While overshadowed by the other David – and out of step on both the EU and climate change – the naturalist and presenter will be remembered for his unbridled enthusiasm for botany

The jolly, bearded, accessibly scholarly botanist David Bellamy, who has died aged 86, was for many years one of TV’s most effective popularisers of science. That was, until his career stalled when he found himself on the wrong side of the political and environmental climates.

There has always been a tension in British television between the founding aims of the nation’s broadcasting, expressed in the BBC charter – “to inform, educate, and entertain” – with the first two often struggling to compete with the third. One solution to this conflict was the expert who was also eccentric. Between the 1960s and the 1980s, Bellamy was a member of this group of wacky specialists, along with futurologist James Burke, dog psychologist Barbara Woodhouse, and scientists Dr Magnus Pyke and Professor Heinz Wolff, with the last of whom Bellamy appeared in the high-rating ITV scientific brains’ trust formats, Don’t Ask Me (1974-78) and Don’t Just Sit There (1979-80).

Looking and sounding outside the norm for authoritative broadcasters, they could all have retired early if they had been paid royalties by the TV impressionists who gleefully imitated them. The beard alone required a long stint in the makeup chair for Mike Yarwood or Lenny Henry, or anyone else wanting to take Bellamy off. As his signature facial hair thickened and whitened, he could have walked onto stage as God, Captain Birdseye or Santa Claus without cosmetic preparation.

Facebook Twitter Pinterest Bellamy in his 1978 series Botanic Man. Photograph: Fremantle Media/REX/Shutterstock

His avuncular appearance and manner made Bellamy popular with younger viewers, bringing him regular guest slots on children’s shows such as Blue Peter and Multi-Coloured Swap Shop, and leading schedulers to trust him in the family-friendly early evening slots.

His TV career was relatively brief, occupying less than a third of his life, mainly compressed into a quarter-century between 1970, when he presented the series Life in Our Sea, and 1996, which saw Upstream With Bellamy, the culmination of a run of knowledgeably enthusiastic travelogues that had also included Bellamy’s Britain, Bellamy’s Backyard Safari, and Bellamy’s Seaside Safari.

Although he largely featured in peak-time populist formats, Bellamy had first come to the attention of broadcasters as an expert commentator on news and current affairs programmes. Employed in the Botany department of Durham University since 1960, he conducted an influential study of the impact of the 1967 environmental disaster, when the SS Torrey Canyon supertanker spilled upwards of 25 million gallons of crude oil into the sea off the South-West English coast. Impressing as a TV “talking head” on that story, Bellamy was identified by producers of light factual shows as a potential star.

As a televisual elucidator of the natural world, Bellamy was inevitably compared - in most cases, to his disadvantage - with his first-name-sake, David Attenborough, often fielded as an attempted ITV rival to the broadcaster who was for a long time synonymous with the BBC.

At least one comedy sketch show spoofed the presenters as The Two Davids, in the fashion of The Two Ronnies. The joke was helped by the fact that, like the large Barker and the small Corbett, the two TV naturalists were markedly contrasting. Attenborough was posh, skinny, mellifluously whispering; Bellamy Cockney-ish, burly, lispingly loud.

It was a consequence of Bellamy’s rougher appearance and speech that, although he was by some distance more academically qualified in his discipline than Attenborough was in his, the other David tended to be seen as the more serious and informed reporter.

Facebook Twitter Pinterest Bellamy alongside Lenny Henry in Tiswas Reunited in 2007. Photograph: ITV/REX/Shutterstock

Their contrasting destinies in television – Attenborough probably the second most famous Briton after the Queen, Bellamy unknown to younger generations - were influenced by the public positions they took. In 1997, Bellamy stood against the then-Prime Minister John Major in the Huntingdon constituency, running for the Referendum Party, a precursor of UKIP. He finished fourth with 3,114 votes, just shy of a tenth of those gained by the victorious Major, showing again that, in Britain, it is easier for politicians to become celebrities than the other way round.

History proved Bellamy to have been an early adopter of the topic that would come to dominate UK democracy - that is, of course, Britain’s place in the European Union - but his public partisanship breached broadcasting codes, and his screen-time visibly reduced.

Bellamy then sealed his exile by becoming vocal about another issue beginning to energise right-wingers: climate change. Despite, after the Torrey Canyon incident, being one of the first voices to denounce humankind’s casual attitude to the planet, Bellamy later turned against the scientific consensus of an impending planetary emergency, declaring such concern to be “poppycock”. Opposed to much of the country – and almost all of the broadcasting establishment – in his political and scientific positions, Bellamy’s role as a presenter of major documentaries now appeared untenable.

The decline was shown by the fact that his last book was published in 2005, and his final TV appearance was in 2009, the consequences of the choices he had made underlined by the continuing busyness of Attenborough during that period. In comparison with the adaptable perennial who continues to dominate natural history programming, TV’s most popular botanist only enjoyed a brief flowering.