I always tell my kid, be nice to crows, they've got a long memory.
I keep trying to feed them, but while there are crows in the neighborhood, they rarely fly near our house. I wonder if someone on the block was mean to them, once.
Do they really have long memories, or are they just jerks, and people who feel guilty about something they've done mistakenly think their behavior is related?
I ask because I've been dive bombed by crows twice in my life while just peacefully walking, and I've never done anything to them. So I know they can be jerks for no reason.
On a slate-gray Sunday morning last month, a man in an ogre mask trudged across the campus of the University of Washington in Seattle. He passed prospective students and their parents, who paused their tour of the school to gawk at this person stalking the grounds looking like an actor in a low-budget Halloween thriller.
The character in the mask was John Marzluff, a professor who has spent his career studying human-crow interaction. Dr. Marzluff has developed a high regard for the birds’ intelligence. He describes crows as “flying monkeys,” because of their aptitude as well as their large brains relative to their size.
How long do crows hold a grudge? Dr. Marzluff believes he has now answered the question: around 17 years.
His estimate is based on an experiment that he began in 2006 on the Washington campus. Dr. Marzluff captured seven crows with a net while wearing that ogre mask. The birds were soon set free, but, Dr. Marzluff says, the episode traumatized the crows and other members of the murder that witnessed it.
To test how long the campus’s birds would hold onto their grudge, Dr. Marzluff or his research assistants would put on the ogre mask periodically and walk around campus, recording how many crows let out aggressive caws, a sound that experts call scolding. The number of scolding crows crescendoed around seven years into the experiment, when around half the crows he encountered cawed vociferously.
Over the next decade, according to data Dr. Marzluff has collected but not yet published, the numbers of grudge-holding crows gradually tapered off.
During his September walk, Dr. Marzluff recorded in his notebook that he had encountered 16 crows. And for the first time since the experiment began, they all ignored him.
Christian Blum, a cognitive scientist specializing in animal behavior at the University of Vienna, conducted a similar multiyear experiment partly inspired by Dr. Marzluff’s work, using ravens, which are cousins to crows in the corvid family.
“They are also excellent grudge holders,” Dr. Blum said of ravens.
In the study, which ran from 2011 to 2015, Dr. Blum and his colleagues wore a mask and carried a dead raven past an aviary filled with live ravens. They then donned a different mask, a control, and walked through without the dead raven.
Just as in Dr. Marzluff’s experiment, the ravens scolded the “dangerous” mask — even without any dead raven present — with much higher frequency than they did the control. And the scolding lasted for the duration of the experiment, suggesting that ravens’ grudges were also very long lasting.
I have read stories of crows bringing gifts to people who treated them well, and there is an account in this article of two crows who were fed by a person then guarding that person from an aggressive crow.
The article says they're not great at differentiating between individuals that look similar. They may be dive-bombing you because someone who looks a bit like you once mistreated them.
I keep trying to feed them, but while there are crows in the neighborhood, they rarely fly near our house. I wonder if someone on the block was mean to them, once.