[NHCOLL-L:5008] RE: flat study skins

[Thomas Labedz]

Steve

 

In my 25 years here at the University of Nebraska State Museum I have
experimented with flat skins for both mammals and birds.  I have no idea how
many mammals I've done this way but well over 400 birds have been prepared
by myself or under my supervision as flat skins.  A useful aspect of
preparing as a flat skin is that you have the opportunity to collect a
complete skeleton.  Before anyone jumps to the keyboard, yes, you can
collect a complete skeleton and complete a round skin as well.  I've done
lots of those too.  What I think the important thing to remember here is,
what is the goal of the specimen?  Is it to document molt in either the
pelage or plumage as part of a research project?  Then yes, a flat skin may
help illustrate/document that quite easily. But, if you are taking advantage
of another type of research that is not enhanced by seeing the inside of the
skin of either a bird or mammal then you might be better off preparing a
standard or slightly modified standard study skin.  Why?  Potential for
future use of the specimens in comparison to older, traditional specimens.  

 

Mammals.  A complete skin and skeleton can easily be done in the form of a
round skin.  I just taught this technique again today to a visiting DVM from
Mexico who will be documenting parasites in mammals and needs to save
vouchers for the host animals.  Takes maybe a whole extra minute in the
scheme of preparation.  You leave one set of feet on the skin, the other
goes with the carcass.  Viola, complete skin for one half the animal,
complete skeleton for the other.  Great for mice, bats, rats, rabbits, and
I've done this for specimens up to the size of bears and leopards.  However,
if you don't want to spend the cotton you can certainly make flat skins.  I
did a series of river otters as flat skins with a lateral incision from the
corner of the mouth, along the limbs, and down the side of the tail.  Total
skin for dorsal, ventral, and one side of the skin, and total skeleton.
Halfway through the drying process I folded the specimen into thirds so it
would fit in a case neatly.  

 

Birds.  Traditional study skins of birds differ from mammals in that they
leave part of the skull in the skin.  On a flat skin, and on beakless round
skins of birds, you lose any characters that may be present because they are
going to the skeleton.  If you can justify that then you are good to go.  A
lateral incision is made from the corner of the mouth, down the neck, around
the wing, down the flank, thigh and leg to toes.  The skin is carefully
pinned to dry with numerous fine pins to keep the feathers along the edges
of the incision from curling under.  Most difficult is the fine extensions
of skin around beak and nares.  To help users visualize patterns on the head
I put a little fluff of cotton under the head skin to give some dimension.
It can take some getting used to mentally grasp what you are seeing with a
flat skin of a bird.  Not unlike looking at a Mercator projection map, you
need to mentally wrap the bird around its body to see characters, but they
are there.  I've done flats of birds as small as kinglets and warblers to as
large as sandhill cranes.  Oh, the feathers off the skeletonized wing can be
saved as potential isotope samples.

 

Both birds and mammals.  In traditional round skins of birds and mammals the
cotton filling acts not only to form the shape of the skin but to absorb
what little oil or grease might be present in the skin.  In flat skins you
don't have that buffer.  The skin must be clean and grease free!  Any
remaining grease or oil has no where to go but onto the specimen, or onto
neighboring specimens.  Money saved on cotton will be spent on washing and
washing and washing the skins to get them grease free.  Even with that,
thicker skinned mammals and feet of birds will ooze some oil.  To help
manage this, and prevent tangling of limbs, I've encapsulated flat skins in
custom made polyethylene envelopes.  Using an impulse sealer I create a
custom fitted package for each specimen.  

 

As far as space saving goes, most collections do not categorize case space
by preparation type and the flat skins will likely end up between round
skins.  Large series that will be together may save space if done as flats.
Even on round skins I'm concerned about space in cases and I will take a
partially dried round skin and squish it down to fit in a single space
drawer in a case.  I've put text books on the breasts of drying prairie
chickens to lower their elevation.  And, I've used a plant press to reduce
the altitude of stubborn armadillos. 

 

Overall I still prefer to do traditional round skins with skeletal material
saved from one side.  I'll be happy to entertain any questions about
techniques.  

 

Thomas E. Labedz, Collections Manager

Division of Zoology and Division of Botany

University of Nebraska State Museum

W-436 Nebraska Hall

900 N. 16th St.

Lincoln, NE  68588-0514

402/472-8366   fax 402/472-8949

tlabedz1 at unl.edu  

 

 

  _____  

From: owner-nhcoll-l at lists.yale.edu [mailto:owner-nhcoll-l at lists.yale.edu]
On Behalf Of Steve Sullivan
Sent: Thursday, October 14, 2010 9:00 PM
To: NHCOLL-L at lists.yale.edu; 'Mammalian Biology'
Subject: [NHCOLL-L:5006] flat study skins

 

I am interested in people's thoughts on flat study skins vs the traditional
round ones.  I see several advantages to flat skins including decreased
storage space needs and ease of preparation.   

 

Related to this topic, I can also see advantages, at least with small
mammals, to making a lateral incision instead of a ventral one, retaining
the toes with the skin opposite the incision but making the remainder of the
skeleton into a specimen, including the toes from the incision side.

 

I have seen a variety of references to these techniques but have seldom seen
many such specimens in collections.

 

Sorry if you got this twice-I did post it to both NHCOLL and MAMMAL since I
suspect there will be some differing perspectives.

 

--Steve

 

Steven M. Sullivan  |  Curator of Urban Ecology 

The Chicago Academy of Sciences and its Peggy Notebaert Nature Museum 

 

Museum  |  2430 North Cannon Drive  |  Chicago, Illinois 60614  |
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708-937-6253  |  Fax 773-755-5199  |  ssullivan at naturemuseum.org 

 

The Urban Gateway To Nature And Science

 

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