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GREAT WHITE - THE PREDATOR |
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Predatory events are usually first detected at the surface by one or more of the following indicators;
Incoming seals abruptly changing course,
Seals suddenly switching from porpoising to rapid zig-zag leaping,
A group of travelling seals suddenly exploding from the water in multiple directions,
A Great White Shark breaching, with or without a seal in its mouth,
A bloody splash, often accompanied by a spreading oily slick, or
Kelp Gulls or other seabirds wheeling over or plunging repeatedly toward a discrete region of sea surface.
Cape Fur Seals apparently reduce their vulnerability to Great White Sharks by:
taking advantage of the expanded vigilance of entire groups; sub-surface vigilance while rafting is accomplished via assuming a head-down posture, with only the tail and the tip of the rear flippers showing above the surface.
leaving islands as part of groups of 8 to 12 animals; multiple groups – ranging from 2 to as many as 5 - leave the island at intervals of approximately 45 seconds
single or small groups (2-5) of individuals executing a finely controlled zig-zaging evasive manoeuver when a Great White Shark is spotted stalking below them; this tactic is referred to as “working the shark”
when an individual is actively pursued by a Great White Shark, riding its slipstream – usually mid-body, at the level of its dorsal fin – to remain out of reach of the shark’s jaws; this tactic is referred to as “on the shark”
when a group is “hit” (attacked) by a White Shark, the individual seals ‘explode’ from the water in all directions, presumably serving to confuse the predator – perhaps sufficiently to allow some or all of them to escape; this tactic is relatively infrequent but highly spectacular
when an individual or group returns to the island, swimming the last 50 metes or so underwater, presumably because this tactic reduces vulnerability to attack by White Sharks
when any or all of the aforementioned tactics fail and a predatory attack is successful, the surviving seals become extremely vigilant - often to the point of seeming momentarily stunned - but are, in fact, hyper-alert
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