This year marks 20 years since the first Cornish-born choughs were seen once again out on the cliffs, after numbers fell to zero in 1973.

The Cornish Chough Conservation Network is celebrating the milestone by launching a short film to give recognition and thanks to all who have been involved in getting choughs to where they are today.

The network includes: the RSPB, National Trust, Natural England, Cornwall Bird Watching Preservation Society, volunteers, local farmers, land-owners, and members of the local community. It is a strong example of people coming together to help nature, the network believes.

Return of the Chough was made by local film-maker Lewis Jefferies.

As well as celebrating this success, the film aims to encourage more people to continue the work of conservation and report their sightings.

Choughs were once a common feature along Cornish clifftops.

However, persecution by trophy-hunters and changes to agriculture, leading to a loss of chough homes, meant that “by 1973 the choughs’ wonderful calls could be heard no more across the cliff tops”, said Edward Rowe, Cornish actor, and narrator of the new film.

For the next 28 years, choughs remained absent from Cornwall; the only recorded sightings being of a few birds passing through. The natural return of choughs to Cornwall in 2001 changed all that.

Cat Lee, National Trust volunteering and community manager, said: “There was excitement, but there was also tension because you’ve only got two breeding pairs, and everything is hanging on those pairs to grow that population.

“So, we monitored those birds around the clock when they had eggs. The main thing I remember is the enthusiasm everyone had, volunteers came from across Cornwall to look after these special birds.

“The return of the chough has been no small feat. Only through great partnership work, and the support of a team of dedicated volunteers has this been possible and it is testament to the hard work of nature-friendly farmers and land-owners for providing the suitable landscape that choughs need to survive and thrive.”

Phil Taylor, of Cornwall Bird Watching Preservation Society, said: “The chough population now is doing very well.

“The last three breeding seasons have been exceptionally good and each one improving on the last.”

This year 25 pairs of Cornish choughs successfully raised more than 70 young, bringing the population to over 200 birds, sighted around the coast of Cornwall and now even sections of the mid and north coast.

Jenny Parker, RSPB Cornwall reserves site manager, said: “The partnership’s focus over the coming year will be monitoring the chough population, improving and extending their habitat, getting more farmers involved, and making sure funding is available to put the right habitat management into practise.”

Hilary Mitchell, of Cornwall Bird Watching Preservation Society, said: “We wouldn’t have had the choughs being as successful as they are without everybody out there who sends their chough sighting emails in - because that helps us find new pairs.

The film can be watched at bit.ly/Chough20Years