“The seasonal movement of billions of sardines along the coast of South Africa, the greatest fish migration on the planet…” Billions. In this clip from PBS’ The Gathering Swarms, synchronous sardines are a constantly-moving shimmer of instinct as predators relentlessly attack from sea and air.

We love sardine run videos and all kinds of swarms. In the archives: EarthTouchTV’s incredible footage of this food chain wonder and the thresher shark’s deadly tail.

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