Sir David Attenborough has said the BBC’s natural history programmes have helped “world opinion change” about conservation, as his latest series, Mammals, highlights the damage “overcrowded” game reserve tourism has on cheetahs – which he says we are in danger of “loving to death”. In the same way Blue Planet II raised awareness of plastics, the six-part BBC One programme is likely to prompt questions about safari holidays through footage of large numbers of tourist-filled trucks chasing views of hunting cheetahs making a kill – which can often result in the animals leaving the meat and cubs dying. Mammals, which comes 22 years after Attenborough’s acclaimed Life of Mammals, has the broadcaster explain: “With an estimated 69mn visitors to protected sites in Africa each year” parts of it are “becoming overcrowded”. As a hunting cheetah is chased by vehicles “there is pressure to get the best view of the kill. As the predators start to hunt, so do the cars,” Attenborough explains. With more than 70 trucks encircling the cheetah after it has caught its prey, Attenborough warns: “Wildlife experts studying the cheetah recommend that there should be no more than five vehicles to each sighting.” He says tourism is essential to fund protection of the animals and the reserves they live in but “we are in danger of loving these cheetah to death” because the huge number of vehicles “comes at a cost” as “more of the cheetah’s hunts fail and more of their kills are abandoned”. Attenborough adds: “In areas of high tourism, research has shown that the survival of cubs is also greatly reduced. It must surely be possible to respect the animals’ need for space and at the same time enable human visitors to have a meaningful glimpse of the wild world. That is what must be achieved if cheetah are to have a future on the African plains.” At a screening of the BBC Studios show in London, Roger Webb, the series’ executive producer, said “hopefully it starts conversations”, while the series producer Scott Alexander said the BBC was “not pointing fingers … just pointing out realities”. Attenborough added how powerful an effect the BBC’s shows could have, saying he had seen “world opinion change as a consequence of the [BBC Studios’] natural history unit (NHU) … nobody else can hold a candle to it … it’s had a worldwide effect.” He said the unit, which is cutting up to 7% of its roles due to a TV market slowdown, was “something the BBC can be very, very proud of. The NHU is an extraordinary worldwide organisation which has no parallel anywhere else.” Attenborough also defended the BBC licence fee, as although the NHU is part of the corporation’s commercial wing BBC Studios, it was set up with public money and there is “a benefit” of “a public service backed by the nation”. He said his favourite sequences were rare footage of the desert-dwelling fennec fox, which “I never thought I’d see”, although tragically the producers discovered two they were filming had been killed for fun by humans. Attenborough also highlighted a “breathtaking” sequence of big cats hunting monkeys in treetops at night – made possible, said Webb, thanks to “a man in a shed in Norfolk” adapting a night-time camera. Other new technology used included a large “underwater drone” called The Beast, developed by more “men in sheds”. The producer, Daniel Rasmussen, said it allowed the BBC to film “behaviours we’ve never managed to capture before”, including orcas hunting humpback whales. Mammals, filmed over five years, also features never-before-seen footage of wolves living among landmines in the Golan Heights to escape humans, the scientific discovery that echidnas chat to each other using “endearing” noises and a touching sequence involving Etruscan shrews. Webb described how much filming had changed since Life of Mammals, with this series using an “unfiltered” approach, with less music and more natural sound to immerse viewers in the creatures’ worlds. Mammals begins on Sunday 31 March on BBC1.