Here’s an old bit of news, one of the first things that really made me realize that, “Hey — animals are pretty damn smart after all.”
In the Brevia section of the 9 August 2002 issue of Science, Weir et al. report a remarkable observation: The toolmaking behavior of New Caledonian crows. In the experiments, a captive female crow, confronted with a task that required a curved tool (retrieving a food-containing bucket from a vertical pipe), spontaneously bent a piece of straight wire into a hooked shape — and then repeated the behavior in nine out of ten subsequent trials. Though these crows are known to employ tools in the wild using natural materials, this bird had no prior training with the use of pliant materials such as wire — a fact that makes its apparently spontaneous, highly specific problem-solving all the more interesting, and raises intriguing questions about the evolutionary preconditions for complex cognition.
The original paper is trapped behind a paywall. National Geographic reported on the story when it first appeared, though, and later followed up with a report that crows are actually better at tool-building than chimps. Fortunately, YouTube has video of the crow in question. (YouTube has video of everything.)
Here’s footage of tool-using crows in the wild:
And similar, longer footage:
Where I live, there’s a large population of squirrels and crows. They feed on some of the same stuff. There can be little doubt that the crows keep a close eye on the squirrels, though it’s not particularly clear what they’re watching for. I joke that the crows farm the squirrels. I say this because I frequently see dead squirrels in the street with crows pecking at the corpses. “The crows are just fattening the squirrels so they can herd them into traffic,” I joke to my wife. Yet I can’t help wonder if some of that is not occurring.
Once, driving to work, I came upon a live squirrel standing in the middle of the road. I slowed and waited for it to dart away. “Move, you stupid squirrel!” I shouted. But then I noticed that he was trying to get to the side of the road. But his way was barred by three crows.
Admittedly, I’m reading a hell of a lot into that encounter, but it still startled me.
Those crow videos are amazing. I wonder what species of crow they are. It doesn’t look like our Northwestern Crow up here in BC.
About the squirrels, I believe crows do surround and attack in groups at times. I haven’t double checked that just now. I don’t think they need traffic to kill squirrels, but judging by their tool *construction* (!) and use, they should have the brainpower to use traffic. I’d just think the squirrel would be able to run fast — but, wait, probably the crows wear the squirrel down so he’s disoriented and is easily hit by traffic.
Apparently lots of information (from the original authors?) can be found here:
http://users.ox.ac.uk/~kgroup/
http://users.ox.ac.uk/~kgroup/tools/tool_manufacture.shtml
This includes more videos, background information and science papers with detailed descriptions of the experiments and thorough analysis of the results. (Tho those are pretty dry to read in parts, being science papers after all :)
That crow (“Betty”) indeed was no “ordinary” crow but from a special species from New Caledonia.
Apparently those have over the ages included tool use and manufacture into their instinct. So the fact that she uses tools at all doesn’t mean that she understands what she does.
But on the island the crows are only dealing with twigs and leaves – nothing even remotely similar to garden wire. So at least some part of what the crow did must have been driven by something other than instict.
I absolutely believe that crows do in fact hunt squirrels, at least around here.. I have seen 4 instances where a squirrel was running across the power cables over the street outside our house and 1, sometimes 2 crows would dive, peck at and try and knock the squirrel into the street. I have not seen a successful attack, be we do see a lot of crows scavenging dead squirrels in the road. We also have a large black walnut tree in our yard. when the nuts are ripe the crows will roll or drop them in the street for cars to crush, then dodge traffic to eat the nut meats. I like crows, I don’t like to see them kill or pester squirrels but crows are just using what ever survival skills they can. RIP little squirrels.
I just witness 2 crows kill a baby squirrel right outside my window. When I realized I ran out and chased the crows away but the baby squirrel still died 10 mins later from breathing complications. I think he either was injured severely from the fall or the vicious pecking, maybe both. I don’t think I could have saved him :(