The small parks in neighbourhoods of the erstwhile garden city may not just be for recreation and walkers, but its design may play a key role in protecting Bengaluru’s winged residents.
Size, it seems, doesn’t matter; but a number of parks in close proximity may play a key role in encouraging the presence of birds and butterflies, finds a study by Ashoka Trust for Research in Ecology and Environment (ATREE), which was published recently in the journal Plos One .
Researchers Savitha Swamy and Soubadra Devy, along with Harini Nagendra of Azim Premji University, surveyed 37 neighbourhood parks in four zones of the city. These included 11 small (less than 1,000 sq.m.), medium (1,000 to 1,500 sq.m.) and 12 large parks (greater than 5,000 sq.m.). The city’s large green spaces — Cubbon Park, Lalbagh, Indian Institute of Science and Gandhi Krishi Vigyana Kendra (GKVK) — were also selected and mapped.
‘Biodiversity fondness survey’
For biodiversity mapping, researchers conducted a ‘biodiversity fondness survey’ where they asked residents and walkers about the creatures they liked to see in parks. Birds and butterflies ranked high in the 563 surveys while insects were low on the list. These findings became the base for a biodiversity survey.
Their survey found 55 tree species — nearly half of which are non-native — 45 species of birds, 41 species of butterflies and 68 species of insects in the parks. Tree density and canopies attracted birds, shrubs brought in butterflies, while the presence of lawns saw a large number of insect species using parks.
Not only were these relatively compact spaces able to harbour biodiversity, the study showed that park size did not directly impact species richness or abundance. Instead, other factors — particularly, presence of other parks in the neighbourhood and a spread out green cover — played a role in attracting larger variety of birds and butterflies to the parks.
Importantly, even without a large green space nearby, a large network of neighbourhood parks can support a high-species richness while a small network of neighbourhood parks needs a large green space to support larger number of species.
“(Despite) their limited size, if neighbourhood parks are connected through the development of green links, they could contribute significantly towards conserving biodiversity within the city,” says Ms. Soubadra.
The findings can give pointers to urban planners to ensure the city’s parks play an important social role as well as a role in biodiversity conservation, said Ms. Nagendra. “Butterflies and insects respond to greenery within 1km of the parks while birds respond to flora within a 5km radius. By filling the gaps, we can build a network of greenery that encourages these species within the city,” she said.