Advertisement hoardings and electric cable or meter boxes were also preferred nesting sites for house sparrows. File | Photo Credit: K. Murali Kumar

Most urban sparrows prefer to nest in shop shutters and avoid paved zones and commercial buildings with glass facades, separate studies by a team of zoologists in two different journals have revealed.

The studies by Anukul Nath, Hilloljyoti Singha, Minarul Haque and Bibhuti P. Lahkar, carried out over three months in Guwahati, were published in Urban Ecosystem and Proceedings of Zoological Society.

The Indian subcontinent is home to six species of sparrows, but the house sparrow ( Passer domesticus) and Eurasian tree sparrow ( Passer montanus) are more widespread in the country. These two species share human habitats in many parts of the Northeast, the density of the house sparrow being 29.15 individuals per hectare compared to 9.51 individuals per hectare in the case of the tree sparrows.

The zoologists found 63.64% of the 106 sparrow nests—each up to five metres in height—they recorded to be solitary. About 31% of these nests were in shutters of mostly commercial establishments followed by 20% in “concrete walls associated with water pipes”.

The next preferred urban nesting sites were advertisement hoardings (12%) and electric cable or meter boxes (11%). “This indicates the adaptive nature of the species to a modified environment,” the study titled ‘Nesting in a Crowd’ said.

The study on “Sparrows in Urban Complexity” said the birds tend to avoid shopping centres with glass facades in areas where urbanisation had reached a peak. They also stayed away from paved patches devoid of natural vegetation.

“The habitat patch selection for nesting might be a response to food availability or protection against abiotic factors. The shopping centres with glass facades do not provide much space for placing the nests,” the study said, warning that such structures would be a major threat to the breeding of sparrows in the near future.

The studies indicated that the sparrows could be effective natural controllers of mosquito in urban spaces. Some nests were near open drains.

“Sparrows were found to feed their chicks with mosquito larvae from the open drains,” the study on nesting said. Nearest vegetation patches and food shops offering insects were also found to be factors behind the selection of nesting sites.

The studies found the sparrows to be largely associated with complex urban structures, concluding with a call for “integrative management of urban areas” for implementing policies addressing the conservation of avifauna in cities.

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Printable version | Mar 27, 2022 2:12:26 pm | https://www.thehindu.com/news/national/other-states/shop-shutters-shelter-most-urban-sparrows/article65264521.ece