Thousands of barn swallows (Hirundo rustica), migrating south to escape winter in the Northern Hemisphere, started arriving in large flocks in Yogyakarta last week.

The birds can be seen perched on power lines, trees and buildings along Jalan Mayor Suryotomo near the Gondomanan intersection, 600 meters from the city's famous Malioboro shopping district.

The passerine birds spend summer in the Russian Far East, northern China, Mongolia, the Korean Peninsula and Japan and fly south in search of warmer climates with plenty of food and water at the beginning of winter.

The forked-tail birds with blue backs gather in large flocks and fly off before 5 a.m. every day before returning to Jalan Mayor Suryotomo by around noon.

The feathered visitors usually stay in Yogyakarta until March, when they migrate north once more.