Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

To be fair though, birds have had to adapt long ago to evaluating the movement of very fast moving objects, while rabbits and most mammals have not really had to cope with fast speeds until humans invented cars just a century ago.


But to be fairer (to crows), I've witnessed crows just cross the yellow painted lines in a road to get to safety. They've adapted to our traffic rules.


They 'bomb' the street with walnuts where i live to open them. That's smart but not that impressive. What's impressive is - they don't do it on the parking lots where cars rarely drive, nor on the main road where cars drive constantly. They target pedestrian crossing near the main road, wait for cars to crack the walnut, then eat it.

They understand where the perfect number of cars is gonna be.


And crosswalks are great, as when the light changes, they have the chance to eat it without getting run over.


These particular ones have no lights. But people are still more careful around them so still good idea I guess.


In my experience "without getting run over" is very context oriented with the context being "what city are you in".


In Davis, CA they would perch on power lines holding a walnut in one claw, positioned over on of the wheel paths, and wait until a car was approaching in the appropriate position, and then drop the walnut just before the car arrived. They had a pretty good success rate.

Others just dropped them from high altitudes. I suspect the ones on the power lines were just showing off; as much fun as need.


Could also just be trial and error.


Is there any other form of learning?


humans are able to take concepts and and predict with 100% accuracy what will happen next without trial and error. We also have arithmetic which also is not trial and error.


> We also have arithmetic which also is not trial and error.

How did you learn arithmetic?


We're getting into Hume/Kant territory


Which also sums up most of human history.


Normally I try not to contribute useless comments, but I found this to be a particularly hilarious, laughing-out-loud at my desk observation.


"... and has widely been considered a bad idea." Thanks, Douglas Adams :)


Exploration vs exploitation in action.


Rabbits are prey animals. I don't think(?) crows are.

Prey animals are wary and startle easily to reduce their chance of becoming lunch.


By that logic, they shouldn't be running towards the car that's gonna eat them.


They try to be stealthy and when the car is still going at them they run diagonally towards it, to make it turn and lose momentum. It's a good strategy vs bigger heavy predators, just not vs cars.


Most fast animals can't change direction easily.

Running in almost any direction is an effective means of escape.

Cars are much wider than most predators, meaning many directions end up being bad choices.


The reason rabbits and squirrels run into the car is because they assume it’s like other predators and not taking a path. Squirrels are trying to “juke” and anticipating that the car will respond to that.


I have to think that over time squirrels must be evolving due to cars. I do see dead ones, but I often see them running across the road, and notably not zigzagging. They still don't seem to have a sense of how close and how fast a car is moving though. I've seen a coyote not only assess the trajectory of my car, but change its mind about crossing the road in front of me once I demonstrated I had no traction in the snow.


Squirrels make a beeline for the nearest vertical surface they can climb and hide behind. This is what makes them dangerous to bicycles because they will run through wheels on their mission to get to the tree.


They don't have the planning ability that a predator has. They survive in numbers by breeding like rabbits.


Predators like lions and cheetahs achieve top speeds comparable to a car driving on freeway tho.


For a whole like 8 seconds before it's nap time


And once a day only. If you fail, you starve until the next day.


But that's ambush style... cover, creep, approach, then burst, startle, takedown. Or go hungry.


Are you forgetting the birds of prey?


Where I live, an island right by the mainland, birds of prey are not allowed. If one shows up, the crows will all take to the air, maybe fifty to a hundred of them, and will yell and chase the bird of prey until it leaves the island. Once it is over water, they will give a few last screams and turn around and go back to their business.

I've seen a bird of prey try to dive and swoop low over the land to evade them. They'll follow, some diving down low after it and some at a distance to keep an eye on it, until it's gone.

We basically have a crow air force keeping all the other birds and little mammals safe.


There are many bird species that do the same. Last year in Rotterdam, Netherlands they released a trained American bald eagle from a highrise building to fly to a designated spot across the river. It never arrived there as it was attacked from all sides by other birds, mostly seagulls, and chased across the city. It took hours to find the eagle, and when they did the poor beast was exhausted.


Well, a bald eagle is a glorified seagull, a golden eagle would've fared better.


That's strength in numbers. I saw two crows trying this against an eagle,... I think they only survived that because the eagle was too lazy and figured it was easier to just grab some trainer-provided food after the show. Mind, the crows probably didn't recognize the huge bird, since they're not native here. That one "belonged" to a small wildlife reservoir. The trainer said it was more like he agreed to stay there in exchange for free lunch; which meant after a show the bird would occasionally hit the road for a few days, if he felt like it.



Staying still (minimizing visibility through motion detection) and then moving at the last moment is better avoidance strategy for a bird of prey, unless there's an actual hole they can disappear down.


Well, in his defense, so do rabbits, most of the time :-p




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: