Reconstructing a dinosaur skeleton for a museum is a balance between art and science - but getting that balance right is a tricky diplomatic, as well as scientific, process. Presenter and anatomist Dr. Alice Roberts follows the reconstruction of L.A.'s Natural History Museum's 2011 dinosaur exhibit.
This programme focuses on birds. The feather is key to everything that is crucial about a bird: it is both its aerofoil and its insulator. The earliest feathers were found on a fossilised Archaeopteryx skeleton in Bavaria. However, it had claws on its wings and there is only one species alive today that does so: the hoatzin, whose chicks possess them for about a week or so. Nevertheless, it serves to illustrate the probable movement of its ancestor. It may have taken to the trees to avoid predators, and over time, its bony, reptilian tail was replaced by feathers and its heavy jaw evolved into a keratin beak.
We reveal the weird and wonderful stories of some of the natural world's incredible single parents: their devotion, dedication and often jaw-dropping endeavour in order to see their babies through to adulthood. From the slow loris covering her baby in toxic saliva to the Weddell seal putting her pup through winter boot camp, a weedy sea dragon cleverly camouflaging his eggs against his body and the female giant Pacific octopus sacrificing herself for her brood - we see how these parents are prepared to go the extra mile to arm the next generation with what they need to survive.
Bill Turnbull investigates one of the biggest mysteries in the British countryside: what is killing our bees. It is a question that generates huge controversy. Changes in the weather, pesticides and even a deadly virus have all all been blamed. It is a question that Bill is all too familiar with as a beekeeper himself. He meets the scientists who are fitting minute radar transponders on to bees to try to find answers.
While most of the series has focused on conflict, this episode is all about co-operation. The suitably named social spiders spin one enormous, 30m web for the whole colony, a queen bee rules her hive with a strict hierarchy and some green ants show great team spirit to help build a nest together. There are no broken societies here. David Attenborough shifts the focus to bugs that prefer cooperation rather than conflict. They include burrowing cockroaches, the suitably named social spiders - which share a 30-metre web.