Large numbers of yellow and white butterflies flying in the same direction have been observed in Colombo and several other parts of the country since last week.
Researchers studying butterflies identify this phenomenon as butterfly migration, during which large numbers of butterflies travel together in a particular direction.
The butterflies observed belong mainly to the Lemon Emigrant species, a common butterfly in Sri Lanka. Experts point out that this migration is generally observed during November and December.
However, this year’s migration has been particularly noticeable, with unusually large numbers of butterflies being recorded.
Environmental lawyer and conservationist Jagath Gunawardena stated that the phenomenon would not be limited to a single day and that the migration was likely to continue over the coming days.
According to a statement published on his Facebook page, this migration marks the beginning of an annual movement traditionally observed during November and December.
Based on historical records and studies conducted since 1987, approximately 70 butterfly species have been identified as participating in this migration.
The initial stages usually involve the Lemon Emigrant and Mottled Emigrant species, while additional species join as the migration progresses.
Gunawardena further noted that butterfly migration had declined considerably in recent years, with some years recording almost no noticeable migration. Before this year, a similarly significant migration was observed in November 2014.
He also highlighted the presence of small numbers of Painted Lady butterflies, normally found in Sri Lanka’s central highlands, around Colombo during the 2014 migration.
Furthermore, the Orange Migrant species has joined the migration in recent years. First recorded in Sri Lanka around two decades ago, this species is believed to have entered the country through imported ornamental plants.
Gunawardena explained that the Lemon Emigrant species (Catopsilia pomona) displays several distinct colour variations, which explains why butterflies ranging from white and pale yellow to deep yellow can be seen flying together.
He also noted that observations made at one location between 9.30 a.m. and 3.30 p.m. revealed approximately 45 to 70 butterflies passing through within a single minute.
The conservationist encouraged the public to observe this unusually prominent natural phenomenon and enjoy the opportunity to witness the seasonal butterfly migration.
