Four beaver families were caught in the Telemark region of Norway
Four beaver families have arrived in the UK as part of a historic plan to reintroduce the mammals to Scotland for the first time in more than 400 years.
The beavers were flown into Heathrow Airport on Thursday night from Norway.
They will spend six months in quarantine before being released in Knapdale, Argyll, on a trial basis in spring 2009.
The release will be the first-ever formal reintroduction of a native mammal into the wild in the UK.
The Scottish Beaver Trial is being carried out by the Scottish Wildlife Trust and the Royal Zoological Society of Scotland.
The beaver families - each consisting of one adult male, one adult female and between one to three yearlings or kits - were captured in the Telemark region of Norway in September.
Iain Valentine, from the Royal Zoological Society, said the captures had been a "complicated process".
"The team in Norway spent long periods of time in specific sites to identify complete family groups, ensuring that none are left behind," he said.
"Another added complication was that beavers are primarily active at night so the beaver families were tracked from boats patrolling the river and caught in the dark.
"The team in Norway did a fantastic job and all the beavers are in excellent health."
When the families are released, the project partners and Forestry Commission Scotland will continue to oversee the project.
Scottish Natural Heritage will conduct scientific monitoring to assess the environmental impact of the beavers.
Simon Jones, from the Scottish Beaver Trial, said: "Beavers are native to Britain but were hunted to extinction over 400 years ago.
"Beavers hold the potential to create new wetland habitats which in turn increases the appeal to other native species.
"We are excited to get the trial underway and really see what benefits beavers can bring to Scotland."
The scheme to reintroduce the mammals, however, has not been without controversy.
The Association of Salmon Fishery Boards has called the project "recklessly irresponsible" and asked ministers to block further releases until the impact on fish stocks can be assessed.