Rodent skull ID please

vole-woman · #1 (**permalink**) 19-05-2010, 09:19 AM

I think this is water vole, but I'm suspicious of the un-orangeness of the teeth. It's right next to a water vole colony, left on top of a fence post. By a bird, I presume?

The Woodman · #2 (**permalink**) 19-05-2010, 10:32 AM

Can you extract the skull from the pellet and have a look at the other dentition - the molars?

vole-woman · #3 (**permalink**) 19-05-2010, 10:42 AM

I'll go back tonight and see if it's still there.

Will it have been a buzzard or similar predator, leaving the remains on top of a post like this?

vole-woman · #4 (**permalink**) 19-05-2010, 07:25 PM

Is this any use?

The Woodman · #5 (**permalink**) 20-05-2010, 05:05 PM

Good pic of a vole skull. If the length of the block of three molars is 10mm then its a Water Vole, 5mm gives you Field Vole.

I struggle to gauge length from pics - where's your penny on a string??

vole-woman · #6 (**permalink**) 20-05-2010, 05:29 PM

In another coat pocket.

The size was definitely water vole (sadly). But it just goes to show how pale some w-vs teeth can be.

The Woodman · #7 (**permalink**) 21-05-2010, 06:59 AM

Have you saved the contents of the pellet for your reference collection?

vole-woman · #8 (**permalink**) 21-05-2010, 07:34 AM

I've got a w-v skull already, only the front teeth on that really are bright orange.

How is the molar pattern different between voles and rats?

vole-woman · #9 (**permalink**) 21-05-2010, 07:37 PM

Here's the w-v skull I already have:

and here's the one I asked about;

The Woodman · #10 (**permalink**) 23-05-2010, 07:51 AM

Perhaps I wrongly read your original post!

Yes, the remains on top of the post will have been a pelllet from a bird, possibly a buzzard.

I don't know the answer to why the teeth are not orange but wonder if the digestive acids of the birds gut may have whitened them.

As for the difference between Water Vole and rat dentition (and I don't have the two to compare), I think the root holes for the WV will be arranged in three blocks - similar to the Field Vole. Each molars root will show as one block whilst the rats will individual roost holes similar to the mice. I hope that makes sense.

If you look straight down on a WV's molars, you won't see any other part of the tooth as the sides are vertical and parallel. The grinding surfaces are flat.

A similar view on a rats molar will show the grinding surfaces and also the widening bases of the molars which are not parallel. I've just looked that bit up in Lawrence and Brown.

I have seen rats and field voles incisor teeth that are orangey too. Barn Owl digestive juices do not whiten them.