For centuries it has been said that crows never forget a wrong, who hold a grudge and who, furthermore, remain close to their partner for life. Are they legends or is there a scientific basis? In recent years, numerous studies have begun to reveal the complexity of their relationships, giving us a surprisingly familiar picture. Today we know that the crows recognize facesthey remember for a long time who deceived them, they know how to pass on this knowledge to their peers and even reconcile after a conflict. At the same time, they form solid couples, often as long-lasting as a marriage, and precious alliances, albeit with nuances and deviations that depend on the species and context. Both of these characteristics are the result of the extraordinary social intelligence of the corvids, a family that in addition to crows and crows also includes jays, magpies and jackdaws. In other words, research confirms that, between grudges and loyalty, corvids show us a range of behaviors that surprisingly resemble those of our societies.
Crows and rancor: research on the social memory of these birds
Experiments show that crows remember for a long time those who treated them well or badly. In controlled tests conducted by Jorg JA Müller and colleagues atUniversity of Vienna in 2017, ravens (Corvus corax) who had interacted with an “unfair” researcher during food exchanges they chose not to collaborate with him anymore, while they favored the correct one. This memory of the relationship with the researchers lasted at least a month and influenced their future decisions.
But their ability is not limited to the direct experience of the individual crow. In fact, in a famous study conducted in Seattle between 2010 and 2012, researchers captured American crows wearing a mask. Five years later, at the sight of the same masks, dozens of crows reacted by chasing the researchers away, although many had not been present at the initial capture. The young people who had seen their parents chase away that dangerous face they learned to do it themselveseven without having experienced the capture firsthand.
It was proof that knowledge had spread: from the 7–15 crows initially captured, entire communities of crows grew (over a hundred individuals) who recognized the “dangerous face”. An impressive example of collective memory.
Jackdaws, relatives of crows, also distinguish faces and warn of the presence of strangers
Even snow peas (Corvus monedula), little cousins of crows, they know recognize the facial features of individual human beings. In the countryside of Cambridgeshire (UK), a team led by Gabrielle Davidson and Alex Thornton conducted an experiment: observers wore two masks, one associated with a negative experience (disturbance of the nest with manipulation of the chicks) and the other neutral. The parent crows took much longer to return to the nest in the presence of the “threatening” mask and showed more intense defensive behaviors. This shows that corvids they do not react generically to the human presence, but recognize those among men who represent a concrete risk.
Another study, conducted in Cornwall (UK) in 2019, showed that jackdaws recognize a “dangerous man” if they associate it with alarm calls thrown by other jackdaws. Those who heard the alarms returned to the nest more quickly, a sign of more prudent behavior, even without direct experience. In this way, knowledge does not remain confined to an individual but becomes the cultural heritage of the colony: a true animal word of mouth which spreads like an echo from one group to another.
Reconciliations and social strategies
Resentment, however, is not eternal. In the ravens studied in 2011 at Konrad Lorenz Forschungsstelle in Austria by Fraser and Bugnyar, after a conflict the contenders They looked for each other and got closerre-establishing contact within a few hours. This behavior of reconciliation it was much more frequent among partners with strong social ties.
In other cases, as shown by the studies of Massen and Bugnyar conducted in 2014, crows come to interfere in other people’s bonds: of the 564 affective interactions observed, in 19% of cases, a third individual tried to interrupt contact. A tactic that reduces the possibility of rivals forming new alliances.
Fidelity in corvid pairs
As well as holding a grudge, actually, for many species of corvids the couple represents the heart of social life. Jackdaws, for example, always form stable pair bonds, often for life. In a 2000 study of semi-colonial populations in England, the rate of extra-pair fatherhood was zero: an almost perfect monogamy.
But this isn’t always the case. In Israel, recent research with genetic markers, conducted in 2021, revealed that about a sixth of the nests had chicks generated outside the pair. In American crows, according to Townsend, the percentage of broods with extra-pair offspring was around 32%. Loyalty, therefore, is above all social: the couple remains togetherdefends the nest and collaborates in raising the young, even if genetics tell a more nuanced reality.
