Mystery surrounds penguin deaths in Australian theme park

The birds began dying last Thursday, sparking fears of bird flu. However, tests conducted by Biosecurity Queensland have now ruled that out.

Sea World's manager of marine sciences Steve McCourt said that he suspects the deaths were caused by contaminated gravel that was placed in the bird's enclosure as part of three-monthly maintenance. McCourt declined to say where the gravel came from.

Biosecurity Queensland principal veterinary officer, Ian Douglas, said it might take two or more weeks to determine what killed the birds.

The remaining 12 penguins have been placed in quarantine.