New Delhi, Aug. 6 -- ADELAIDE - For months, Australia's official briefings on H5N1 bird flu carried a careful note of containment. Detections had been limited to individual birds along remote coastlines. No farms had confirmed active infection. The country still had room to manage what was developing.

"The reality is you can't stop native and wild birds flying around, and you can't stop wild animals moving around, and that will mean more mass mortality events like the one we have now seen."

The event they were describing was discovered on Friday, when helicopter surveillance over Cape Jaffa - a remote stretch of South Australian coastline roughly 250 kilometres south of Adelaide - found 49 dead greater crested terns and 35 more that wer...