Australia on Saturday confirmed its first mainland case of the deadly H5 strain of bird flu.

The disease was detected in a migratory sea bird — a brown skua — in a remote part ‌of ⁠Western Australia, Agriculture Minister Julie Collins said at a press briefing in Canberra.

The development means that the highly contagious variant of avian influenza is now present on every continent.

"We all knew we couldn't be bird flu-free forever," Collins said.

What do we know?