From: Johannes Erritzoe <erritzoe at BIRDRESEARCH.DK>
Subject: [AVECOL-L] When is a specimen not worth keeping?
For those of you who have old skins in the collection that
start to crumble I maybe have a solution: Let me start to tell that in the
fifties I got some bad stuffed birds from Italy. I tried to put them in salt
water and stuff them once more, and with a wonderful result, in a few days the
skins were so soft as fresh ones. I wrote the taxidermist and asked him why and
he told me that he used a little glycerin in the arsenic. After that time I
have always used to mix 4-5% clean glycerin in the arsenic.
I have seen many old museum skins which have started to
crumble, and some where pieces from the skin already had loosen, or wings and
tails broken off, often skins of high historic value. The ground substance in
bird and mammal skins are as far as I know the same: keratin, and you know if
you, for example, do not give the spine of a leather book leather oil, wax
or shoe polish from time to time, it also start to crumble as the leather dried
out. Why should the same not happen to bird skins?
For some years ago I got four skins from the Aagaard's Siam
collection, all from 1929 and 1930. That were all soft skins, and if I pressed
a finger on the body to one of the skins, it made a crackling sound. I suppose
because the skin already was too dried up. I restored them all in a simple way.
Some clean glycerin was injected in both head and body. To secure the feathers
the skins were afterwards wrapped up in blotting paper for 2-3 months. Now,
many years later the skins are still soft and no disadvantage has been
observed. One of the skins, Irena puella from 1929 is now housed by dear Kevin
in Fairbanks if anyone should like to see it.
=========================
From: Katrina Cook <k.cook at NHM.AC.UK>
Subject: Re: [AVECOL-L] When is a specimen not worth keeping?
Dear All,
As the collections staff member responsible for bird skin repair at the NHM
Tring, mending an average of 700 bird skins per year, I've been following this
discussion with some interest. Whilst there are always exceptions, the average
repair takes me less than ten minutes and in preference to just sealing the
specimen in a poly bag it can continue to be used and measured in the same way
as before.
Damage falls into two categories; the simplest is that sustained as a result of
poor handling or general wear and tear. Detached or loose body parts can be
mended easily by sewing or gluing, or using fillers where necessary. I would be
happy to share my techniques with individuals who wish to contact me
personally. The other is damage as a result of poor preparation initially, for
example over-dry skin or, most worryingly, fat burn. This is the result of
oxidization of residual subcutaneous fat, becoming increasingly acidic over
time and eventually causing the entire skin to disintegrate.
Cases are usually brought to my attention because the tail or wings have become
detached, also often the scapulars. Handling reveals the skin to feel 'spongy'
and closer inspection shows the skin to have turned yellow and powdery. Small
groups of feathers, attached to tiny fragments of skin, fall out readily; the
skin cracks, usually approximately along the apteria, separating the major
feather tracts.
I have devised a method of dealing with this, but I would be very grateful to
hear from anyone who favours an alternative method
I use the conservation grade adhesive Paraloid B72 dissolved in acetone, thin
enough to be injected through a syringe needle at various points beneath the
skin whilst holding the fragments firmly in place. The acetone evaporates
swiftly leaving the adhesive to consolidate the fragmented skin. It's a
difficult operation to perform without a tiny amount of seepage onto the
feathers in one or two places, but this can be minimized with care and
practice. It's important to work slowly and use small amounts of adhesive
injected into many places. The long term success of this is impossible to
predict, but at least the specimen can continue to be of scientific value for
at least the immediate future and is of more use than loose feathers sealed in
a bag, (though this is occasionally the last resort!)
I usually just glue on the head of
smaller birds, but have found that broken necks of larger birds, that have no
stick, can present a bit of a challenge as Carla says. I've devised a method
that works very well, though. No two cases are the same, of course, so the
technique requires slight modifications according to the individual specimen. I
use those metal chemistry stands to hold the skin in an upright position whilst
working. I then remove some of the cotton or tow from both the neck and head
and put in some stiff filler, making sure this makes good contact with the rest
of the 'stuffing'. I use the conservation adhesive Paraloid B72 dissolved in
acetone, also reversible, mixed with glass micro balloons. This or the
equivalent should be available from all suppliers of archival materials for
museums use. I then prepare a short section of stick, cut it to a point at each
end and, most importantly, cut barbs facing away from each point along its
length to the middle. Push the stick into the filler of the body section and
carefully put the head back on. Any loose torn skin can be pushed into place
thus completely concealing the join. When dry, the backward barbs of the stick
prevent any movement, holding the head firmly in place. It's more fiddly than
many repairs, but usually only takes ten minutes or so.
