 All populations of greater crested tern disperse after breeding . When Southern African birds leave colonies in Namibia and Western Cape Province , most adults move east to the Indian Ocean coastline of South Africa . Many young birds also travel east , sometimes more than 2 @,@ 000 km ( 1 @,@ 200 mi ) , but others move northwards along the western coast . T. b. <unk> winters on the east African coast north to Kenya and Somalia and may move as far south as Durban . Populations of T. b. velox breeding from the Persian Gulf eastwards appear to be sedentary or dispersive rather than truly migratory , but those breeding in the Red Sea winter south along the east African coast to Kenya . T. b. cristata mostly stays within 400 km ( 250 mi ) of its colonies , but some birds wander up to around 1 @,@ 000 km ( 620 mi ) . This species has occurred as a vagrant to Hawaii , New Zealand , North Korea , Jordan , and Israel . 
