The second programme shows how life along the Amazon River is dominated by the annual cycle of floods. In the dry season, female giant river turtles gather on exposed sand banks to lay their eggs. As broad reaches of river are cut off by sandbars, caimans and egrets take advantage of the bounty of fish trapped in shallow lagoons. Underwater infrared cameras film scavenging candiru and an electric eel hunting.

• Fergal Keane