A study on the nesting habits of house sparrows in the Nilgiris has highlighted certain interesting behavioural changes among the birds, and also outlined a few causes of concern for their future conservation.
In a study designed to ascertain the type of nests that house sparrows most prefer to nest in, research scholars Samson Arockianathan and A. Jayaraman from the Department of Wildlife Biology at the Government Arts College in Udhagamandalam, placed nests made of PVC pipes, wooden boxes, bamboo pieces, shoe boxes, mud pots and tailor-made bird boxes in three different locations where the birds were found in Udhagamandalam. Their findings were published in an international journal – International Studies on Sparrows.
“The boxes, numbering more than 650 in total, were kept in locations classified as being near the market, in residential zones and at educational institutions, like schools and colleges,” said B. Ramakrishnan, Assistant Professor at the Department of Zoology and Wildlife Biology at the Government Arts College, who guided the research scholars.
The researchers discovered that even though the the market area had higher footfall from humans and was busier, the birds preferred to nest in these areas, populating the nests in around 3-4 days after they were first kept there.
“In comparison, it took the sparrows longer to adopt nests that were placed in residential areas, while they only occupied nests in educational institutions located near canteens, while avoiding most altogether” said Mr. Ramakrishnan.
The researchers said that the findings seemed to indicate that the birds preferred to nest in the market area because of the availability of food. “We have noticed that the diet of sparrows consists of grains and they also prefer a high-protein diet to raise their chicks, which they source from insects and flies, and meat from stalls in the market,” said Mr. Ramakrishnan, adding that a high-protein diet ensures that the birds’ offspring gain weight more quickly.
This concentration of the sparrow population in a few pockets could be problematic in the long-run, said Mr. Samson Arockianathan, who said that in-breeding, and a lack of genetic diversity among the population was already manifesting itself in the sparrows being monitored in the market area. “We have recorded individuals with albinism and melanism, which are clear indicators that they are in-breeding and are not coming into contact with other birds, which could lead to a dramatic crash in their population in the future,” said Mr. Arockianathan.
On International Sparrow Day, the researchers urged the public to adopt strategies that will allow more sparrows to thrive in residential areas, ensuring that there are more chances of breeding among the different populations and more genetic diversity among the birds.
“If each individual house can keep a small pot of water for the birds during the summer, and some grains for them to feed on, it will be quite useful in ensuring the survival of the birds,” said Mr. Ramakrishnan, who said that concrete buildings had also led to chances for sparrows nesting in residential areas diminishing.
“If housing plans too can incorporate small designs to allow sparrows to nest in the buildings, each household can ensure the survival of at least two to three pairs of house sparrows,” he added.
