Research reveals complexity of Noisy Miner vocal behaviour
Research at the University of New England is giving scientists new insights into the complex society of Australia’s Noisy Miner.
In a paper published online today in the Royal Society journal Biology Letters, UNE’s Dr Paul McDonald reports that Noisy Miners (Manorina melanocephala) can discriminate among the calls of individuals – even individuals from a distant colony. This is the first publication to demonstrate such an ability in a cooperative avian species. (http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2011.1118)
“The research reported in the paper shows that miners attend to information encoded in their calls – an ability that could contribute to the complexity of their social organisation,” Dr McDonald said. “Given that Noisy Miners call to solicit aid from others, the ability to differentiate callers may underpin the many social interactions in this species.”
“Miner society is similar to ours in some respects,” he said. “A colony – typically comprising 100 to 120 birds – includes relatives and non-relatives that may all work together cooperatively. With their ability to discriminate among the calls of individuals, it’s possible that they can actually identify individuals within the colony from their calls alone.
“The more we look at them, the more complex their society is. Through research such as this we’re finding out that they have cognitive capabilities that 10 years ago we were attributing only to animals such as primates, marine mammals and elephants.”
As well as demonstrating the birds’ ability to discriminate among individuals’ calls, Dr McDonald’s experiments – using a testing procedure pioneered on humans – have shown that that discrimination is based on frequency patterns within the calls. Together, these findings open the way for further exploration of the intriguing world of Noisy Miner vocal communication. By experimentally manipulating a call’s frequency components, for example, it could be possible to isolate the component that encodes information on individual identity.
“Repetitions of a particular call by a single individual show an extraordinary degree of variation,” Dr McDonald said. “So the call could contain a lot of information in addition to that which signals individual identity. It’s exciting: this work is opening up a lot of possibilities for further research.”
“I think Noisy Miners are a very much undervalued species in our environment,” he said. “They’re not just those annoying colonists of the backyard; they’re actually doing things that are pretty amazing.”