Leonora is no ordinary orangutan, she is a pioneer. With her three year old son in her arms, she is about to set off on an epic journey back to the wild - the great ape escape. It is a long way from what she is used to. After being orphaned as a baby, she has spent the majority of her life in a rescue centre. She is leaving behind 600 other orangutans, all of whom are relying on her for their chance at freedom. If Leonora can make it, they could too.

Leopards are built for strength rather than speed, hunting in the shadows and ambushing their prey. In an ever shrinking world, their lives are colliding with people - attacks are reported regularly and hundreds of these big cats are stoned, trapped or shot.

Sri Lanka, the tropical island lying off the southern coast of India, is home to its own special elephants. A sub species of the Asian elephant, they have their own unique characteristics. In this programme, award winning wildlife cameraman Martyn Colbeck of Echo of the Elephants fame travels to Sri Lanka to try and get to know them. Martyn has planned his arrival to coincide with the start of the monsoon, hoping it will be the best time to find and follow a new born calf. By drawing on local knowledge, Martyn begins to unravel the complex social world of Sri Lanka's elephants - he witnesses a fight over a calf, a battle between two bulls in musk and, at an elephant sanctuary, befriends an orphaned elephant who sadly lost a leg to a snare and is facing an uncertain future.

Vultures are the birds that many people love to hate, but cameraman and naturalist Charlie Hamilton James sees them as beautiful and intelligent creatures that deserve respect. He believes that to appreciate them, people just need to spend time with them and he headed to East Africa to do exactly that. His journey exposes not only a softer, more caring side to these maligned birds but also a much bigger story, one that leaves vultures needing many more admirers.

The giant squid, a creature of legend and myth which even in the 21st century, has never been seen alive. But now, an international team of scientists think they have finally found their lair, one thousand metres down, off the coast of Japan. This is the culmination of decades of research. The team deploys underwater robots and state of the art submersible vessels for a world first - to find and film the impossible.

Peanut, Hero and Tarzan are three cheeky monkeys. They live on the paradise Indonesian island of Sulawesi with the rest of their gang of crested black macaques. These very special primates are found nowhere else in the world. Twenty-five years ago, wildlife cameraman Colin Stafford-Johnson visited Sulawesi for the first time and now he's returned. Fascinated by the monkeys, Colin hopes to reveal their sometimes violent, often playful and, just like our own, highly political world. What he discovers leads him on a much bigger journey than he was ever expecting.

Meerkat pups Squirt and Weeny belong to one of the most famous animal families on the planet, animals that are now stars of screens both big and small. These furry celebrities are also part of the longest running animal behaviour study ever, now in its 20th anniversary year. David Attenborough tells the full story of the study - from its pioneering days when it was a challenge to even get close to a meerkat, to the very latest revelations about these animals and their complex lives. For Squirt and Weeny, the study means very little, as they are facing up to the challenge of a drought and one of the toughest years in their family's history.

David Attenborough narrates the charming and fascinating story of some real-life animal romantics. There are show-offs and singers, dancers and fighters, stories of undercover affairs and heart-warming devotion. These include a male polar bear that plays hard to get, a lemur whose odour bags him a mate and a lizard who is tender and faithful to the very end. It reveals that animals can be loving, complex, funny and inventive - it is all part of the mating game.

Sivuqaq is an 18 year old, larger than life captive pacific walrus. By now he should be a dad but things have not worked out. This is where reproduction scientist Holley Muraco comes in. Holley is taking on the biggest challenge of her career - trying to help Sivuqaq become a parent. Yet walrus love is a mystery - even pandas have been bred more successfully than walruses. Holley hopes the clues lie in in exploring the lives of Sivuqaq's wild cousins and that she can find the answers by journeying to their breeding grounds in Northern Alaska.

The killer whale was long feared as a sea monster until, in May 1964, one was brought into captivity for the first time. This spawned a journey of discovery into the killer whale's true nature. It quickly became clear, these were not mindless killers - they were, in fact, highly intelligent social creatures. Today, our understanding is deepening still further and the latest revelations are among the most sensational - not only will these top predators 'adopt' and care for injured and abandoned orphans, but it seems there's no longer just the 'killer whale'.