Sumatran tigers are a critically endangered subspecies from Indonesia, of which fewer than 400 remain, according to the conservation group WWF.

CNN: Tiger kills zookeeper in New Zealand

Edinburgh Zoo have replaced the Amurs with a young pair of Sumatran tigers.

BBC: Aye of the tiger as pair go north

Sumatran tigers are also a critically endangered species.

BBC: Aye of the tiger as pair go north