Comment by JohnMakin
6 hours ago
One of the craziest behaviors I have seen was from a murder of American crows in a big city area sidewalk I walk down frequently - occasionally, I have observed homeless and vagrants throwing stuff at them, because sometimes they sleep under the powerlines where the crows like to perch and I think the crows defecate on them or something.
It's well known they can carry grudges, but one day, as I was walking down the sidewalk, a pretty sizable rock smacked the pavement next to me, seemingly out of nowhere. If it had hit my head I would have been hurt. I finally look up and see a big crow staring directly down at me - it had dropped it from the power lines, it had seemingly been intentional, maybe as a warning, I don't know. I attributed it to malice towards the vagrants that harass them.
I was amazed at how much intelligence it would take to 1) form a grudge 2) form intent to threaten/harm, 3) formulate a plan using a weapon with cause -> effect to execute intent, 4) wait for opportunity.
I have observed a lot of very intelligent behaviors from these birds but that was the wildest one. I have seen it happen once since, so I'm convinced it isn't an accident.
Crows in country will wait for a newborn deer to be left alone in a field by their mothers shortly after birth to peck the baby's eyes out so it dies and the crow can eat it later. My neighbor had told me about this happening, and maybe a month later I saw a fawn with its eyes pecked out shortly after it had died. The doe just sat at the edge of the field by it all night. So sad, but really smart of the crows.
Crows have also been known to alert predators like wolves to easy prey so they can pick the remains.
They also do this to lambs, they're smart but evil
second degree planning involving third party means very high social modeling, fascinating
I remember reading an article in National Geographic of how crow's brains are much more interconnected than is the norm in mammals, i.e. IIRC they have a higher density of synapses between neurons. From that article, it seems that the usual brain weight vs. body weight to determine intelligence, which seems can be used to approximate intelligence in different species of mammals, cannot be used for birds (or at least crows, which the article was focusing on).
In other words, they seem to achieve better results with smaller brains than we thought. And yes, crows (in EU) do exhibit some pretty intelligent behavior.
I've read there's also a social aspect - crows are extremely social creatures, as are humans, and other highly intelligent animals like whales. That does seem to be a common denominator.
Regarding that, I'm reminded of another story - on my daily walk near work, there was a dead crow on the pavement. 5 or so crows were standing all around it, doing nothing really. Even me passing close by did not trigger them to fly away or anything, it seemed like they were standing watch on the body. The next day, it was still there, same thing. The 3rd day, it was gone, but the crows were still standing watch in the same manner. I didn't know what to make of it other than it appeared they were mourning or taking part in some type of ingroup ritual. I didn't see it again after that, but it struck me.
I'm not an expert in the area but have read a bunch on this topic to try and understand it better. Bird brains and human brains are structured very differently. Birds are much more like GPUs with independent distributed processing happening in parallel. Mammals have these big bidirectional layers where signals are constantly propagating up and down in a big connected computation.
I wonder what the energy/evolutionary cost of densely-connected brains is. If it's advantageous, why are crows exceptional?
Maybe they require the equivalent of advanced EUV machines to make?
It could simply be an evolutionary "discovery", with no particular advantage over our "brain model". Evolution doesn't seek out optima; it simply encourages genetic structures that improve odds of reproductive success.
Or, to put it another way: if corvid genetics happened upon a brain type that promoted their survival, it doesn't matter if it was "better" or "worse" than the path the monkey/hominid brains took. Genetics took the first bus going in that direction.
They're even apparently able to pass their grudges along to other crows who did not have first-hand experience with the subject of the grudge.
Here is that paper. It's amazing.
https://www.aaas.org/membership/member-spotlight/scientist-j...
They plan pretty deeply - if you think about things like plastic lid snowboarding, or cup sorting games (fit the smaller cups inside the larger) and those types of puzzles, there's usually an abstract reward, whether it's fun, play, revenge, or some future food or whatnot. They tease other animals, will play fetch, demonstrate a rich emotional inner life, and all of those things can be motivations for their complex plans. Throw in familial loyalty, social dynamics, interactions with humans, and it's a recipe for glorious chaos. There's a lot more going on that doesn't cleanly map to most people's conception of birds.
Ravens are wonderful creatures.
I've seen crows pick up walnuts and drop them in front of moving cars so the tires will open them. I had heard that they will do that, but it was still something to see it happen.
Maybe you should be asking yourself what you did to piss of this corvid? They have been shown to recognize faces.
By "sizable rock" do you mean large pebble or small boulder?
A little larger than a golf ball.
Something that produces a loud exclamation in a movie character, but possible permanent brain damage IRL.
[dead]
Oh, crows are WAY smarter than that. If one tried to drop a stone on you, it was because it didn't like your online comments.
My understanding is crows can recognize individuals, so I would think back to what you did to piss off that crow, or that crow's friends.
As demonstrated in humans, the ability to recognize individuals is little impediment to resentment based on group membership.
I was guessing just a general preference towards anyone in their area. I have certainly never done anything harmful towards them.
Crows have been known to harass distinct individuals over others, even going as far as to teach other crows about this person.
I wonder if this was an elder crow whose eyesight has decreased with age and gave out the wrong descriptions to their friends. :D