What motivates whales to make social sounds, and will it matter if the noise from increased shipping means they can’t hear each other?
These are questions that Ms Dana Cusano, from the University of Queensland, hopes to answer using new ecological research funding announced today.
‘We have no idea what whales are saying,’ said Ms Cusano. ‘I’m looking at motivational information to figure it out. Can we tell just by their call if they’re aggressive or fearful, for example?’
She said sounds are related to motivation in land-based animals, including people, but more research is needed to quantitatively assess the relationship between sounds and motivation in whales.
Ms Cusano is one of around 100 students to share in more than $1 million in funds from the Holsworth Wildlife Research Endowment, announced today by the Ecological Society of Australia. Her research will examine the acoustic behaviour of humpback whales on the Great Barrier Reef.
‘They make a few sounds regularly, such as the ‘thwop’, but it’s almost impossible to pinpoint what one call means as it may be used in multiple contexts,’ said Ms Cusano. ‘I’ll listen to the intensity levels of the same sounds in different contexts, such as in groups of males fighting over access to a female, to see if calls change.’
Little is known about the function of whale sounds or the information encoded within these sounds. She doubts she’ll hear specific calls in certain situations, which would imply the sounds may have meaning, like words. ‘It’s more likely whales convey information in the structure of the sound, varying the frequency, pitch and volume depending on motivation, and signalling their sex, age, and size,’ she said.
Ms Cusano said increased shipping around the Great Barrier Reef is a potential threat. ‘The noise of large ships and increased traffic can mask whale sounds. We don’t really know what will happen if whales can no longer hear themselves.’
‘If we can work out how whales use sounds, and how important their calls are, we’ll have a better idea about how shipping will affect them.’
Dr Bill Holsworth has supported more than 830 students since establishing the Holsworth Wildlife Research Endowment with his wife Carol in 1989. The fund is now managed through a partnership with the Ecological Society of Australia. More information about the Holsworth Wildlife Research Endowment is available at http://www.ecolsoc.org.au/endowments