Now I have heard references before to crows being quite smart, but what I witnessed on the way home from work last week really got my attention. As I approached an intersection with construction in progress, I noticed several crows perched on the tops of the traffic lights. The construction crews were gone for the day but because of some cones and plates in the road, the wait for the light was longer than normal. As I waited through a few signal cycles, I noticed the crows periodically swooping down onto the road in front of stopped traffic. There was some sort of fast food scattered across the intersection and these birds were eating it.
At first I thought they were just randomly swooping down when traffic stopped and flying back up when cars started to go. But then I noticed something that made me pull into a parking lot after the intersection and walk back to watch. Whenever the crows swooped down into the road, one would remain perched on top of a nearby pole. The crows took turns being the lookout on the pole and were obviously watching not the cars, but the signal light controlling traffic over the spilled fast food. When the light controlling the turn lanes, (where the food was), turned red, the crow on the pole made a fuss and the others which were waiting on the tops of the various signals would fly down to the road and eat as fast as they could. When the light turned green, the watching crow would make a fuss again and the others would fly back up to wait for another cycle. Every so often a new crow would trade places with the lookout.
A couple of things made me realize their behavior was not just random. First, they always flew back up when the light turned green even if no cars were waiting. I knew this because a car stalled back about 50 feet from the intersection, close enough to trigger the lights, but preventing cars behind the stalled car from getting through. It took a couple of light cycles for the stalled car to get going again and for these cycles the crows flew back up to their perches when the light turned green even though there were no cars driving over the food. Then, after the stalled car moved, a few people who had been frustrated drove through the light after it turned red. This caused a huge commotion with the crows that had started to fly down to the road as soon as the light was red, only to be prevented from landing by the couple of cars running the light. The crows then retreated to their perches and watched and waited through several more light cycles before deciding to continue going after the food. It was very obvious that they knew something was wrong when the light turned red and the cars kept coming and thought to watch the intersection for a while before resuming their scavenging.
Not only were they smart enough to time their eating to the color of the lights, they also knew when the cars and lights got out of sync. They then were smart enough to watch a few signal changes to make sure all was back to normal before resuming their timed swoops down to the food. It is an understatement to say I was very impressed!