My solution for putting tails and legs back on is ridiculously simple but very,
very effective. I thread a long needle and tie the end of the thread firmly
around the base of the tail / top of the leg where it should meet the body,
leaving a length of several inches protruding. I then insert the needle into the
hole and out through the breast and back again ant tie the ends firmly
together. That's it! Only rarely on tails do I need to supplement this with a
spot of adhesive afterwards. The resulting mend is perfectly firm and seemingly
as good as new. It took me a while to source needles that were sufficiently
long for this, then I discovered that I could obtain them easily from Teddy
Bear makers!!!
At Tring, all visitors to the skin collection are handed a repair form and
asked to write down details of all damaged specimens on it, then hand the form
and specimens to me. Whenever possible I mend them straightaway and return
them, (though sometimes it means that I have difficulty seeing over the top of
my desk!!)
=============================================
From: Gary W Shugart <gshugart at UPS.EDU>
Subject: Re: [AVECOL-L] When is a specimen not worth keeping? heads and necks
AVECOL: To stabilize broken heads and necks it often works to
use a skewer (for shis-ka-bobs) of appropriate size and drill it up
through the neck into the head. First use fine sandpaper to remove any rough
spots on the skewer that might catch the cotton or other stuffing
material. Then insert the pointy end of the skewer in the belly incision and
twirl it between thumb and forefinger and push it through while holding
the neck/head. As the skewer progresses through the neck watch
the alignment so you don't puncture the skin. If needed the stick can be
anchored in the head, neck or body by injecting archival glue with a hypodermic.
This also works to reattach or strengthen legs by tying them to a stick
extending from the cloacal region. For tails drill through the pygostyle into
the body stuffing and glue to stabilize. The skewer can be clipped off so it
doesn't show or can be left on for a handle on fragile birds.
For larger birds use a dowel and sharpen the end and sand it so it doesn't
catch in the stuffing.
=============================================
From: sam <sam QTY.COM>
Subject: [AVECOL-L] old damaged skins
To: AVECOL-L LISTSERV.LSU.EDU
Why don't you bag 'em?
It takes a few seconds to poly bag a specimen.
The parts will stay together even if not repaired.
The bag will protect other specimens from the grease.
I would suggest mylar bags, but clear mylar might be
hard to find.
https://www.bradleybag.com/
============================
From: "Irene E. Torres" <ietorres
UCDAVIS.EDU>
Subject: Re: [AVECOL-L] When is a specimen not worth keeping?
We are facing this issue with several of our specimens as we execute our
curation grant. As specimens with collecting data are invaluable I would
recommend keeping them (if they have location if date is unknown you can
always put pre-today's date rather than unknown). Badly damaged specimens
should be retired from teaching but kept for historical purposes &
researchers. I only toss/donate specimens with no locality data.
I have put together a 'how to stabilize a specimen' guide to
assist in our
curation that I would be more than happy to pass along to you if needed.
We have found filling a large syringe with Elmer's school
glue and
injecting it into a birds body along the stick helps with loose necks and
loose sticks. I tack loose or broken wings back onto the body with
thread. If the body was made with excelsior it is easy to sew the wing
back onto the body by running a thread right through it. Cotton bodies
are harder to get a needle through.
You can also lay the specimen in tissue paper and fold the
sides up and
lightly crimp them, then make a slit for the tag to show though. This
method is nice as it alerts anyone accessing the specimens that whatever
is in the tissue is fragile and should be handled gingerly. (I got this
idea from Carla at the Bishop Museum). Andy does not like it as you have
to unwrap the specimen to see it...so we compromised with the hole for
easy access to the tag.