Who does not know about the world of migratory birds ? The event, commonly called World migratory Bird Day ( WMBD ) is performed by the world every year in the month of May to preserve the habitat of migratory birds . In 2012 , the event falls on May 12 to 13 One group of nature lovers who participate are Nature Biology and Environmental Studies ( Biopalas ) located in Medan , North Sumatra.
