Thousands of yellow butterflies across Sri Lanka; scientists explain

Large numbers of yellow and white butterflies flying in many parts of Sri Lanka in recent days have drawn public attention.

Videos and photos showing thousands of butterflies flying in groups, mostly in one direction, in areas including Colombo, Galle and Ratnapura are spreading on social media.

Scientists explain this as a natural seasonal butterfly migration linked to the monsoon, changes in vegetation and breeding patterns.

Experts say Sri Lanka generally sees a major migration during October-December and a smaller one in March-April. Rain during the monsoon change spurs the growth of plants that give the butterflies food and breeding habitat, which is why the phenomenon appears.