Here are some barn owl pellets on a centimetre grid...
The three at the front are old (collected on 6th June) and have dried out. The one at the back is fresh and damp and was collected last night after heavy rain most of the day.
Here is a close up showing small mammal bones - probably field vole - sticking out of a damaged end of the pellet. At the time of regurgitation these bones would be safely wrapped in fur...
And this close up shows a rodent incisor - again, probably from a field vole - embedded in the side of the pellet...
Barn owls normally expel two pellets per day and the size varies depending on how successful their hunting has been and how well they have eaten. These ones at 4 - 5 centimetres are pretty average.
Dave P.