Was the sacrifice of an entire generation worldwide an avoidable or a necessary tragedy? Are the roots of World War II to be found in the devastation of World War I? Drawing from over 300 hours of archival footage and tracing the journeys of the civilians and soldiers across the world, anonymous or well-known, who fought for survival in this unprecedented period in human history, both heroic and barbaric. On June 28th, 1914, the assassination of an obscure Austrian archduke in Sarajevo triggers the most disastrous conflict the world has ever known. Germany becomes an enemy to France, invades Belgium, and in September arrives at the gates of Paris.

The first episode looks at how birds first took to the skies in the wake of the insects. It begins in Mexico, where Sir Attenborough observes bats being outmanoeuvred by a red-tailed hawk. Pterosaurs were the birds' forerunners, some 150 million years after dragonflies developed the means of flight, but eventually went extinct together with the dinosaurs. Birds had by then already evolved from early forms like archaeopteryx, the first creature to possess feathers. Its ancestry can be traced through reptiles, and some current species, such as the flying lizard, possibly show paths this evolution may have taken." One of the biggest birds to have ever existed was the terror bird, which proliferated after dinosaurs vanished and stood up to 2.5 metres tall. By comparison, the ostrich, while not closely related, is the largest and heaviest living bird. It was probably the evasion of predators that drove most birds into the air, so their flightless cousins evolved because they had few enemies. Accordingly, such species are more likely to be found on islands, and Sir Attenborough visits New Zealand to observe its great variety, most especially the kiwi. Also depicted is the moa, another huge creature that is now gone. The takahē is extremely rare, and high in the mountains of New Zealand, Sir Attenborough discovers one from a population of only 40 pairs. Finally, another example on the brink of extinction is the kakapo, which at one point numbered only 61 individuals. A male is heard calling — an immensely amplified deep note that can be heard at great distances from its nest.

Born in Groot-Zundert, The Netherlands, Van Gogh spent his early life as an art dealer, teacher and preacher in England, Holland and Belgium. His period as an artist began in 1881 when he chose to study art in Brussels, starting with watercolours and moving quickly on to oils. The French countryside was a major influence on his life and his early work was dominated by sombre, earthy colours depicting peasant workers, the most famous of which is The Potato Eaters, 1885. It was during Van Gogh's studies in Paris (1886-8) that he developed the individual style of brushwork and use of colour that made his name. In 1888 he moved to Arles where the Provençal landscape provided his best-known subject matter. However, it also marked the start of his mental crisis following an argument with his contemporary Paul Gauguin. Van Gogh was committed to a mental asylum in 1889 where he continued to paint, but he committed suicide in 1890.

Take another walk on the wild side with our favourite pets. Extraordinary photography reveals their hidden senses and secret communication skills. Dogs take a car trip through Paris, using their legendary sense of smell to show us a very different city. A hamster uses his remarkable senses to stage a great escape and then deploys more navigational talents to find his way home. Cats become intoxicated on the scent of a plant and suffer the consequences. A budgie shows his hidden charms to his mate as, under UV light, his crown and cheeks positively glow. Goldfish reveal secret senses that can detect the slightest water movement. A guinea pig gives birth and the newborns receive surprising care from their father. In South America, where guinea pigs have lived with people for 7,000 years, they express the true meaning of their entertaining calls. When we groom a horse we speak their language, but horses use ears to communicate in ways that we are rarely aware of. In Japan cats show their secret messages and in Peru dogs reveal the hidden signs that allow them to communicate across a city. Packed with extraordinary facts and wild behaviour - you'll never look at your pet in the same way again