I dissected the Owl Pellet that I found and showed to a few MNA members on our coach trip to Carsington Water. The pellet matched the description of a Barn Owl pellet in the RSPB leaflet “Owl Pellets – How To Study Their Contents” http://www.rspb.org.uk/Images/Owlpellets_tcm9-133500.pdf
“They can be quite large (30-70mm long), smooth and rounded. They are characteristically black in appearance (regardless of the colour of the prey it has eaten) often with a varnish-like gloss when fresh. They are very solid pellets, with the material highly compressed.”
I soaked the pellet in a Petri Dish of warm water and gently teased the pellet apart using forceps. I immediately found three skulls and a multitude of other bones. I rinsed the bones in another petri dish of water before laying them on tissue to dry. After finally prising all the bones free I washed the fur and dried this in a laboratory oven at 50 °C. The bones still looked rather dirty so to clean them further I soaked them in a 13% Sodium Hypochlorite solution (essentially Bleach) for 30min before rinsing again a couple of times in water.
The bones were all from Voles and using information on Vole teeth structure from the RSPB leaflet I was able to distinguish them to be Field Voles (a.k.a. Short-tailed Voles) Microtus agrestis then rearrange the bones to show a typical Vole skeleton.
What a wonderful skeleton ! Even the fibulas are intact. That must have taken a while to arrange.
What are the two bones (a R and L pair) behind the lower jaws and before the first vertebra?
Rearranging the bones was a bit fiddly to say the least. The smallest tarsals were minute only a mm and even with forceps were quite difficult to handle. The two bones you mention are the ear capsules and the small bone beside the lhs ribs is the sternum. Worth the effort though, I’m pleased with the result 🙂