Thousands of people have taken to the streets of central London to protest against the start of Britain’s grouse shooting season.

Animal rights supporters are campaigning to end the sport, which would be their biggest breakthrough since MPs voted to ban fox hunting in 2004.

Moorland estates across Scotland and northern England opened the annual red grouse-shooting season on Saturday, known as the Glorious Twelfth, the day after a wildlife expert said grouse moors were to blame for persecuting endangered birds of prey in the Scottish Highlands and Uplands.

Other animal rights events on Saturday included a protest ramble on Ilkley Moor where opponents of the last shoot taking place on public land believe they are on the cusp of victory.

Speakers at the London event, including the BBC presenter Chris Packham, said the days of the West Yorkshire shoot were numbered as Bradford faces unprecedented pressure not to review the lease next year.

“I think that when people now see others killing for the psychopathic joy of it they are increasingly sickened and the reason for that is that our wildlife is running out,” Packham said.

He claimed public support for conservation in the UK had risen on the back of global outrage over the 2015 killing of Cecil the lion in South Africa and increasing use of social media.

“It means that on Thursday, for example, the RSPB published video of marsh harriers being killed on a grouse moor in Yorkshire and within hours of that material going on to YouTube it has been spread all around. Everyone is instantaneously angered as it gets shared and there is frankly nowhere for these criminals to hide.”

Clad in papier maché fox heads and carrying banners for causes ranging from the campaign against badger culling to maintaining the fox hunting ban, marchers walked down Oxford Street to Whitehall.



Danielle Flynn, 55, a former hunt saboteur from Glasgow, was marching with her daughter Karen, 24, who said: “I think social media has been a big thing among my generation. A lot of them might be apathetic about politics but they might, for example, take an interest when I talk to them about animal testing and makeup.



“I also tend not to like conflict and you have to be careful what you say to people these days, so the thing about a Facebook post or a YouTube video is that you can get your message across to people without having to confront them.”



Jordan Psaros, 26, from Braintree, in Essex, said she had been considering voting for the Conservatives at the general election but had decided not to after learning of Theresa’s May’s support for a free vote on overturning the fox hunting ban.



“I’ve always been an animal lover but I basically became involved in this after I saw some videos online of foxes being killed by dogs set on them by hunters on horseback,” she said. “I think that a lot of people of my age are waking up to what is going on.”

Animal rights supporters have been emboldened by the public reaction to recent controversies, including an outcry that forced the Arsenal football club owner Stan Kroenke to order his TV streaming service to stop showing big-game hunting, and the row over a photograph of 100 dead foxes that appeared on Vinnie Jones’s Twitter feed.



May’s support for a free vote on overturning the hunting ban led some Tories to complain that it contributed to “toxifying” the party brand during the election. The focus group consultancy Britain Thinks found that while the “dementia tax” was key among older voters, fox hunting had an impact on swing voters, alienating many.

Pro-hunting advocates have said it is impossible to say whether the animal rights movement is resurgent in terms of actual numbers, and that data suggests the public do not change their vote on the basis of hunting or shooting issues. They said a YouGov poll in May, which showed support for the ban at 67%, suggested an actual decline in support.

A dog retrieves a shot grouse on Lofthouse Moor in North Yorkshire. Photograph: Danny Lawson/PA

“If there has been any genuine resurgence of animal rights activism, it can almost certainly be attributed to social media,” said Liam Stokes, head of shooting at the Countryside Alliance.

“Animal rights messages are very simplistic, and simplistic messages spread well on Twitter and Facebook, particularly when broadcast by celebrities like Packham and Brian May. The arguments for wildlife management are complex, nuanced and sometimes paradoxical, and don’t lend themselves so easily to social media.”