"Clever rooks repeat ancient fable," BBC News (Thursday, 6 August 2009)
One of Aesop's fables, written more than 2,000 years ago, tells of a crow who uses puts stones into a pitcher in order to raise the water level so he can quench his thirst. Now, two different teams of scientists wonder whether Aesop was actually recounting an observed bird behavior, rather than simply making up a fanciful story.
A study published in Current Biology reveals that rooks, a relative of crows, do just the same when presented with a similar situation.
Christopher David Bird and Nathan John Emery, "Rooks Use Stones to Raise the Water Level to Reach a Floating Worm," Current Biology, 06 August 2009.
If you watch this clip, you'll see the rook study the tube of water. He sees a worm floating in the water that he'd really like to eat. Then the researcher puts a stack of rocks in the rook's cage. Immediately, he starts picking up rocks and putting them in the tube to make the water rise. What's even more amazing is that the rook puts in exactly the right amount of rocks to get the water level just high enough so he can reach down and grab the worm snack.
In another experiment, the rooks were presented with a similar scenario. But this time they were given a combination of stones of various sizes - some small, some large. As you can see in this clip, the rook grabs the larger stones first, which (ironically) accomplishes the job more quickly.
A different study shows that New Caledonian crows - which like rooks, are a member of the corvid group, along with ravens, jackdaws, magpies and jays - can use three tools in succession to reach a treat.
Joanna H. Wimpenny, Alex A. S. Weir, Lisa Clayton, Christian Rutz, and Alex Kacelnik, "Cognitive Processes Associated with Sequential Tool Use in New Caledonian Crows," PLoS ONE 4(8): e6471.
Captive crows were presented with several horizontal tubes. One of the tubes contained some out-of-reach food. The others contained long and medium-length hooks - but, again, these were all out of beak's reach. And a shorter hook-like tool was positioned nearby.This clip shows the experiment in action.
The researchers found that the birds picked up the short tool, then used this to grasp the medium-length tool, which they then employed to retrieve the longest tool from the tube. Finally, they were able to use this to drag out the tasty morsel.
Four out of seven of the birds tested were able to use three tools in the right order, the team said...[T]he complexity of the task made it unlikely that the crows were solving the problem using trial and error.
So what are we to make of these birds' ability to be innovative tool users? From an evolutionary perspective, this data would likely be interpreted to mean that an ancient ancestor of the corvids might have evolved the capacity to use tools, and that all members of the corvid family inherited this ability. From a creation model perspective, however, this same data is consistent with the nephesh quality of birds described in Genesis 1. Apparently, God created this particular class of birds with exceptional intelligence, that which rivals the primates.
Another brief point - One of the common arguments that I hear is that tool use and reasoning skills by hominids is an evidence that they are "human." But I beg to differ. It's obvious from these birds that tool use and intelligence don't make an animal "human" anymore than walking on two-legs makes something a turkey. Whenever these studies come up about animals using tools, I always make a point to talk about it with my daughter. I want her to marvel at God's creation and see what a creative Designer He truly is. I also ask her the question, "Do hominids use tools?" "Yes." "Do birds use tools?" "Yes" "Does using a tool make an animal a human?" "No." No, it doesn't. It simply demonstrates its nephesh quality. Although humans are also nephesh creatures, they are also the only creatures who were are created in the image of God.
I guess even smart birds know that necessity is the mother of invention.