Corvid Tool Use, Play and More
... make them unique among birds.
Posted May 03, 2012
It’s very interesting to learn that crows in the Middle East may use wire mesh to scoop up their cached food, apparently filtering out the sand in the process. I think this is unusual, as this is a pretty specialized tool. It’s one thing to poke out an insect from a burrow with a stick, but choosing a tool that will “filter” reflects even more understanding of the task involved. It’s not unusual, however, to discover that many species of corvids (crows, ravens, magpies and jays) will use tools to assist their efforts in obtaining food. A captive blue jay used a piece of paper to “sweep” food closer to its enclosure after it had fallen outside its cage. Rooks have learned to drop stones into cylinders in order to raise the water level to bring the floating food within reach.
No other crow seems quite as clever as the New Caledonian crow. In the wild, this species manufactures a variety of tools to for use in food foraging tasks. We describe this activity in our previous book, “In the Company of Crows and Ravens”. What’s even more remarkable, is the fact that these species have learned (in a laboratory experiment) to retrieve a tool (a short stick) that is used to obtain a specialized tool (a longer stick) that is then employed to get the food that the shorter stick could not reach. As noted, there is quite a bit of information out there on this species, including a short film showing the crow at work.
In our current work, “The Gifts of the Crow”, Marzluff and I describe many behavioral characteristics that people and corvids have in common. Along with tool use, these birds also spent time playing. Both ravens and crows enjoy tug of war or a game of chase. I have watched hundreds of crows on their way to roost, break formation to dive, hover and float over the top of a water tower whose heated top had created a miniature thermal of rising air. The birds parachuted down over and over again to the tower top to catch the free “elevator” ride back up several hundred feet into the air. After several minutes of fun the crows flew off to rejoin the birds headed for their night roost several miles away.
Crows play for some of the same reasons we do. It’s fun and usually a non-threatening way to develop and apply skills, as well as establish dominance. Their bodies share some of the same pleasure-related chemicals we possess. Endorphins released during play feel good to them. What’s most intriguing about some corvids, is that they play with different species, and there have been a number of internet postings showing crows at play with cats and dogs. My raven, Macaw, was fond of tweaking my husky’s tail and initiating a game of chase through our woods. That this was something that the bird and the dog did routinely during the warmer months convinced me that there was a lot of enjoyment had by them both.
This past winter, I wonder how many of the readers watched the YouTube video of a hooded crow sliding down a snow-covered rooftop somewhere in Russia. From the top of the roof the bird jumps on the inside portion of a lid from a very large jar and slides down the steep slope. The crow repeats the process several times, giving the impression that, like a kid using the round top from a garbage can as a makeshift sled, this bird is having fun. To really determine whether this was the case, we need more evidence; one might argue that the crow was trying to break up the lid to determine if there was food within. Nevertheless, watching the bird repeatedly "sled" from the peak of the roof, and positioning the lid as it did, certainly suggests more than mere foraging behavior.
By the way, an inquiry recently came asking whether crows have funerals. In our new book, we describe a number of episodes where crows were observed gathering in great numbers around a deceased member of their flock. It seems evident hat they seem to be confronting the death of one of their own, and we discuss the benefits of such recognition, but to call it a funeral may be going too far. On the other hand, human funerals benefit the survivors in ways that are similiar to what crows can learn from acknowledging death of another crow with whom they are familiar.
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