[F]irst wild beaver spotted in Norfolk in 500 years and Wild beavers may have spread further than we realise:

It is not clear whether the Pensthorpe beaver, whose sex and age is unknown, was illegally released into the reserve by activists using a practice known as beaver bombing. It is possible it wandered of its own accord into the Wensum – an aquifer-fed chalk river whose name is derived from the Old English adjective for “wandering”.
“It could be a naturally dispersing wild beaver,” said Emily Bowen, a spokesperson for the Beaver Trust, a charity that aims to restore beavers to regenerate landscapes. She said that there were established wild populations in eight areas in England at the moment.
Wild beavers have also been spotted in Kent, Hampshire, Somerset, Wiltshire and Hereford, she said. Norfolk has some captive beavers but none have been reported missing.

And if we are talking aquatic mammals, see also otters: otters’ revival in Britain. Still rare only 20 years ago, the charismatic animals are in almost every UK river and a conservation success story.

White storks to be introduced to, believe it or not, Dagenham.

A rather different story: voyaging owls: Two burrowing owls stowed away on a cruise ship out of Miami, and are now living the high life at a Spanish resort before returning to the US next month. We think they may have been in flight from being a threatened species in Florida....