A conservationist plans to take flight this autumn alongside thousands of swans as they make a 4,500-mile journey from the Russian arctic to the UK.
Sacha Dench will fly by paramotor - paragliding with a propeller strapped to her back - to get as close as possible to flying as the swans do.
Each night she will land close by to observe their habits and hazards.
She hopes to shed light on the steady decline of Bewick's swans whose numbers have halved in the last 20 years.
The first part of the journey will take her across the Russian tundra, a desolate land of extreme weather and home to polar bears, bears and wolves.
There were no roads for the first 1,000km which meant a ground support crew was not an option, she told BBC Radio 4's Today programme.
Ms Dench, a former free-diving champion, must rely instead on good weather forecasting and nomadic reindeer breeders for help, and will sleep in small huts built by hunters for shelter.
She will meet communities along the swans' flight path across 11 countries, including reindeer herders, farmers and hunters.
- Adults are white all over and young birds greyish with a pinkish bill
- They are found mainly in eastern England, around the Severn estuary and Lancashire. The Ouse and Nene Washes, Cambridgeshire, Martin Mere, Lancashire, and Slimbridge, Gloucestershire, are also good places to see them
- They arrive in the UK in mid-October after breeding in Siberia. They winter in the UK's comparatively warm climate, before departing again in March
- In the UK, they feed in fields on leftover potatoes and grain. On their breeding grounds, they eat aquatic plants and grass
A main aim of the expedition was to show the world the "amazing flight" that birds did, linking wetlands between the Arctic tundra and the UK, she said.
She said swans which arrived at her workplace at Slimbridge Wildfowl and Wetlands Trust in Gloucestershire needed safe passage all the way from northern Russia and fewer were making it in the last two decades.
"It's crucial that we act now before it's too late," she said.
'Kind of parable'
Naturalist and TV presenter Sir David Attenborough said the Flight of the Swans expedition was "marvellously imaginative and adventurous".
"That swans should fly from Russia to come here is surely a kind of parable - we can live in harmony with nature and it's up to us to do so."
Actress Dame Judi Dench, who was contacted by Ms Dench after a family member found out they were related, said: "Flight of the Swans is absolutely fascinating, full of adventure and passion. I'm proud to support it.
"We need to work together if we're to help these beautiful birds, and I am looking forward to following the expedition."