Surveying Historic Taxidermy Part 3: Results

Our condition survey of historic mammalian taxidermy in the American Museum of Natural History’s Department of Mammalogy (see previous post), supplied an understanding of the most common condition issues affecting them, and clearly displayed their probable causes.

Cracks, Splits, and Dust: Responses to Environment

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Split in the hide at the base of a specimen’s tail.  AMNH/F. Ritchie

It is not unusual to find cracks and splits in historic taxidermy mounts. The organic materials comprising taxidermy (hide, skin, horn, teeth, manikin materials, etc.) will expand and contract as a response to changes in relative humidity and temperature in the environment. This is similar to the way one’s hair increases in volume during more humid days, but is flat on dry ones. If there are small tears or cracks in the hide, they may open up during these fluctuations and become bigger. Much of the historic taxidermy in the Museum is more than 100 years old, meaning it was acquired well before the invention of modern environmental control systems in use today. We were not surprised to discover cracks and splits in hides, teeth, and other organic components.

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Dust accumulation on a glass slide that was placed in a museum public hall for one year.  AMNH/F. Ritchie

Dust may seem innocuous, but it is a serious concern for taxidermy. “Dust” can be anything from lint or dried skin cells to coal dust or other sources of air pollution. These small particles can be abrasive, oily, and/or hygroscopic, meaning that they attract moisture that creates localized varying microenvironments on the surface. Furthermore, accumulated dust detracts from the perceived vitality of a specimen and alters its apparent color; even when the dust itself presents only a minor risk, the aesthetic considerations of display may require investing resources in cleaning methods that could introduce more significant risks like hair breakage, slippage, staining, or disruption of previous recoloring treatments. Most of the specimens surveyed were stored in enclosed storage cabinets or covered by protective plastic sheeting. Mounts in open storage, however, are particularly vulnerable to dust accumulation.

 

Breaks and Loss: Responses to Handling

As mounted skins age, they often become brittle and more sensitive to damage by handling. During the survey the conservators noted broken limbs, detached pieces, and other signs of damage that may have occurred as these objects were handled for various purposes over their long lives. Some taxidermy may have suffered these damages even before entering into the collections. Taxidermy is also vulnerable to damages due to handling during the exhibit installation and de-installation processes, during movement of the collections, and during research. For these reasons, our collections staff follows detailed guidelines that are specifically intended to mitigate these risks.

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Detached toes that may have occurred during the de-installation of this specimen. Detached pieces are stored in the same location as the specimen until they can be repaired/conserved.  AMNH/F. Ritchie

Fading: Responses to Light Exposure

Discoloration and fading in fur is minimized by dark storage. Some taxidermy specimens surveyed were previously on display at the Museum and now exhibit light-induced discoloration and fading, not unlike that seen in the Bernard Family Hall of North American Mammals before its recent renovation. Comparing these discolored examples to the unfaded study skins in adjacent storage can be very useful in determining the degree of fade or discoloration. Where they can be used appropriately, re-coloring techniques have the potential to restore the naturalistic appearance of faded specimens and extend the possibilities for their use in dioramas or other exhibits.

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Specimens of the same species – on the left, the taxidermy examples that were on display for a number of years and exhibit fading of the fur from light exposure. The unexposed unfaded (darker) study skins line the right side of the drawer.  AMNH/F. Ritchie

Other Condition Issues

Several other types of damage were reflected in our survey. These include loss of hair due to old, (currently inactive) pest activity; chemical deterioration of materials used in manikin construction or finishing work, such as rusting metal ear-liners or flaking paint; and structural issues in the base, such as loose attachment of the taxidermy mount and cracks in wood or plaster.

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Squirrel specimen that has lost the nut previously displayed in its mouth. Note also the area of loss of foliage on the display base (yellow area).  AMNH/F. Ritchie

Future Work

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Project Conservator treating loose hide on a moose mount.  AMNH/J. Sybalsky

As the project continues, we will be working to stabilize and restore some of the specimens evaluated in our survey. Examples and case studies derived from these treatments will be shared in the various informational and training resources under development.

 

 

 

Surveying Historic Taxidermy Part 2: Fun Finds

At its outset, execution of our inventory and condition survey of taxidermy mounts in storage in the American Museum of Natural History’s Department of Mammalogy (see previous post) required clarification of what exactly can and cannot be considered “taxidermy.”

