Malaka Rodrigo in Sunday Times, 18 August 2019, where the title runs “Out of the blue, a visitor is blown in by the monsoon”
An unusually large bird found this week on Muthu Panthiya island in Chilaw drew crowds as it had never been observed on land. Stricken by curiosity, the villagers caught the bird and handed over to the Anawilndawa wildlife office. The bird, blackish with white underparts, had a very long, hooked beak and a wide wingspan and looked clumsy on the land, unable to perch properly. It was later identified as a frigatebird – a large seabird inhabiting tropical and subtropical ocean regions.
Frigate birds are occasionally observed flying on the sky, but it is very rare to find one on land in Sri Lanka. Named after a fast warship, frigate birds are fast on the wing, sometimes attacking other birds to steal their fish catch and snatching baby birds from other seabird colonies.
There are five species, and experts believe this bird could be a Christmas Island frigatebird (Fregata andrewsi) or great frigatebird (Fregata minor). Seabird expert Gary Allport of BirdLife International identified the bird in Chilaw through photographs as a female greater frigate bird aged two or three years. “Greater frigatebirds are common in the Maldives and the strong monsoon winds could have assisted the bird’s passage from the Maldives to Sri Lanka [about 600km],” seabird expert Rex I. De Silva said.
“The presence of a Christmas Island frigate bird would be more difficult to explain as the bird would have to battle strong monsoon headwinds for approximately 3,600km to get here”.
Mr. De Silva said frigate birds are notoriously difficult to identify as in a particular growth phase one species could resemble another in a different phase. Frigate birds have long and pointed wings that can span up to 2.3metres (7.5 feet). This is the ratio of largest wing area to body weight than any other bird in the world. The birds feed on fish picked from the ocean’s surface while in flight.
The recent strong monsoon winds and weather might have helped bring the frigatebird to Sri Lanka’s western shores. Just a day prior to its discovery in Chilaw, Mr. De Silva, on his social media platform, “Seabird Watch (Sri Lanka)”, posted a note that the bad weather should be ideal for observing the seabirds as this is also the period of a mass seabird migration.
“August-September is in fact the best time to observe the great mass migration of seabirds. During the peak in September as many as 3,000-4,000 bridled terns (Sterna anaethetus) fly southwards within sight of shore in one hour,” states Mr. De Silva who has studied this fascinating phenomenon over many years.
Many seabirds take part in long annual migrations, crossing the equator after the breeding season. Nearly 50 seabird species have been recorded on the west coast of Sri Lanka.
One of the main studies conducted by Seabird Watch (Sri Lanka), a 13-year study of the mass migration of bridled terns off the west coast, is the most comprehensives and long-lasting study on seabirds in the northern Indian Ocean. BirdLife International, the umbrella organisation of world’s bird conservation organisations states seabirds have become the world’s most threatened bird group, recording steep declines in populations almost everywhere.
There are only 2,400-4,800 mature Christmas Island frigate birds thought to remain in the wild according to the International Union for the Conservation of Nature.