Now you are in your bedroom, ready to take the Mystery "Rock" apart!

But before you locked yourself in your makeshift laboratory,
you ran around your house- from kitchen, to bathroom, to garage-
and grabbed some tools that might come in handy...

Which tools do you want to use?

hammer	tweezers	paintbrush	nutcracker	toothpick

You don't have to use them all; it's your choice.
But be warned-- some are going to work better than others...

If you have tried out some of the tools above, then you have already had a glimpse at what's inside the "rock". You may have also noticed that this procedure does not require gloves. Good observation! If this were a dangerous procedure, like if we were using chemicals or touching blood, we would have to be wearing gloves. Good scientists are always careful.

Take a look at this picture of an open "rock".
What do these pieces remind you of?

The pieces are bones, teeth, and fur from the small animals an owl has eaten. Owls eat rodents like mice and voles. This Mystery "Rock" is really an "owl pellet" which is a hard ball of undigested body parts from an owl's meal. It is not uncommon to find them on the ground wherever owls live and hunt. No wonder you found one during your walk!

Can you see any of the bones listed on this chart?

Owls, and other birds of prey, have no teeth. They swallow their prey whole, then absorb the softer parts by digesting them and passing them on to their intestines. However, they are not able to digest all parts of their meal. The bones, teeth, feathers and fur are compressed in the owl's digestive system.

The pellets are not eliminated as feces, but are regurgitated through the mouth.
They cough them up!

Make an observation.
How many skulls are inside your owl pellet?

Owls are not the only animals that cough up these kind of pellets. Hawks, eagles, kites, harriers, falcons, and even robins have been known to regurgitate what they cannot digest!

By studying the contents of owl pellets, you can discover the habits of the owls. What do they eat? How much do they eat? How often? These are the questions a scientist asks.
And there's more:
Do owls change their eating behaviors throughout the different seasons, in different regions, in different habitats? Where do they fit into our food chain? How does a change in the rodent population affect the population of owls? How does a change in the owl population affect the population of rodents?

Let's take a moment to figure this last one out. If scientists have found out that a typical owl regurgitates two pellets per day, how many rodents might an owl eat each day? (Hint: remember how many skulls we found in the dissection.)

Now, how many rodents might an owl eat in a year's time?

If an owl couple had 4 young owlets that they had to feed for the 7 week period it takes for them to mature, how greatly would the rodent population be reduced?

Now that we are done with the dissection, don't forget to wash your hands with soap and water!