TV naturalist Chris Packham has led a protest against the illegal killing of a rare bird of prey.
Hundreds of campaigners at seven sites across the country took part in Hen Harrier Day, which aimed to raise awareness of the targeting of the birds.
They are protected by law but conservationists say they are shot because they prey on red grouse, with the protests timed to coincide with the start of grouse shooting season on Wednesday.
Springwatch presenter Packham was at the protest in the Peak District, Derbyshire, and said cases like Cecil the Lion show the how strong the public feel about preserving wildlife.
He said: "People are tired of animal life being wasted and particularly when that life is becoming increasingly rare.
"Killing hen harriers is illegal. We are not here to voice our opinion, we are here to ask for the law of the land to be upheld so that this persecution stops."
He added that of the 350 to 400 pairs of hen harriers expected to be found nesting in the country last year, there were only six pairs found.
Packham said: "There's a real danger that some of the children who have come along today won't get the chance to see a hen harrier in their lifetime.
"The type of shooting practised here developed in Edwardian times and they still want to do that.
"We're not living in Edwardian times and our wildlife populations can't take that sort of attrition any longer.
"But it's more than just about hen harriers, it's about the mistreatment of this habitat and more broadly about issues where there's poor governance when it comes to handling and management of our natural environment.
"The hen harrier has become a totemic symbol for this."
A petition banning the shooting of grouse, which campaigners say leads to the illegal killing of hen harriers, has reached more than 11,000 signatures.
But organisations which back grouse shooting say research shows managing the land for grouse shooting is good for wildlife, boosting the breeding of birds including curlew, lapwing, golden plover and redshank.
They also say it boosts jobs, services and businesses in often remote rural areas.
But leading conservationist Dr Mark Avery, who set up the petition to ban grouse shooting, said: "They call it the Glorious 12th when the grouse shooting season starts but they should be calling it the inglorious 12th.
"Hen harriers have been protected in law for more than 60 years and yet they keep on disappearing. This is just a gathering of ordinary people who think it's wrong and want our hen harriers back."