Burong olok-olok (jester bird) is the brown gannet
A. W. Hamilton’s brief note identifies the Malayan bird name burong olok-olok (literally “jester-bird”) as the Brown Gannet, Sula sula (Linn.).
Summary
Hamilton notes that Wilkinson’s Dictionary listed burong olok-olok as an unidentified bird. He reports that Mr. H. C. Robinson kindly identified it for him as the Brown Gannet. The bird is described as a dark-plumaged sea bird with webbed feet, known locally as olok-olok in Kedah, where solitary specimens are typically encountered at sea off the Kedah coast in company with flocks of gulls (p. 260).