The producers of Planet Earth II have defended the programme against accusations its scenes are too brutal, saying they must compete with television rivals like Game of Thrones.

The programme, hosted by Sir David Attenborough, has been criticised by horrified viewers for what some called a "rape" scene between copulating snow leopards, as well as high-jeopardy snake chases.

But producers have said they must give modern viewers an "emotional journey" during their natural history show as they square up against blockbusters dramas for attention.