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 which 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 glycerine in the arsenic. After that time I have always used to mix 4-5% clean glycerine 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 glycerine 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 which 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
&
reseachers. I only toss/donate specimens with no locality data.
I have put together a 'how to
stabalize 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 speciment to see it...so we compromised with the
hole for
easy access to the tag.