It's spring on the desolate Falkland Islands, which is suddenly crowded with animals converging to breed and raise their young over the short summer.

Each year, the seemingly delicate monarch butterflies undertake a multi-generational migration from Mexico all the way to Canada and back again.

Tracing ancient paths, wildebeests become a moving feast. But the biggest threat is the gauntlet, the saltwater crocodile filled Mara River crossing.