Nick Carne
There’s interesting dating news from China. Brains beat looks in attracting birds. If you’re also a bird. Possibly.
A recent study of small Australian parrots known as budgerigars (Melopsittacus undulates) suggests that males who reveal their smarts become more attractive in the eyes of female counterparts.
That’s significant, the researchers say, because it could underlie the evolution of cognitive performance in animals. Perhaps surprisingly, the fitness benefits of cognition, as well as the underlying selective mechanics, have been little studied outside humans.
What sets the new work by a Chinese and Dutch team apart is that it involved direct observation of clever behaviour.
Previous studies with birds have inferred a preference for mates with greater cognitive abilities based on secondary behaviours correlated with intelligence, such as song. However, this does not directly address the role of cognitive ability on mate choice.
In the new study, a team led by Jiani Chen, from the Institute of Zoology at the Chinese Academy of Sciences in Beijing, examined whether female budgerigars altered their preference for males after observing a potential suitor’s ability to do something clever that its rival couldn’t.
The process, which involved more subterfuge than a TV love match program, is reported in a paper published in the journal Science.
In simple terms, it went a bit like this. Females were introduced separately to two males in the kind of setting where they would normally be won over by plumage and vocal ability, and in most cases a clear preference was noted.
Next, the male who looked destined to leave the nightclub alone was whipped away for some secret training in how to open a sealed food container of birdy bar snacks. While this was happening, both the female and the now quietly confident other male had free access to food.
Then the female was asked to watch as, alternately, one male kept opening a food container while the other failed (all the while sitting beside her own sealed container). Invariably, her partner choice changed.
“Our study demonstrates that direct observation of cognitive skills can affect mate preference and, thus, that cognitive abilities may be selected by mate choice directly,” the researchers write.
“This finding supports hypotheses, starting with that of Darwin, that sexual selection may affect the evolution of cognitive traits across animal species.”
It’s not all clear cut, however. In an analysis of the research, published in the same issue of Science, behaviour experts from the University of California, Irvine, in the US, suggest that while “the main result is straightforward, its interpretation is less clear-cut”.
Georg Striedter and Nancy Burley note in particular that because the females did not have to try opening the food containers themselves they had no idea of the complexity of the task and thus might have thought that the successful males were strong rather than smart.
They also wonder whether the extensive training paradigm elicited subtle behavioural differences between trained and untrained males.
But, overall, they suggest the innovative approach taken by Chen and colleagues “has considerable promise for advancing empirical research on mate choice for cognitive traits”.
