The tropical Indian Ocean is home to the Spice Islands. Characterised by beautiful sandy beaches, fringing coral reefs and coastal mangrove forests, this is a vibrant nursery area for marine life, such as whale sharks, crabs, seahorses and a great variety of fish. The coastal areas are where humans have the most direct impact on the ocean's resources.

The next instalment focuses on dietary needs and how different species have evolved beaks to suit their individual requirements. The latter come in a multitude of forms. Blue tits and goldfinches have beaks akin to tweezers, with which to extract seeds, while the hawfinch's razor-like bill can deal with a cherry-stone. However, the crossbill is the only finch that can twist its mandibles in opposite directions. Jays store acorns for winter by burying them in the ground, whereas woodpeckers can keep up to 60,000 of them in one tree trunk. Sap is also desirable, and there are a variety of methods used to obtain it. The hoatzin is the only specialised leaf-eater, and accordingly has a digestive system more akin to that of cattle. Plants recruit birds to aid pollination, and offer nectar as a reward. Hummingbirds eat little else, and the sword-bill's beak is the longest of any bird in relation to its body. Insects are also highly prized, and Galapagos finches are shown to possess some ingenuity as they not only strip bark, but also use 'tools' to reach their prey. Crows are hailed as being among the most intelligent birds, and one is shown using a twig to spear a grub within a fallen log. The robin is an opportunist, and Sir Attenborough observes one seizing morsels as he digs a patch of earth. In South America, a cattle tyrant sits atop an obliging capybara and uses its vantage point to spot passing food that may be dislodged by its grazing partner.

The film exposes the dark world of ivory trafficking. Ivory is a prized status symbol for middle class Chinese, and poachers in pursuit of elephants in Africa are causing a great damage. Award-winning director Richard Ladkani and Kief Davidson filmed undercover for 16 months infiltrating and documenting the deep-rooted corruption at the heart of the global ivory trafficking crisis.

Jungles cover roughly three per cent of our planet yet contain 50 per cent of the world's species. High-definition cameras enable unprecedented views of animals living on the dark jungle floor. In the Ngogo forest the largest chimpanzee group in the world defends its territory from neighbouring groups. Other jungle specialists include parasitic fungi which infiltrate an insect host, feed on it, and then burst out of its body.

Fifty years ago there were close to half-a-million lions in Africa. Today there are around 20,000. To make matters worse, lions, unlike elephants, which are far more numerous, have virtually no protection under government mandate or through international accords. This is the jumping-off point for a disturbing, well-researched and beautifully made cri de coeur from husband and wife team Dereck and Beverly Joubert, award-winning filmmakers from Botswana who have been Explorers-in-Residence at National Geographic for more than four years. Pointing to poaching as a primary threat while noting the lion's pride of place on the list for eco-tourists-an industry that brings in 200 billion dollars per year worldwide-the Jouberts build a solid case for both the moral duty we have to protect lions (as well as other threatened "big cats," tigers among them) and the economic sense such protection would make. And when one takes into account the fact that big cats are at the very top of the food chain-and that their elimination would wreak havoc on all species below them, causing a complete ecosystem collapse-the need takes on a supreme urgency.

The film is a cinematic quest to find the '52 Hertz Whale,' which scientists believe has spent its entire life in solitude, calling out at a frequency that is different from any other whale. As we search for this elusive creature, we will explore the phenomenon of human reaction to its plight, while revealing its connection to the growing epidemic of loneliness in our interconnected world.