BDeed's picture

Coastal Shrew

Observed: 30th June 2013 By: BDeed
Merseyside BioBankThe Wildlife Trust for Lancashire, Manchester and
BDeed’s reputation in MammalsBDeed’s reputation in MammalsBDeed’s reputation in Mammals
cs-1
Description:
Identifications
Species interactions

No interactions present.

Comments

BDeed's picture

Sorry, afraid no

Sorry, afraid no measurements... i was scrambling up a scree at the time!

the naturalist man's picture

Shrew

I agree with Gill, by getting the whole tail in the photo you have made ID easier.

Graham Banwell

Visit the iSpot Yorkshire forum for information on events, issues and news relating to 'God's own country'
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BDeed's picture

Thank you both. Is there a

Thank you both. Is there a ratio that can be used if measurements are absent?

the naturalist man's picture

Shrews

ageneral rule of thumb is the tail should be over 75% of the body length for it to be a pygmy shrew; over 50% and it is probably is a pygmy but could be a common shrew.

Graham Banwell

Visit the iSpot Yorkshire forum for information on events, issues and news relating to 'God's own country'
http://www.ispot.org.uk/forum/8411

Gill Sinclair's picture

Tail lengths

The thing I find confusing about the rules of thumb is that some books/guides refer to 75% or 50% of body length, whereas other refer to 75% or 50% of head-body length, and whether the head's included in the 'denominator' makes quite a difference!

Gill Sinclair
OU Certificate in Contemporary Science
www.gillsinclair.net
Twitter @Gill_Sinclair

the naturalist man's picture

Heads or tails?

I agree, it's a case of sloppy writing, and I'm as much to blame for such!

When I, and I suspect books etc., refer to body I mean body including head. With shrews I work on 75% or over definitely a pygmy shrew; 50% or less definitely a common shrew; between 50-75% I go on other features as well. Unfortunately, a lot of the vole pictures recently have been of indeterminate tail length.

I'm going to be doing some work on a large collection of small mammal remains in a Museum in a couple of months. I thought it was just the skulls of around 600 mice, voles and shrews but they have found the vole skins which go with the skulls and I'm hoping they'll find the mouse and shrew skins as well; then I can take my own measurements and bottom this issue.

I don't like taking measurements of live shrews because they die so easily in the hand from shock. Somehow, live it is easier to judge tail length and thickness; you can also see the three tone fur far more clearly than you can in a photo.

Graham Banwell

Visit the iSpot Yorkshire forum for information on events, issues and news relating to 'God's own country'
http://www.ispot.org.uk/forum/8411