They would not make the cuddliest pets but tigers are the most popular species for adoption, a wildlife charity disclosed.

Last year 18,000 people in the UK have adopted Bengal tigers under a WWF scheme which lets people sponsor an endangered animal.

The money helps protect the big cats, whose numbers have plummeted by around 95 per cent to 4,000 in the past 100 years, according to the charity.

Polar bears were the second most popular, with 17,000 people adopting one in the past year.

And about 7,000 people adopt pandas, of which, as few as 1,600 remain in the wild. WWF uses the money to help increase the area of habitat under legal protection and creating corridors to link isolated pandas.

Eight thousand people adopt orang-utans, whose numbers have fallen by between 30 and 50 per cent in the last decade. And 3,000 decided to help protect the amur leopard, of which fewer than 35 survive in the wild.

They are found in Primorsky Krai, in the Russian Far East, but their habitat is being destroyed by logging and farming companies clearing the land and forest fires.

In the past year 64,000 people in the UK adopted animals through WWF, raising around £6 million for the charity.

Animal lovers can also adopt dolphins, elephants, rhinos, turtles and penguins through the scheme.

The WWF said that tigers have historically been the most popular animal to adopt. The charity also ran a tiger appeal this year.

Kelly Archer, WWF fundraising campaign manager, said: "Choose from a range of 10 iconic species.

"Whether your favourite animal is the giant panda, a tiger or a polar bear, by adopting a wild animal with WWF you can help protect these endangered creatures, for as little as £3 a month."

The WWF website says: "Adopting an endangered animal is one of the best ways to support it, and to protect the whole species.

"It also helps make a lasting connection with your chosen species, whether it's a panda, tiger, orang-utan or polar bear."