The BBC Studios Natural History Unit (NHU) is a department of BBC Studios that produces television, radio and online content with a natural history or wildlife theme. It is best known for its highly regarded nature documentaries, including The Blue Planet and Planet Earth, and has a long association with David Attenborough's authored documentaries, starting with 1979's Life on Earth. The Natural History Unit is a specialist department within BBC Studios Productions. Each year it produces around 100 hours of television and 50 hours of radio programmes, making it the largest wildlife documentary production house in the world. The BBC commissions programmes from the Unit for broadcast on five terrestrial television channels (BBC One, BBC Two, BBC Four, CBBC and CBeebies) and BBC Radio 4. It also makes programmes for other broadcasters and services including Apple TV+, Warner Bros. Discovery, National Geographic Global Networks and NBC Universal. Content is marketed internationally under the BBC Earth brand. Original content is also broadcast on the Earth Unplugged YouTube channel. The Unit has been based in Broadcasting House, Bristol since its formation in 1957, and has been headed by Julian Hector since 2016. History First steps in natural history broadcasting The BBC natural history unit's links to Bristol date back to the 1940s, when Desmond Hawkins, then a young producer, joined the West Region staff. His personal interest in the subject led to a radio series called The Naturalist, which began on the Home Service in 1946 and proved an immediate success, later augmented by Out of Doors and Birds in Britain. By the early 1950s, Hawkins had been promoted to Head of Programmes, West Region and was keen to translate his success to the developing medium of television. At the time, radio still commanded much higher audiences than the fledgling television service, but Hawkins was not alone in recognising the potential for natural history programmes for the newer medium. His vision was shared by Frank Gillard, the regional Head, and the two men would become the driving force behind the establishment of the Natural History Unit (NHU) in Bristol. Until such formalities were completed, natural history programmes were the responsibility of the Features office of the West Region. One of the first programmes was an outside broadcast from the Wildfowl and Wetlands Trust's centre at Slimbridge in 1953, the first TV collaboration between the BBC and Peter Scott. Occasional programmes continued the