Australasian Science: Australia's authority on science since 1938

What Makes Baboons Bold?

By Stephen Luntz

Behavioural ecologists need to rethink their measures of animal boldness after two tests, supposedly for the same characteristic, did not correlate in baboons.

Dr Alecia Carter made a name for herself as an Honours student studying friendship networks among kangaroos (AS, October 2007, p.43). For her PhD at the Australian National University she looked at baboon personality.

“It makes sense for animals to adopt the optimal strategy in any given situation,” she says. “But if you’ve ever owned a dog you’ll know they act differently to other dogs faced with the same situation.

“What I want to know is why they act differently. Is there an advantage to adopting a different behaviour? For example, bold individuals may gain greater access to resources, but timid ones may be less likely to be eaten by predators.”

However, in the course of her work Carter saw problems with personality trait definitions. She tested boldness by presenting the baboons with a stuffed puff adder and found that the baboons most likely to flee the snake also spent the longest examining it when they eventually approached. This contradicts the idea that absence of alarm and time spent examining a novel object are both measures of the same trait.

Moreover, Carter revealed in Animal Behaviour an absence of correlation between these responses and reactions when presented with a dyed hard-boiled egg. As an object they had never encountered before this provoked a range of responses. “Some of the baboons were very wary – they wouldn’t even approach the egg, while others went over and sniffed it and decided: ‘Hey, this is something I can eat’,” she says.

“These findings highlight that current boldness assays may not be interchangeable, and in some cases may not measure boldness at all.” Carter argues that what has been considered a lack of boldness may be better seen as anxiety. She describes anxiety as an “uncontrollable response” while boldness is a more deliberate choice.

“You can’t find a test that measures just one personality trait,” Carter argues. “To separate them you have to do a lot more work.”

Carter is extending her work to meerkats, while hoping to measure the inheritance of personality traits and explore the evolutionary advantages of greater boldness. “I thought the bolder baboons would be more likely to take advantage of food sources at the periphery of the troop’s range, but I tested for this and found nothing,” she says. “Perhaps the baboons just don’t like me and were sabotaging my project.”