Sri Lanka, April 13 -- The sound of the Asian Koel or cuckoo, traditionally signalling the arrival of the Sinhala and Tamil New Year season in the month of Bak (April), is occurring at different times this year compared to previous years. Environmentalists point out this shift in the bird's vocal patterns.

There is an enduring bond between the song of the cuckoo bird and the New Year festive season, much like traditional folk games and sweets. The Koel, or Kokilaya, is considered a brood parasite because it lays its eggs in the nests of other birds.

Environmentalists explain that the bird sings most frequently during the month of Bak to attract mates. While the appearance and sound of the Koel are commonly used in modern New Year advert...