Tuesday, 20 November 2012

Club Day. The Birds of Prey Version.

Today was the last session for the fall for the Birds of Prey.  Nicholas has been begging to dissect owl pellets, and today his wish came true.

What is an owl pellet you ask?  Here's the non-scientific definition:  it is a combination of owl puke and owl poo.  Any part of an owl's meal that can't be digested (fur, bones, teeth) is regurgitated in the form of a hard pellet. 

I found my owl pellets locally through one of our used websites - it turns out there was a former science teacher getting rid of his stash of science goodies.  He also provided me with a layout of a vole skeleton and some general instructions for what to do.

We decided to do a trial run last night.  We soaked the pellets for about 20 minutes so that we wouldn't break the delicate bones inside while opening the pellet.  Then we gathered our equipment - tweezers and toothpicks, plus somewhere to put the bones - then drained the water.

We measured our pellet (scientifically yesterday with a tape measure, while today we eyeballed it).  Then we gently broke them open and started sifting the bones and teeth from the fur.  For the boys, it seemed that they had hit treasure when they found the skull or the larger bones of the hips, femurs or humerus's.  We talked a bit about how the skeleton of an animal, such as a vole, is remarkably similar to that of a human (so similar that the bones often have the same names), and how the highest concentration of bones for both mammals are in the hands, feet and torso.  We also talked about how the vertebrae with the larger holes are closer to the head, as the brain stem and spinal cord near the head are larger and therefore need a wider opening to go through.

After a while, they did find it tedious to fish out all the metacarpals, metatarsals (paw bones), ribs and vertebrae.  One Clubber did make an attempt to put together the larger bones of the skeleton.  I was happy, though, to hear their shrieks as they found another bone. 

Treasure, I tell you!

No comments:

Post a Comment