David Attenborough returns to the island of Madagascar on a very personal quest. In 1960, he visited the island to film one of his first ever wildlife series - Zoo Quest. Whilst he was there, he acquired a giant egg belonging to an extinct bird known as the 'elephant bird' - the largest bird that ever lived. It has been one of his most treasured possessions ever since. Fifty years older, he now returns to the island to find out more about this amazing creature and to see how the island has changed. Could the elephant bird's fate provide lessons that may help protect Madagascar's remaining wildlife? Using Zoo Quest archive and specially shot location footage, this film follows David as he revisits scenes from his youth and meets people at the front line of wildlife protection. On his return, scientists at Oxford University are able to reveal for the first time how old David's egg actually is, and what that might tell us about the legendary elephant bird.

David Attenborough tells the story of the discovery and reconstruction in Argentina of the world's largest-known dinosaur, a brand new species of titanosaur. Measuring 37m long - close to four London buses put end to end - and weighing 70 metric tons, it now holds the record as the biggest animal ever to walk the earth. In 2014, a shepherd spotted the tip of a gigantic fossil bone sticking out of a rock in La Flecha Farm in the Chubut Province in the Argentinian desert. Palaeontologists soon uncovered a massive 2.4m long thigh bone (femur), the largest ever found. By the end of the dig they had uncovered more than 220 bones. As the programme reveals, these all belong to a new species of the giant plant-eating titanosaur. Filmed over the next two years, the documentary follows the twists and turns of this forensic investigation. Attenborough witnesses the uncovering and examination of these stupendous fossils and the dramatic construction of the complete skeleton. And using state-of-the-art graphics, the film also reveals the internal secrets of this dinosaur and what it means to be a giant.

David Attenborough investigates the remarkable life and death of Jumbo the elephant - an animal superstar whose story is said to have inspired the movie Dumbo. Attenborough joins a team of scientists and conservationists to unravel the complex and mysterious story of this large African elephant - believed by many to be the biggest in the world. With unique access to Jumbo's skeleton at the American Museum of Natural History, the team work together to separate myth from reality. How big was Jumbo really? How was he treated in captivity? And how did he die? Jumbo's bones may offer vital clues. Arriving in London Zoo in 1865, Jumbo fast became a firm favourite of Queen Victoria and her children, and was nicknamed the Children's Pet. Yet behind the scenes, this gentle giant was living a double life - smashing his den, breaking his tusks and being pacified by large amounts of alcohol given to him by his keeper, Matthew Scott. Scott had no human friends but had a deep empathy for animals, developing a particularly strong and near mystical bond with Jumbo. Then, quite suddenly, London Zoo caused public outrage by selling Jumbo to PT Barnum's circus in America, where he travelled with his devoted keeper to start a new life. But while his time in America turned him into star with 20 million people coming to see him, his life ended tragically and mysteriously. As well as Jumbo's skeleton, Attenborough explores the lives of wild elephants to explain Jumbo's troubled mind, and he discovers how our attitude to captive elephants has changed dramatically in recent years.