Richard Collins: Wild birds are more intelligent than they’ve been given credit for

Experts have found that blue and great tits remember "where they have eaten in the past, where they found the food, and when they found it"

Thu, 18 Jul, 2024 - 12:05

Richard Collins

Tuesday, September 11, 2001: Barbara and I are visiting a small museum in Cuenca, southern Ecuador. We are the only visitors on the day. Suddenly, the curator closes up shop. Thinking that we are Americans, she leads us down to a room in the basement where a television set is switched on. There, over the next few hours, we watch the appalling atrocity unfold at New York’s twin towers. Not only are the tragic details lodged permanently in our psyches, but the time and place where we learned of them are integral to the memories.

‘Where were you when you heard JFK was shot’ moments are extreme examples of what scientists call ‘episodic’ memory — recollections inextricably merged with the personal experience of acquiring them.

But do creatures other than humans have equivalent higher-order recollections? Would a rodent which had escaped from a predator ‘by the skin of its teeth’, retain a once-bitten-twice-shy awareness of that near-fatal encounter? Will a bird, losing its tail feathers in a close shave, become hyper-vigilant where cats are concerned?

It used be thought that only humans could be members of the episodic memory club; no other creatures had the mental sophistication to join it. However, recent research has shown that elephants dolphins and dogs qualify for membership. Jays, with their extraordinary cache-retrieving abilities, are prime avian candidates.

In a paper just published, scientists at Cambridge University describe tests they carried out on blue tits and great tits. These birds have complex foraging lifestyles; they must make on-the-wing decisions in rapidly changing environments. Being able to remember previous experiences when searching for seeds nuts and caterpillars should be a game-changer for them, so can they access personal ‘what... where... when...’ recollections of previous foraging events? Birds as small as these, however, were assumed to lack episodic memory.

The automated, computerised radio-frequency identificationfeeders used in the experiment

The Cambridge study, unusually, did not focus on captive birds. Instead, 94 blue and great tits, living freely in the wild, were fitted with individual radio tags. Automated bird feeders were deployed in their habitat. These logged the identities of birds visiting them. The feeders were programmed to release, or withhold, food of various types being offered to the tits. They created "unique experiences for individual birds and tracked each bird’s behaviour after it had formed a memory".

Would the tits recall previous experiences when confronted with feeding challenges?

Schematic representation of the feeder arrays in the training and test phases across the what-where-when memory experiment

The results of the experiments, the researchers say, show that the birds remembered "where they have eaten in the past, where they found the food, and when they found it", says lead author James Davis. In doing so, they "demonstrate episodic-like memory traits when foraging".

"These findings provide the first evidence of episodic-like memory in the wild and show that blue and great tits have a more flexible memory system than we used to assume. Our findings suggest that these birds are more intelligent than they’ve been given credit for."

Blue and great tits have complex foraging lifestyles: they must make on-the-wing decisions in rapidly changing environments

Nor is this just ivory-tower research without practical implications. The authors claim it suggests "that humans leaving out seeds and nuts for birds could be contributing to the evolution of these memory traits".