A shimmer of silver under the surface and we’re off. Moving as one, millions of sardines make their way up the coast in seething masses known to be over 7 kilometres in length and 30 metres deep. You might be thinking ‘sardines? Really? But this really is one of the earth’s most magnificent wildlife feats, a truly spectacular sight that few will ever see with their own eyes.
Tens of thousands of birds, from cormorants and terns to gulls, dive-bomb the twisting mass, in an unrelenting aerial assault, whilst myriad predators attack from below. Bottlenose and common dolphins work together in a sheepdog fashion, forcing thousands of fish at a time into ‘bait balls’, forcing them closer to the surface where they can pounce on their fully suspecting lunch. Shark species, including great whites, hammerheads and bronze whalers attack from below, gulping down the tasty fish that have learned safety in numbers has its limits in the marine world. This almost unlimited sardine supply is also under threat from Cape fur seals, humpback whales and minke whales, as well as shoals of game fish, including Garrick and geelbak.
This magnificent feeding frenzy is a little known phenomenon that can be enjoyed by anyone. Head out in biplanes and watch from the air, stand on the coast and witness the thousands of birds attacking the shimmery mass, or even dive and snorkel for some real adrenaline pumping action (options for beginners and advanced levels of diving and snorkelling).
Why?
This fantastic wildlife ‘migration’ is actually still relatively mysterious, although there are, of course, theories. The most likely is the temperature change. Being in the southern hemisphere, June and July are winter months, and heading somewhat closer to the equator for a bit more warmth seems highly likely. In fact it looks like the sardines don’t bother to migrate unless the water drops below 21 degrees. The breeding season for these sardines is spring to early summer, when they spawn off the Southern Cape Coast. Their eggs are released into the water and fertilised before being left to drift into the wide open ocean, where they are mainly carried north and west by the currents.