Sponsored by the
Museum of Natural
Science, Louisiana State University
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?
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.