What is intelligence?
Intelligence is described as the ability to acquire and apply knowledge and skills. While this may work in the human world, this may not be the case for the majority of the animal kingdom. Every year there appears to be an ever-increasing number of animals displaying “intelligent” behaviours, so perhaps it is time to redefine what we count as a “smart” animal.
Who are these “Clever girls”?
We often assume mammals are the most intelligent of groups, possibly because we are one. Every dog or cat owner you ask will regale you with the apparently unique traits and behaviours that make their pets a genius; and the science backs them up (1,2). Cetaceans, otherwise known as dolphins and whales, are universally renowned for intelligence with their complex behaviours and social structures. Rodents, such as rats and mice, are also considered clever from their extensive use in scientific research (3). But are we being short-sighted? Are there more intelligent animals that are being overlooked?
Not so bird brained
Corvids, such as crows and magpies are considered the most intelligent family of birds, with the exception of some parrots. It’s been found that wild crows can recognise individual human faces and can hold grudges against those who have treated them badly. Although this appears somewhat ominous, it’s not all misgivings, crows that take a shining to you might just leave you shiny gifts. An eight-year-old from Seattle started receiving gifts from the crows that she routinely fed via her garden feeders. Her collection is largely made up of beads, scrap metals and glass, we all know the old wives tale of thieving magpies and their penchant for shiny objects. These gifts are made up of objects that are considered precious to the birds and indicates that these animals have a sense of monetary value, or at the very least a preference to some objects over others.The New Caledonian crow (Corvus moneduloides) and its intelligence has been studied intensively and these ingenious animals appear to have culturally changed their methods of tool manufacture over time (4). It wasn’t until an aptly named bird 007 completed an 8-step problem in less than three minutes did the world outside of academia take notice (fig.1). Within this experiment, some of the most difficult sections echoed Aesop’s fable, where a thirsty crow drops stones into a water vessel until it is high enough for the bird to drink. To understand the displacement of water and to complete this task indicates that these birds have the mental ability a kin to that of a seven-year-old child. Something not to be scoffed at (fig.2). On a more emotional level, corvids, similarly to elephants, have been observed grieving their dead. Crows which come across a dead member of their species will call and gather other crows in the area, which can be perceived as an almost funeral like event. It is unclear as to whether this gathering is help the birds observe a threat and learn how to avoid a similar fate as the dead bird or whether it is indicative of something deeper.
However, these examples may not have you convinced. So what, birds aren’t as bird brained as we previously thought, why does that mean we need to readjust our views of animal intelligence? To many people insects are just creepy crawlies, something you find lurking under overturned rocks. But they are part of a highly diverse group of invertebrates, with just under a million-known species, and with countless forms remaining undescribed.A paper published in October 2016 described the apparent social learning and cultural transmission of learning within a population of bumble bees (Bombus terrestris)(5). Individual bees were presented with three artificial blue flowers attached to string underneath a Perspex barrier, and had already associated positively with these blue flowers previously. Prior to being demonstrated how to pull the strings, none of 291 individuals could complete the task in their first five-minute test. However, over half of a sub-group of 40 bees were able to be trained in a step-wise fashion to pull on the strings in less than six hours (fig.3). And more importantly, two bees in Colony one were able to instantaneously learn to pull on the strings to reach the blue flowers, although it did take considerably more time. These bees are known as innovators and could be a key into how intelligence evolved through geological time.
These seemingly complex skills can be learnt through simple mechanisms and individual who learn from a demonstrator can then go on to become demonstrators themselves. Something you may not have excepted from the humble bumble.
Do we need to rethink what we count as intelligence?
Intelligence is a complex combination of behaviours, cultures and innovators. We may see ourselves as the pinnacle of intellectual evolution and our single-mindedness blinds us to the intelligence being displayed within the animal kingdom. Birds and bees may not be on their way to overthrow our society Planet of the Apes style but they are certainly much cleverer than we give them credit for.
- Cook. “Inside the Dog Mind” Scientific American Mind 24, 28-29 (2013)
- W. S. Bradsha et al., The Behaviour of the Domestic Cat. CABI (2012)
- B. Bartel, J. Decety & P. Mason. “Empathy and Pro-social behaviour in rats” Science 334 (2011)
- Chappell & A. Kacelnik. “Tool selectivity in a non-primate, the New Caledonian Crow (Corvus moneduloides). Anim Cogn 5, 71-78 (2002)
- Alem et al., “Associative mechanisms allow for social learning and cultural transmission of string pulling in an insect” PLoS Biol 14 (2016)