Forget the migration of the wildebeest on the plains of the savanna. Forget also the Sardine run and visit the southern African coastline in wintertime where one of the most spectacular as well as long migrations on earth is performed by a majestic giant: the mighty humpback whale…
A humpbackwhale season
From as early as June and July humpback whales (Megaptera novaeangliae) start to appear along the shores of South Africa and Mozambique after travelling thousands of kilometers from Antarctica. These massive on average 12 to 16 meter long mammals have only one goal and that is arriving on their mating and calving grounds as far up north as Kenya. The warmer waters up north lack their natural predators like for example orca. Orca seem to prefer colder water and are seen around False Bay from time to time. Also, the water temperature is a lot more forgiving for a young calf since it has a very low amount of body fat directly after birth compared to more mature whales.
Adult whales do not feed during their migration as well as their stay in the warm waters of the Indian ocean. Feeding is done during summertime in the southern hemisphere when the waters around Antarctica are host to enormous amounts of krill and fish (like herring and mackerel). Some of the whales are observed practicing a cooperative feeding strategy called bubblenet feeding. Small fish are trapped in curtains of rising air released by one of the whales down below. Shortly thereafter whales scoop big amounts of these fish into their wide open mouths while speeding into the ball of fish. After entrapment they use their baleens to filter the fish from the seawater trapped inside. In doing so the humpback whales build up enough fat reserves for their next long migration in wintertime.