Teeth of the Common Shrew

[Bruce Williams]

Hi folks,

This is a follow-up to my recent Macro/Close-up Forum posting entitled Common Shrew (deceased) - With respect. I took the little feller home and managed to take a few stacked shots under the Meiji before the smell became too overpowering.

Beside the two obvious lower teeth, if you look closely you can make out the two upper front teeth, and upper right 1, 2, 3 and 4. You can also just make out upper left 1 and 2.

Eating regular meals means life or death to a shrew. It consumes 80% to 90% of its own bodyweight in insects, slugs, spiders and worms every day. To do this it is almost continually active throughout the day and night, resting for just a few minutes every couple of hours. So as you can imagine, its teeth are VERY important to it.

The red tips to all teeth is caused by iron inclusions in the enamel. This slows down wear on the teeth. Nevertheless after approximately 18 months of almost continuous eating, the red tips will have completely worn away and the teeth then rapidly wear down and the shrew can no longer eat and dies.

Both images are from the same 18 frame, CombineZ5 stack of the underside of the head. I experienced some difficulty with the lighting as, close-up, the whiskers turned out to be unexpectedly reflective.

[rjlittlefield]

Bruce,

This post sent me scurrying across the Internet looking for information about these beasts. In addition to the inevitable Wikipedia article, a good link is http://www.extension.org/pages/Shrews.

If I had ever thought about it, I would have presumed that shrew teeth kept growing for their entire lives. Interesting to find that they don't!

I'm also interested to see that CombineZ5 did such a good job with this stack. Hair is not its favorite subject -- the depth map has trouble jumping from a foreground hair to other hairs behind it. But this example came out great. Perhaps the shine of those hairs helped out the software in this case, by creating sharp contrasts to guide its decisions.

--Rik

[Bruce Williams]

Thanks for your comments and interesting link.

I thought shrew's teeth would continue to grow too as is the case with rodents. I bred hundreds of guinea pigs (for show) back in the 70's and occasionally encountered problems with the bottom teeth overlapping the top, in which case they don't wear down and the teeth have to be clipped and filed. If they were just left they would continue to grow to the point where the animal would no longer be able to eat.

Bruce

[Ken Ramos]

Don't know a lot about shrews, had a guinea pig once that whistled a lot when it wanted to be fed. Interesting shots of the critter though, both posts.

[beetleman]

Pretty soon we will see the Skull of the shrew, right Bruce

[Bruce Williams]

You're right Doug I now have a shrew's skull - and boy is it tiny and so, so fragile! Will have a go at photograpphing it over the next few days - the main question now is how do I mount it for the microscope without damaging it?

Bruce