First bird flu death in an Australian mainland mammal is a grim milestone. We know how bad this can get

SANKA VIDANAGAMA/Contributor/Getty Images Australia has crossed another grim threshold in its H5N1 bird flu outbreak. For the first time, the virus has infected an Australian mainland mammal: a long-nosed fur seal found dead at Beachport on South Australia’s Limestone Coast, about a four-hour drive southeast of Adelaide. This is a devastating development, although sadly not an unexpected one. H5N1 is already circulating in wild seabirds along the Limestone Coast, with many infected greater…