2. Taxidermy is very important for the study of evolution
especially natural history. All museums of the world
display many preserved animals within dioramas.
Taxidermy focuses on the exhibition of dry, preserved
animals. Birds and mammals are commonly exhibited.
In wet preservation, in the present context, alcohol is
used instead of formalin in various ratios depending on
the cellular and muscular structure of such organisms.
Carl Akeley, has been considered as “the Father of Modern
Taxidermy,”. He was also a naturalist, sculptor, writer and
inventor, and worked for several different museums,
including the Field Museum, serving as Chief Taxidermist
from 1896 to 1909.
Akeley left the Field Museum in 1909 to do contract work, principally
for the American Museum of Natural History (AMNH) in New Yor.k
3. What is Taxidermy?
• Taxidermy is an advanced form of art in the
preservation and restoration of dead specimens for
long term storage and display.
• Taxidermy is a way of preparing, stuffing and/or
mounting an animal for display or study. It usually
involves arranging an animal's real skin over a
model body to make the animal look alive. It is a
way of preserving the body so that scientists or
Museum visitors can see what the animal was like
when it was alive.
4.
5. Taxidermy Techniques
Different groups of animals pose different challenges to
taxidermists:
• Mussel shells and snail shells require almost no treatment and many insects need
only be dried.
• Preservation of vertebrates often involves highly complex procedures, if the
exhibits are for display.
Alcohol preservation:
The simplest method is to place the entire animal in a preservative
solution, normally 70% alcohol. Objects (animals) are often first treated
with formol solution, a fixative which prevents autolysis and tissue decay,
before they are placed into the preservative.
• Mollusks and sensitive organisms such as jellyfish must first be treated
with a fixative. (Formol is toxic and should therefore be replaced with
ethanol after a few days).
6. Alcohol preservation (cont…)
Advantage: Entire organism can be preserved using
alcohol. Generally used for fish, amphibians and
reptiles. The birds and mammals are also sometimes
placed in alcohol (young animals in particular).
Although alcohol causes colors to fade, the groups of
animals mentioned above lose their natural color within
the first few hours. A further advantage of alcohol is that
tissue stored in this way can be used for genetic studies
(DNA) in future. This is why these days tissue samples
are often taken from newly delivered animals and kept
separately in alcohol. Exhibits preserved in alcohol are
often considered unattractive, but for researchers they
are absolutely essential.
7. Pelt
• Pelt is the term used for a skin which
has been removed from the animal and
tanned. This technique is used for
mammals and birds. Hairs and feathers
on the pelt contain important
information.
• Such exhibits form an important part of
mammal and bird collections. Pelts
from these groups of animals keep their
colors, making this method good for
objects destined for display. A further
advantage is that they take up less
space than “stuffed animals” and are
easier to produce than dermoplastic
exhibits.
8. Skeleton
• For both full and partial skeletons, it is necessary to remove all
tissues from the bones. This is generally carried out by the
taxidermist, often after the object has been placed in a maceration
solution/enzyme solutions/KOH solution. The final step is to let skin
beetles (Dermestidae) feed on the skeleton or bones.
• These insects, normally feared by museums, clean all tissue residues
from the bones within a few weeks.
• Skeletons provide important information about the shape and stature
of the animal. Bones and skeletons used for research purposes are
simply kept in appropriate containers, while those destined for
display are mounted back into the original shape of the animal using
supporting elements.
9. Dermoplasty
Dermoplasty enables three-dimensional reconstructions of entire animals. The
starting point is always the preserved skin, the pelt, taken from the animal. In some
cases other “original parts” of the animal are used (antlers, hooves, teeth, etc.).
Until a few decades ago the skin was stuffed with a range of materials including
straw, moss, hemp and even peat (hence the term “stuffed animals”). Today,
however, artificial skeletons tailored to the individual species and body size form a
frame over which the skin is stretched. Cotton wool and wood wool are used to
make fine adjustments to the body shape. In the past, arsenic was used in order to
prevent the skin from being eaten by insects. Today, toxic solution has been
replaced by Eulan (Permethrin based insect protectant), a mixture of two
compounds used in the textile industry to destroy parasites.
Dermoplasty is the most prestigious of modern zoological taxidermy techniques.
Producing an object which is as lifelike as possible requires more than just
dexterity and craftsmanship. Taxidermists must have detailed knowledge of the
animal. This often involves lengthy research and conversations with experts from
the respective scientific fields. Photos and videos provide taxidermists with vital
information on how the animal moves. Such objects are the most attractive for
display purposes but also require a huge amount of work and are therefore mainly
used for exhibitions and presentations.
10. Taxidermy Freeze Dry
• Because of the diversity of specimens being freeze-dried for taxidermy
purposes (from Brahma bull head mounts to minnows used for fishing
bait). The success or failure often directly relates to the proper pre-
freezing of the taxidermy specimen, and the temperature at which the
specimen chamber is held during the drying stage.
