city limits'? he explains.

The study was unusual in that it documented the entire waterbird assemblage in the city that was roosting or nesting inside the city.

A waterbird is a bird that lives near and walks or swims in water, especially rivers or lakes.

'Such studies are very rare,' Sundar says. In keeping the focus relatively wide, the study discovered the following species roosting and nesting inside Udaipur: the little cormorant, Indian cormorant, great cormorant, little egret, intermediate egret, great egret, cattle egret, pond heron, grey heron, purple heron, black-crowned night heron, glossy ibis, black-headed ibis, red-naped ibis, painted stork, Asian openbill stork, and the woolly-necked stork.

The bird species with the highest number of roosts in the city were the pond heron, cattle egret and the red-naped ibis.

The bird species with the highest number of nest sites in the city were the cattle egret, red-naped ibis and the Asian openbill stork.

Researcher Kanishka Mehta, who has now completed her doctorate, says there is some information previously from other cities around the world documenting nesting waterbirds, but studying the full assemblage of roosting waterbirds has never been attempted before.

Also, this study covered the full city. Usually, a part of the city, such as waterbodies, is covered for studies. 'Our study is, therefore, able to provide insights on what aspects of the entire city are being sought after by different waterbird species,' says Vijay Koli, assistant professor at Mohanlal Sukhadia University.

The study was conducted between December 2020 and September 2021. The effort, therefore, covered one full nesting season, and also provided adequate time to understand where waterbirds were roosting in the city.

Sundar explains urban ecology is a relatively new subject in India, and most of the work has been carried out on tree diversity, and in cities such as Bangalore and Delhi, that are mega cities.

Cities of India, and other cities in the tropics and subtropics, are being discovered to have a high level of diversity. This has been surprising for scientists since most of the work on cities has been from cities in temperate areas where diversity is very low inside the city.

Studies in temperate regions have given rise to assumptions that crowded cities of the tropics and subtropics must not have too much biodiversity due to the disturbance that people's activities provide for wild animals like birds.

The few cities where such studies have been conducted in India have shown fairly high levels of bird diversity. This study in Udaipur is one of the first in a small city of India that has been conducted across the whole city using careful methods.

'Since waterbird nesting and roosting has not been studied in other Indian cities, we are unable to compare our findings. However, with the results seen in Udaipur, we suspect that cities in India are very important locations for waterbirds. This has been entirely overlooked by scientists and conservation groups and is an exciting discovery,' he explains.

Indian cities are showing themselves to be very important refugia for urban wildlife. Some of this is worrying to people since species like leopards can cause some conflict and injury to people.

Other wild species like birds, bees and butterflies are, however, not dangerous and also very important for ecological functions.

'The government should, therefore, be considering our cities as being multifunctional systems where elements planned for humans can also be useful for a number of wild species. Considering cities to be multifunctional in policies will have multiple benefits. Interactions with nature are an important element of mental wellbeing for humans, which means that city planning should ideally consider both humans and wildlife of that particular region.

'Cities in Assam can be planned for wildlife found in that state, and Udaipur's planners can focus on wildlife such as waterbirds that are resident in the city,' adds Sundar.

The study showed the enormous importance of old trees and also dead trees as waterbird roost and nest sites. As trees age, notwithstanding whether they are exotic species such as eucalyptus, or native ones such as neem, they become invaluable habitats inside the city.

Old trees used to be a common element of roads as roadside trees planted to shade travelers. Udaipur's waterbirds still use old roadside trees for roosting despite the enormous disturbance that traffic could be causing.

(Vishal Gulati can be contacted at gulatiians@gmail.com)

/IANS