KANCHANPUR: Sparrows that used to be seen in large numbers around houses and farms in the district have diminished in numbers over the years.

The most common birds, sparrows, have started feeling the pressure of climate change and are on the verge of disappearance from Kanchanpur and surrounding areas.

With the increase in summer heat, the thatched roofs of houses where the sparrows live and build their nests also become heated, thereby spoiling the eggs in the nests. The birds themselves are succumbing to excessive heat.

Locals say that flocks of sparrows used to be seen before but these days they are only visible in limited numbers.

Temperature in Tarai districts including Kanchanpur is found to be rising and reaching up to 55 degrees Celsius for some years.

"In houses of traditional structure, there used to be enough space in the roof for the sparrows to build their nests and roost on. But the modern cemented houses do not have that type of roofs congenial to the sparrows. So the bird population is on a decline," Bahadur Singh Mahara, an environment expert, said.

Mahara added that sparrows are on the verge of disappearance also because of the increasing sound, air and soil pollution.

"Rampant use of pesticides and fertilisers on crops is also one of the causes for diminishing number of sparrows because the birds' diet comprising small insects found in the soil are killed by pesticides. The grains on which the sparrows feed also have traces of pesticides," Mahara explained.

According to him, sparrows have also started dying after feeding on the insects and grass hoppers that have perished on exposure to insecticides.

"Water in the streams is also polluted due to industrial effluent that is directly released into these water bodies. Sparrows drink the polluted water from these streams and drains, and therefore die," said Tek Bahadur Hamal, a local.

A study shows that street lights and mobile towers also contribute in the decline of the birds. Sparrows cannot distinguish between day and night due to street lights, and lose direction from the radio waves that emanate from mobile phone towers, both affecting their life-span.

A sparrow lives for three to 13 years.