Nature documentaries as we knew them changed forever with Planet Earth in 2006. Anchored by the celebrated broadcaster and naturalist David Attenborough, the BBC show offered new perspectives on wildlife, delivered in visually stunning high-definition. The show has returned for a second season, and has landed with a bang.

The November 6 opening episode, which was screened on BBC One in the United Kingdom, is set on various island habitats and features a three-toed pygmy sloth, Komodo dragons, lemurs and penguins. The highlight: a never-before-seen battle between baby iguanas and a swarm of racer snakes on the Galapagos island of Fernandina, including an incredibly tense standoff between prey and predator. Viewers have actually been spared a lot of horrific footage, according to producer Elizabeth White. She revealed in an interview that some of the snakes were actually devouring each other.

Planet Earth II is being shown at a time when concerns over the state of the environment are at their peak. When asked about his take on the issue, Attenborough was optimistic. “The problem we have got now is much more widespread and more deeply seated than the ozone problem was, and it’s got worse because of the growing population,” he said in an interview. “But we got together then, and I believe we are on the verge of getting together now. It isn’t as though we don’t understand what the problem is, or we don’t have the ways of solving it. We do.”

Plenty of warnings have been issued and scores of articles have been written about the threats to animal species from poaching, deforestation, climate change and expanding human habitats. Another powerful scene from the episode is of millions of crabs being interrupted by acid-spewing ants on their march to the sea. “Humans brought these ant invaders here and now humans are having to control them,” Attenborough says. “Of all the species that have become extinct in recent years, around 80 per cent have been islanders.”