Biology: Owl Pellets

Over the last 2 weeks we dissected owl pellets. Owls are really interesting for many reasons.

• Owls can turn their heads as much as 270 degrees.
• They're nocturnal.
• Many species of owls have special flight feathers adapted for silent flight.

and my personal favorite, although not for the fainted-hearted...

• They consume their prey whole, and then regurgitate the undigested fur and bones in a compact pellet that can be dissected.

Still there?  Well, if you can stomach the dissection, (Truth be told, it's more of a in your head gross than an actual gross) this is just about one of the coolest labs you can do!

The first step was to remove all the bones from the pellet.  Next the kids classified the bones, putting each type in a different compartment of an egg carton (is there any craft or science project that isn't vastly improved by the use of egg cartons?!).  Finally the kids used pictures of intact skeletons to identify and reconstruct the prey skeletons they had discovered.  Awesome!

Biology: What are bones made of?

Over the last 2 weeks we have been investigating bones. We tested the effects of heat and acidic solutions on chicken bones. After placing bones in the oven, the kids observed that they became more brittle. On the other hand, bones soaking in vinegar lose their rigidity and become flexible. What do these two experiments demonstrate about the main components of bone? Bone is made up of collagen, a protein that gives bones flexibility, and calcium phosphate, a mineral that gives bone its strength. Heat destroys the protein, and vinegar dissolves the calcium phosphate through an acid-base reaction.

After these experiments, we reviewed the bones in the human skeleton and then did some comparative anatomy as we tried to identify various animal bones.