What exactly is taxidermy?

The word taxidermy is derived from the Greek words “taxis” meaning arrangement, and “derma” meaning skin. Strictly speaking, a specimen must have preserved skin that is arranged in a lifelike form to be considered taxidermy. Taxidermists achieve this using different materials and methods, but in our survey we considered a specimen to be “taxidermy” if it had an articulated pose and glass eyes (indicating that it was meant to be exhibited). This criteria discounted study skins (preserved specimens with stuffing, but without an articulated pose or eyes), skin rugs (preserved hides with glass eyes and reconstructed head, but without an articulated pose), and mummies (specimens that may appear articulated, but lack internal armature or glass eyes).

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Hutia “mummy” that appears to be in a lifelike pose, but further inspection reveals that there is no internal armature and no glass eyes. This specimen therefore was not considered taxidermy.  AMNH/F. Ritchie

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Rodent drawer of study skins that have glass eyes, but not articulated poses, and therefore are not considered taxidermy.  AMNH/F. Ritchie

The bat collection proved to be the trickiest to classify because a majority of specimens were mounted onto external glass panels. They were not fully articulated internally to form an accurate lifelike pose. It is difficult to pose the thin skin of bat wings, especially of smaller specimens, because, having qualities similar to parchment, it deforms and tears easily.

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Bat specimen mounted to an external thick glass plate. Note the glass eyes and articulated mouth.  AMNH/F. Ritchie

The glass plates provided a way to support the wings while on display.

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The verso of a bat specimen mounted to an external glass plate.  AMNH/F. Ritchie

Many of the bats encountered in the survey had glass eyes and an articulated mouth, a metal wire armature in their wings, and were previously exhibited. For these reasons, we decided they were akin to other mammal mounts and included them in our survey. Half-mounts (also known as shoulder or trophy mounts) were also considered taxidermy, even though the whole animal isn’t represented because the preserved hide is still arranged to mimic a living pose.

 

Taxidermy Materials and Methods

In order to accurately identify the technology and materials used to create the mounts and to appropriately describe the damages we observed, we researched historical taxidermy practices. The choices the taxidermist makes can have an important impact on the condition of the object.

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Splitting skin around a rigid ear liner.  AMNH/F. Ritchie

If the internal manikin is made of excelsior or “wood wool” (slivers of wood, a common material from the late 19th and early 20th century), it will move in response to fluctuations in environmental conditions just as the mounted hide around it does. This movement can eventually cause tension or tears, and loosen the hide from the manikin. Conversely, if the manikin is too rigid, the hide may shrink over time and split open around the internal support.

 

 

 

Small copper-alloy pins added to hold fingers in place can react with the skin to form a waxy-green corrosion product called copper stearate. The corrosion can stain surrounding skin and hair, and can be difficult to remove.

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Waxy green (most likely copper (II) stearate) corrosion on the pins that hold small fingers into place on a display branch. Red arrows indicate areas of corrosion.  AMNH/F. Ritchie

Some glass eyes can also exhibit an inherent deterioration known as “glass disease.” The cloudy appearance or even crizzling (fine cracking) occurs because of a breakdown of the chemical composition of the glass, often exacerbated by contact with skin. Once the disease begins it can only be slowed, not stopped.

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A crack in the glass eye of a specimen.  AMNH/F. Ritchie

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White accretions covering the glass eyes of a specimen, possibly glass disease.  AMNH/F. Ritchie

A future blog post will discuss taxidermy methods in more detail. In the meantime, check out the book Windows on Nature, written by longtime Museum exhibition project manager Stephen Quinn.

Here is a selection of some of the most interesting taxidermy specimens that we came across during our survey.

One of the oldest specimens that we assessed was an agouti that was collected in 1843, before the Museum was founded.

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Image  AMNH/F. Ritchie

The largest mount was an elephant seal that is so large it must be stored in the Museum’s special large species room.

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Image  AMNH/F. Ritchie

The smallest taxidermy specimen was a harvest mouse.

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Image  AMNH/F. Ritchie

The most unexpected specimen (for a North American conservator) was a platypus.

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Image  AMNH/F. Ritchie

The exceptionally skilled execution of historical taxidermy techniques is exemplified by some of the small mammals, like squirrels, that were mounted in dynamic positions. This specimen was acquired through one of the founding collections (Verreaux).

