Crows Are Smarter Than You May Think

Some years ago, a bird researcher visited a famous institute that deals with primate cognition to give a talk. When the director of the institute introduced the bird researcher and his talk, he used the phrase: “those damned corvids.” No, the director was not a prophet who slurred his speech while talking about “COVID” and predicting a pandemic. He referred to corvids, a bird family that includes crows, ravens, rooks, jackdaws, jays, and magpies. His point was that “those damned corvids” are often equally good in cognitive tasks as primates and sometimes even outperform great apes.

Of course, this was a joke, as animal cognition is not—or should not be—a competition in which the animal that resembles us most in their cognitive abilities wins (Bräuer et al., 2020). But it is obvious that corvids show exceptional cognitive skills.

New Caledonian crow using a tool.

Source: Natalie Uomini, used with permission

What New Caledonian Crows Can Do

For example, New Caledonian crows are renowned for their technological abilities. In 2002, a crow named Betty surprised both researchers and the public in a famous study. She and her male were tasked with selecting an appropriate tool for retrieving food from a mini "bucket" inside a vertical tube. The crows could choose between a straight and a bent wire, but only the bent wire was suitable. In one trial, the male had dragged away the suitable tool, the hook. So Betty took the straight wire and bent it into shape. Then she slid the self-made hook into the tube, fished out the little bucket with food on the handle, and enjoyed her reward. The scientists were impressed, especially since it later turned out that this was not a one-time, accidental action. Betty also bent her own hooks in subsequent experiments (Weir et al., 2002). She did not do this simply out of boredom, but only became active when she needed a hook. When the task called for it, she even bent hooks straight again. Later investigations showed that New Caledonian crows in the wild use sticks, stems, and grass tools, and even follow templates to produce specific tool shapes. In a recent study, it was also shown that these crows select appropriate tools in the present for scenarios they will face in the future (Boeckle et al., 2020).

What Scrub Jays Can Do

Indeed, corvids are also famous for mentally travelling through time. In particular, Western scrub jays remember where, when, and what food they have cached. In another famous experiment, they cached perishable worms and long-lasting peanuts in different trays. The jays obviously understood when the worms would go rotten, so if they only had access to the cached food after a few days, they would only retrieve the nuts—and not the rotten worms (Dally et al., 2006). Even more impressive: They plan ahead for the next day; thus, they cache exactly that kind of food that they will need by then (Raby et al., 2007).

What Ravens Can Do

Ravens, in contrast, are particularly famous for their social abilities (Pika et al., 2020). These large black corvids also cache food, but they are especially sensitive to conspecifics who might pilfer their caches. To secure their stashes, they engage in several countertactics, such as increasing the distance to conspecifics for caching and using obstacles to hide their stashes from view. When conspecifics come close to the caches, ravens even return to the hiding spots and either retrieve the food or defend it. Interestingly, they do this specifically with birds that were in the vicinity at the time of caching, whereas they refrain from going back to their caches with birds that came later. Thus, ravens do remember which conspecific was present when they cached certain food. It is very likely that they understand that only this particular conspecific knows where that food was hidden and might pilfer it (Bugnyar et al., 2016).

Using the Smartness of the Crows

Thus, corvids are indeed “damned” smart and show exceptional cognitive skills that are typical for apes. In fact, some are even abandoning the term “bird brain” and calling them “feathered apes.” Now in Sweden, their cognitive skills—in particular their learning abilities—are even used to keep cities clean. The crows are recruited to pick up discarded cigarette butts from the streets. But what do they get out of it? Food! A startup has created a machine that distributes food for every butt that the crows deposit. What a great application of animal cognition research! It just leaves us with the question raised by one of the contributors of the Swedish pilot project: Why can we teach crows to pick up cigarette butts, but we can’t teach people not to throw them on the ground?