LPS, as the name suggests, causes the birds to become paralyzed, falling from the skies as they lose the ability to fly. The cause of the disease is unknown, with researchers having been unable to find a pathogen or environmental toxin responsible, according to the University of Sydney.

It seems to affect the birds only in the Australian summer months, between October and June, with the highest numbers being impacted in the months of December, January, and February. During this period, thousands of the birds are taken into care to be nursed back to health, which may be an intensive and long-term process.