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Image  AMNH/F. Ritchie

Surveying Historic Taxidermy Part 1: Goals and Parameters

Alongside the lightfastness testing described earlier in this blog, we are developing tools to support the efforts of other individuals and institutions seeking to preserve collections of historic mammalian taxidermy. To do this, we needed to deepen our understanding of the historic and modern materials and techniques used in creating these objects, the common condition issues affecting them, and methods of remediation, both historic and modern.

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Taxidermy viscacha specimen from the collection during condition surveying. (c) AMNH/F. Ritchie

Working toward these aims, we conducted an inventory and condition survey of taxidermy in storage in the Department of Mammalogy of the American Museum of Natural History. This survey was intended to accomplish the goals set out above with the added benefit of providing the department with a searchable, data driven inventory of the entire mammalian taxidermy collection. This kind of inventory can serve as a basis for planning and decisions related to collection management and storage, loans, exhibits, and associated conservation needs.

The Department of Mammalogy is one of four departments in the Museum’s Division of Vertebrate Zoology Division. The department’s collection comprises more than 420,000 specimens from around the world, although only a tiny fraction of those in storage are taxidermy mounts. This fraction still represents about half of the mammal taxidermy at the Museum, with the other half on permanent display. These numbers should not be surprising: museum-quality taxidermy is costly to produce and limited in its scientific uses compared to materials such as study skins or skeletons. Instead, taxidermy is valued primarily for display, so it has been produced in relatively small numbers for specific exhibits over the years. Thus, the percentage of specimens on display versus in storage is much higher for taxidermy than it is for other materials that are more often used in scientific research. Among the Museum’s mammal taxidermy holdings are numerous examples from the founding collections that were acquired in 1869 and are now approaching 150 years old. How are these specimens holding up after so many years?

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Project intern Caitlin Richeson examining taxidermy fruit bats in collection storage. (c) AMNH/F. Ritchie

Over a period of four months we spent an average of two to three days per week surveying. We worked around visiting researchers and staff using temporary photography and examination stations in each room. Each specimen took five to 10 minutes to assess, depending on its complexity and accessibility. After opening every storage cabinet and pulling out every drawer to ensure that no specimen was overlooked, we assessed approximately 635 individual mounts in 30 mammalogy-collection storage spaces.

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Project conservator Fran Ritchie examining a specimen at a temporary surveying station in collection storage. (c) AMNH/K. McCauley

Using a custom-built database, we tailored our survey parameters to record identifying information for each specimen, an assessment of its condition, and recommendations for treatment. If desired, the data collected can be exported in CSV and PDF file formats and then imported or attached to records in other existing databases, such as the EMu database system used by the Museum’s Division of Vertebrate Zoology.

Data gathered for each specimen included ‘identifying information’ such as:

  • Specimen Description – Basic taxonomic and locality information, as well as notes about special historical, scientific, or ecological significance
  • Current Storage Location – Building, floor, room, cabinet number(s), and cabinet label(s)
  • Transcriptions – Data from all labels and inscriptions, including taxonomy, catalog and other numbers, and other scientific or historical details
  • Digital Photograph(s) – An overall identifying photograph as well as details of specific condition or preparation issues, when appropriate
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Survey database example entry (not actual specimen in the collection).

We evaluated the condition of each specimen, looking closely at the following elements:

  • Internal armature
  • Skin/hide
  • Fur/hair
  • Antlers/horns/hooves/nails/claws/teeth
  • Eyes
  • Finishing materials (for sculpting lips, nose, etc.)
  • Base
  • Specimen label
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Summer intern Kelly McCauley using the survey database to examine a specimen in collection storage. Note the grey photography paper used to photograph each specimen. (c) AMNH/F. Ritchie

Each specimen was given an overall condition summary, identifying it as Excellent, Good, Fair, or Poor, and further noting whether it is Stable or Unstable, based on the likelihood of existing damage worsening if left untreated.

In the final section of our survey, we recorded the nature and extent of any conservation treatment that would be required to make the specimen stable or suitable for exhibit, such as skin repairs, reconstruction, general grooming, dry cleaning, etc.

Together, all of this documentation will be used to guide decisions about how best to manage, store, and exhibit historic mammal taxidermy at the Museum, while offering supporting resources for the preservation of similar collections at other museums or sites.

Our next post will reveal some of the unique examples that we discovered during the survey.