National Trust celebrates birth of baby beaver one year after reintroduction

Four animals released in Wallington estate in Northumberland last year have transformed the landscape

The first beavers in Northumberland for more than 400 years have been stupendously busy. There are new dam systems, as well as canals and burrows, new wildlife-rich wetlands and, thrillingly, a baby beaver.

Whether it is male or female remains to be seen. Beavers don't have external genitalia," said Heather Devey, an expert. They are really hard to sex. It's really only through their anal glands that you can tell."