Bird flu has claimed its first Australian sea lion and dolphin. How does the virus get into these animals?

Stephen Frink/Getty A rare Australian sea lion ( Neophoca cinerea ) on Kangaroo Island has been confirmed to have died from highly pathogenic H5N1 bird flu.

The sea lion had recently been attacked by a shark, weakening it.

Testing revealed the cause of death was the virus .

Another dead sea lion is being tested .

The first confirmed H5N1 death recorded for this species in Australia marks a significant and worrying moment for Australian wildlife.

These sea lions are the rarest pinniped to breed on our coasts.

They’re considered endangered , as their population is under 12,000.

This species of sea lion breeds slowly, meaning even a limited outbreak of bird flu could be very bad news for breeding colonies.

The strain of bird flu now circulating in Australia and New Zealand has evolved to infect some mammal species as well as birds.

Since 2021, it has decimated some seals and sea lion species overseas, especially in South America .

The virus is even capable of infecting and killing dolphins .

But how does the virus pass between these animals? How do seals and dolphins actually get the infection? There’s much we don’t know.

But here’s what we do.

Bird (and mammal) flu? The highly pathogenic H5N1 strain of bird flu (avian influenza) was first detected in 1996.