• Eutectic Temperature: When frozen, various taxidermy specimens will
totally solidify at different temperatures. The temperature of complete
solidification is the taxidermy specimens eutectic (pronounced yu-tek-tic)
temperature, defined as, "the lowest possible temperature of
solidification for any mixture of specified constituents.”
• An example of the variance found in freezing temperatures is that of
water, all water do not freeze at 32oF. When water is contaminated with
other elements, such as salt, N, Hg, industrial wastes etc., it's
temperature of complete solidification will change. Since one of the
basic premises of freeze dry taxidermy is animals are made up of about
70% water by weight, the importance of eutectic temperature is readily
evident.
•
11. Eutectic Temperature (cont…)
• When determining eutectic temperatures, taxidermy
specimens may be divided into two general groups: those that
contain large amounts of body fats and oils (most fish, certain
species of ducks, amphibians, etc.) and those that do not ( the
majority of mammals, reptiles, game birds, delicate flowers,
etc.) Because of the chemical makeup, taxidermy specimens
in the group (greasy specimens) require lower eutectic
temperatures than the second group (non-greasy specimens).
• Pre-Freezing: Natural salts are usually found in combination with
water in taxidermy specimens, pre-freezing should be done in the
shortest time possible. Slow freezing times leads to salt
concentration in the specimen resulting in lower eutectic
temperatures and increased chance for shrinkage. Rapid freezing
reduces salt concentrations and also results in smaller ice crystals,
which create less tissue distortion.
12. Pre-Freezing (cont…)
• Rapid freezing may be obtained by freezing
taxidermy specimens in commercial freezers
with temperatures of less than -13 degrees F. (-
25 degrees C.) it is generally more economical
to pre-freeze the specimens in a commercial
deep freezer, than use the specimen chamber
as a freezer. Freeze dry machines are most
efficient when "drying" frozen material, rather
than initially freezing the material, then drying it.
The important factor in pre-freezing any type of
specimen is that the specimen is completely
frozen throughout.
13. The Drying Stage
• Once the specimen has been prepared for preservation,
mounted, posed, and completely frozen, it is ready for the
drying stage. the important factor in the drying stage is that
the eutectic temperature is maintained. Because of the lower
eutectic temperature of greasy specimens, a low processing
temperature in the specimen chamber is needed to prevent
shrinkage. Generally this temperature should be as 0
degrees F. and then raised even higher after a period of
time. Using these figures as guidelines, the taxidermist
using the freeze dry machine should determine at what
temperature his work is most successful. Some factors to
consider when analyzing proper processing temperatures
include:
14. • Working in batch loads (all the same type specimen) may be the most
economical way to work, depending on your own situation. Batch loads
allow easy raising of temperatures as the process progresses.
• When working with mixed loads (greasy & non-greasy specimens) one
initial temperature should be decided upon (e.g. -5 degrees F. or 0
Degrees F).
• Some shrinkage may be traded off for speed. Mammals may be run at
slightly higher temperatures allowing slightly faster drying times. The
animals fur will cover most of the shrinking that takes place.
• Not only does a variety of chemical make-ups exist between different
species, it may also exist between members of the same species due to
different diets, and physical environments.
• Because if the lack of air to conduct heat within the specimen chamber,
some differences of temperature will exist inside the specimen chamber
itself. This will require "rotating of the stock".
• The greatest water loss will occur early in the drying stage when the
dried shell is the thinnest and offers the least resistance to water vapor
movement.
15. Economics Of Different Temperatures
• The rate of freeze drying is directly related to vapor
pressure. the higher the specimen chamber
temperature is, the higher the vapor pressure is at
a given vacuum, and the faster the drying is
achieved. The rate of moisture migration from the
specimen chamber, to the ice bank, is a also
related to vapor pressure. The greater the
temperature difference between the specimen
chamber, and the ice bank. for example, a unit with
the specimen chamber set at 5 deg. F. and the Ice
bank running at -55 deg. F., resulting in a
temperature difference of 60 deg. Will move
moisture faster than the same machine with the
specimen chamber set a -5 deg. F., resulting in a
temperature difference of 50 deg. F.
16. Dealing With Greasy Specimens
• Certain steps may be taken to raise the low eutectic
temperatures of greasy specimens. This will allow
the taxidermist to operate the freeze dry unit more
economically at higher temperatures. the first step is
to eliminate the extreme amounts of fats and oils
that cause the low eutectic temperatures. In the
preparation stage, a 20 minute bath in a mixture of
one cup of bicarbonate of soda per gallon of water
will assist in neutralizing fats and oils. Also,
injections of grease tallowfiers, such as antioxidant
will help in preparing greasy and oily specimens for
more efficient freeze drying.
17. Analyzing Specimens
Some of the questions that should be addressed
when considering the right temperatures to
process a particular specimen are:
• Physiology of the specimen?
• Chemistry of the specimen?
• Solid mass of the specimen that can be
removed to speed up the process, and not
effect shrinkage.
