Intraspecies aggression amongst crows occurs for the purposes of protection (protecting mates and family), food sources, as a form of play, and to remove the threat of injured or sick crows.
It can be jarring to see crows fighting each other, and often confusing! Why would they even want to attack each other in the first place?
The reasons given above are very similar if not identical to the reasons given for violence amongst other species (be they birds or something else). However, this does not mean there is nothing unique to crow attacks!
In order to understand why crows attack other crows better, let’s delve into the situations that promote such attacks and what the current consensus is behind the behaviors.
Why Do Crows Attack Each Other?
Crows attack other crows because they are xenophobic and therefore, they don’t tolerate crows from other family groups.
Here are the possible reasons why crows attack each other.
A male crow who has a female mate might attack a strange male crow if that crow appears to be threatening his mate. He is also likely to attack if the strange crow attempts to mate with the female.
In other words, male crows are likely to attack other males when those males violate the perceived boundaries of their female mates.
It is important to note that it seems that crows mate for life. Thus, the seriousness of another male attempting to mate with a bonded female is elevated in comparison to other birds that may not necessarily form such relatively permanent bonds.
Family and Territory
Crows are careful to guard their families and the territories they inhabit. If an outsider trespasses, crows are liable to attack the trespasser.
This form of aggression serves to keep territorial boundaries in place and protect the crows who live there. Note that crows are very social and live in large, extended families. They recognize each other, and therefore know when another crow is an intruder.
This helps make sense of why you might see two crows fighting and wonder why they would attack one of their own. To us, they might look nearly identical, but the crows can tell who is who amongst themselves.
Like many, if not all, species, crows will fight each other for food. This is not surprising given that food is vital for survival.
Crows might attack each other over a food source or over a particular piece of food present at the time. This is usually not fatal for the losing crow, however. (Can crows attack dogs?)
Even though these fights are not likely to end up with one crow dead, it is not unheard of for a crow to kill another crow!
Sick and Injured
Crows are known to literally peck to death a sick and/or injured crow. This is thought to be because the mere presence of a weakened crow might attract predators.
Naturally, if said predators arrive, the entire crow family might end up vulnerable. Killing off the sick/injured crow(s) thus prevents possible invasion by predators and serves to enhance survival rates overall.
While it might seem counterintuitive at first, it makes sense that intraspecies violence might actually protect the survival of the species in the long run.
However, this is merely a hypothesis for their behavior; we are not completely sure why they do it. Perhaps some other reason is at play.
Crows have been known to participate in “funerals” by surrounding a deceased crow. Often, this is an intel mission: They are trying to find out who/what killed that crow. If they do, mobbing might follow.
Mobbing is when a group of crows, known as a murder of crows, seeks out and attacks the predator that caused the deceased crow’s demise. Once again, we are not sure why they do this. Is it for the protection of the species? For the family? Is it revenge? Perhaps it is all of these and more.
Playing with Fellow Crows
Not all crow attacks are hostile, however. Sometimes crows within a family attack each other as a form of play. This is not unlike behavior seen in other species, including us humans! Think about how many times you have seen children play-fight, or even recall times you participated yourself.
Given that crows are known to be intelligent, perhaps it is not surprising that they would engage in playful attacks, and also be able to differentiate between aggressive and just for fun attacks.
Often, animals (birds included) learn by acting out behaviors, as well. So it could be helpful for a friendly crow to playfully attack another as it serves to sharpen their skills in a non-threatening environment.
However, this is not to say that crows never have family fights. Instances of attacks between family members has been observed, but have not appeared to be severe or lead to injury.
Why Do Crows Attack Injured Crows?
An injured or sick crow can attract predators like eagles, hawks, falcons, owls, snakes, raccoons, large dogs, etc. to their territory that can become problem to the whole flock.
When the flock knows about the sickness or the injury of a crow, they either chase them away from the flock or kill the crow to prevent the arrival of the predators in their territory.
However, it is also true that crows don’t attack injured and sick crows always.
Do Crows Attack Ravens?
Crows are always aggressive towards ravens and specially during their nesting season (March – May). Crows attack ravens for food and territory even when they are much smaller in size to the ravens.
Ravens mostly lose the fight from crows because crows live in flocks and ravens live in pairs.
Crows are considered highly intelligent birds, and they have the ability to recognize individual crows as individuals, rather than merely recognizing another crow as simply a crow.
This explains how they are able to accurately attack only those crows who are strangers and actually intruding upon their families, mates, and/or territories.
Without the ability to distinguish other crows, you might observe even more intraspecies violence (because they would have no way to know who is and who is not a stranger and therefore who is and is not a threat).
On the other hand, of course, perhaps such violence would decrease because crows would recognize other crows as another member of their species, regardless of familial attachment or their home territory.
It is often difficult to explain the behavior of other species. In fact, it can be hard, if not seemingly impossible, for us to explain our own behavior as humans, let alone accurately explaining the behavior of crows!
Despite this, however, there is an overall consensus about their actions, with the aforementioned protection of family, territory, and resources being of primary motivation for crows to attack other members of their own species.
Now you will know more about what you are seeing if you happen across a pair (or whole murder!) of battling crows during a birdwatching outing.