A conservationist from Oxfordshire marched through London unclothed and painted as a bird as part of a campaign to support declining species in the UK.

Hannah Bourne-Taylor made a speech on behalf of the swift population at Speaker's Corner in Hyde Park wearing dark blue, black and white body paint applied by artist Guido Daniele.

The 36-year-old, who moved from Africa to the Oxfordshire countryside, then marched with a group of protesters to Hyde Park Corner, past Buckingham Palace and through Westminster to Downing Street where she read out a letter to Prime Minister Rishi Sunak.

Members of the public could be seen stopping, pointing and taking pictures as she marched through the streets and posed at major London landmarks.

The action comes after her nature memoir, Fledgling, went viral earlier this year following the publication of a newspaper article detailing how she reared a baby bird and let it nest in her hair for 84 days.

Oxford Mail: Hannah Bourne-Taylor outside Downing StreetHannah Bourne-Taylor outside Downing Street (Image: Handout, Press Association)

During her Speaker's Corner speech, Ms Bourne-Taylor announced the launch of a petition as part of her campaign, The Feather Speech, with the support of the Royal Society for Protection of Birds (RSPB) and the charity Rewriting Extinction.

She explained that the petition is calling for "swift bricks" in all new housing developments - bricks with holes that can become nesting environments for four declining UK species - swifts, house sparrows, house martins and starlings.

"I stand here today as a go-between for swifts to ask for your camaraderie because they need your help," she said.

"Together we can stop these remarkable British birds from passing into legend."

Ms Bourne-Taylor went on to speak from the point of view of the swift population as if they could "fight for their existence with words".

"We are screaming for you to help us, to look up to remember you share your home with other kinds," she said.

"Feathers, birds, fins, scales, wings - our shared home is becoming parched with life, destroyed, flooded, licked by flames ablaze.

"Through these shared struggles we only ask for one thing, a safe place to rest after our perilous journey home."

Ms Bourne-Taylor ended by calling The Feather Speech "an alliance with our wild neighbours".

After arriving at Downing Street, the conservationist began to read out a letter to Mr Sunak in which she called on him to "please acknowledge our walls also belong to adventurers".

"I was willing to use my voice for these irreplaceable birds by launching this campaign, unclothed, painted neck to toe because passion is a superpower and every bird counts," she said. "They are running out of time."

"Behind the theatre of this campaign, there is a serious issue of development calling biodiversity loss," she said.

"And these cavity-nesting feathered neighbours are not included biodiversity net gain measures despite all of them facing national distinction because of us."

The group of protesters with her then began to chant: "Every bird counts."

Ahead of the protest on Saturday morning, Ms Bourne-Taylor told the PA news agency that she was protesting in body paint "because I'm a person of no influence so when it comes to the environmental crisis, I feel completely helpless as an everyday person and I suddenly realised that I could change that if I could use visual imagery".

"So the Feather Speech is all about how there are leading scientists and a world-renowned artist coming together for the birds," she said.

Ms Bourne-Taylor said she is aiming for 100,000 people to sign the petition in the next six month so it will be debated in Parliament.

Oxford Mail: Hannah Bourne-Taylor with her skin painted to resemble a bird stands outside the Palace of WestminsterHannah Bourne-Taylor with her skin painted to resemble a bird stands outside the Palace of Westminster (Image: Handout, Press Association)

RSPB executive director Emma Marsh said: "Swifts are one of many species desperately in need of our help.

"More than half have disappeared from UK skies in just 20 years, partly because of a lack of suitable nesting sites.

"As Hannah's amazing campaign highlights, swift bricks should be compulsory in all new housing developments.

"I would urge everyone to sign this petition to help ensure swifts and other species that have traditionally nested in the cavities of our buildings have a safe home to return to every year."

To sign the petition go to: https://petition.parliament.uk/petitions/626737.