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Humpback whale mothers may experience grief when their calves die, a rare observation led by Griffith University and Sea World Foundation has found.

The BBC's Tiffanie Turnbull explains everything you need to know about the sighting off Australia's Gold Coast, and why it's so rare.

Watch: Can humpback whales experience grief? Video, 00:00:54Watch: Can humpback whales experience grief?

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