- A recent study revealed a significant presence of waterbirds roosting and nesting in Udaipur, Rajasthan. A total of 17 species were observed roosting, while 12 species were found nesting.
- Species such as the red-naped Ibis, glossy ibis and woolly-necked storks, which have been scarcely studied, were found nesting and roosting within the city.
- The waterbirds were spotted on 23 species of trees, including neem and eucalyptus, most often those located near or on waterbodies.
Traditionally, crowded cities may seem like unlikely places for wild species to thrive, given the impacts on critical behaviours like roosting and reproduction. However, recent research challenges this assumption, revealing that waterbirds across Africa and South Asia are adapting and even thriving in urban settings, by making use of human-made structures and resources.
Despite this discovery, there remains limited knowledge on how these birds choose sites for crucial activities like roosting and nesting in urban areas. To address this gap, a study was conducted in Udaipur, Rajasthan, to investigate the cues for selecting roosting and nesting sites, and to ascertain if various species of waterbirds employed similar cues.
“In India, research on urban biodiversity and its ecosystem services is notably lacking. This oversight means that cities are rarely considered as wildlife havens. But the reality is different. Our study in Udaipur reveals abundant breeding colonies and waterbird roosting sites within the city. This suggests that we may be missing out on documenting a substantial portion of waterbird populations by solely focusing on wilder habitats,” says K.S. Gopi Sundar, co-chair of the IUCN Stork, Ibis and Spoonbill Specialist Group, and one of the study authors.
Where are Udaipur’s waterbirds?
Nestled in southeastern Rajasthan, Udaipur is surrounded by a diverse landscape, consisting of the ancient Aravalli hills, villages, small towns, scrublands, agricultural lands, and open areas.
The study authors note that there existed limited knowledge regarding Udaipur’s waterbirds, with only a few checklists. “Urban ecology studies are biased towards large and mega cities, with very little work done on small cities of the tropics and sub-tropics,” says Sundar.
They documented waterbirds within Udaipur city limits to assess their roosting and nesting habits. They recorded several species, including 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 woolly-necked stork.
“While certain species like egrets, herons, ibis, and storks have been sporadically spotted nesting in urban areas, our study represents the first comprehensive documentation of the entire waterbird community utilising a small city for both roosting and nesting activities,” says Sundar.
The initial findings of the study revealed a significant presence of waterbirds roosting and nesting within the city limits. A total of 17 species were observed roosting, while 12 species were found nesting. The species most observed roosting in the city were the cattle egret, followed by the red-naped ibis, and the Indian pond heron. A total of 130 nesting locations were also identified, most belonging to the cattle egret, followed by the red-naped ibis, and Asian openbill.
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Roosting and nesting habits of waterbirds
The researchers found that the waterbirds exhibited a preference for roosting and nesting sites near or within water bodies. Roosting sites were frequently found adjacent to bustling roads and in heavily constructed areas. The team’s analysis also incorporated variables such as tree characteristics, land use around trees, and so on. These variables were examined across different spatial scales to gain insight into the preferences of waterbirds in urban environments. At the smallest scale, waterbirds steered clear of buildings near the trees they had chosen for roosting or nesting. At a larger scale, they chose trees located close to wetlands.
Surprisingly, waterbirds displayed flexibility in their choice of trees for roosting and nesting, utilising 23 different tree species. However, most roost and nest sites were observed on the largest trees such as neem, eucalyptus, fig and babul. “We also observed that the waterbirds entirely avoided roosting or nesting on trees found on the Aravalli mountains surrounding and within the city of Udaipur,” says Sundar.
Since research on waterbird roosting and nesting has rarely been conducted, the team held few expectations about what they would discover. However, the observed behaviour of waterbirds aligned with their anticipations of utilising the largest trees, particularly those situated near or within water bodies. “The utilisation of trees along roadsides and in built-up areas was surprising, but highlighted the importance of conserving old trees within cities,” says Sundar.
The researchers feel that cultural norms that appreciate nature and wildlife may partly explain why waterbird roosts and nests were found even near buildings.
“Species such as the red-naped ibis and woolly-necked storks, which have been scarcely studied, were found nesting and roosting within the city. The red-naped ibis, in particular, exhibited no distinct preference for any of the variables used to locate roost and nest sites, suggesting its adaptability to urban environments,” says Sundar. The study challenges assumptions about the species’ ecology and population trends, highlighting the pitfalls of making confident assertions based on limited information.
Similarly, the glossy ibis, another poorly studied waterbird in the region, was previously believed to require relatively undisturbed large wetlands to survive. However, observations revealed its versatility, with individuals even utilising trees beside roads with heavy traffic for roosting.
The road ahead
As Udaipur city expands, the researchers believe it crucial that planning authorities prioritise conservation and greening efforts in urban spaces. “The value of old trees in urban areas cannot be overstated. These trees offer numerous benefits to cities and serve as vital habitats for waterbirds. By safeguarding old trees, we can enhance urban biodiversity and create win-win scenarios for both humans and wildlife,” says Sundar.
The researchers also advocate for preserving all water bodies within and around cities, particularly in places like Udaipur, as they are essential ecosystems supporting diverse life, including waterbirds.
The widening of roads too poses a significant threat to waterbirds as roadside trees are felled. Alternative solutions to road expansion must be sought to preserve trees, especially mature ones that provide essential shade. This may offer birds more nesting opportunities, potentially leading to an increase in waterbird roosting and nesting within Udaipur city.
“The research findings can also guide conservation efforts for other bird species and urban areas. However, the diversity of urban settings across small cities requires customised conservation approaches. Further research in various cities is essential to identify specific strategies for conserving waterbirds and improving urban biodiversity,” says Sundar.
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Banner image: Communal roost of waterbirds in Udaipur. Photo by Kanishka Mehta.
