'A good day': New Zealand adds area half the size of Auckland to national park

Environmentalists 'stoked' by expansion they say will protect blue duck, native kaka bird, bats and giant land snails

A national park in New Zealand has been expanded by 64,000 hectares - the largest gain for a national park in the country's history.

Kahurangi national park is situated in the north-west corner of New Zealand's South Island, and is already the second-largest national park in the country.