In my opinion there isn’t one system to do things correctly in taxidermy, every museum or taxidermist may have their own preferences and strategies already in place. This is simply a guideline that works for me, and I hope it can help others to mitigate some of the problems I encounter when working with skins that have been frozen in a way that has accelerated freezer burn. Following this advice might get more time out of frozen specimens and give you a greater chance that they can be mounted once the budget or staff time is there to pay for taxidermy or processing cabinet skins.
What is freezer burn?
Freezer burn happens when the moisture is evaporated out of the animal’s skin and muscles over time in the freezer. Most specimens even if they are well packed in the freezer will still get some freezer burn over a long period of time but it will be much worse if the specimen is poorly packaged or has something absorbent (like a paper label) inside the bag with it.
You can tell if a specimen has freezer burn because it will look white and dry in areas such as the feet, hands, around the eyes, ears, and mouth. And when you start skinning the skin will be yellowed and hard to remove rather than red, fleshy, and easy to peel away.
Firstly, I advise to always freeze your specimens before handling or skinning them. At a minimum you could record the specimen’s weight before freezing as this measurement is affected slightly after freezing. I personally would not take any other measurements until after they have been thoroughly frozen (unless you want to collect live parasites). As the animal dies, any parasites on the skin of the animal will leave the body as it cools and hop onto the next willing subject which will be you or any living creature in your lab! A note that fleas are not killed over night, if you freeze a fox for example leave it in there for at least two weeks before defrosting. It completely depends on the temperature of your freezer however so if you start to defrost an animal the fleas will defrost first, so if there is movement you know to refreeze! Obviously very large animals may need to be skinned straight away, so in this case my advice is wear appropriate PPE.
A key aspect of taxidermy is that it permits the viewer to forget the animal is dead – something that is rather hard to miss when considering skeletons, specimens preserved in fluid, or insects with a pin stuck through them. Allowing ourselves to be tricked into thinking we are looking at a living, breathing – albeit very still – creature is surely one of the reasons that museum visitors so often ask, “Is it real?” when encountering taxidermy on display.
Eventually, it is the stillness that breaks the illusion, along with the obvious realisation that, no, it simply isn’t possible for a live tiger/antelope/walrus to be sat there behind glass in an urban building.
In April 2019 Holly Morgenroth (Collections Officer at The Royal Albert Memorial Museum) gave me a call to say she had acquired a dead beaver that was in good condition for taxidermy. This was significant because this beaver was part of the River Otter Beaver Trial. All deceased beavers should now be sent to the Zoological Society of London for medical autopsies, which means they are usually not in good enough condition for taxidermy after the procedure. This particular beaver, originally from a population of beavers in Scotland, had been introduced to the River Otter in April 2019 to expand the gene pool of the population. Sadly she was found dead – it is possible she drowned in salt water as there were no visible injuries from conflict or a road traffic accident. Devon Wildlife Trust decided she did not need a post mortem and very kindly handed her over to Holly at the museum. Holly jumped at the opportunity and expertly packed her into a large plastic tub and placed her in the museum’s chest freezer and got to work obtaining funding to have her processed into taxidermy and a full skeleton.
This blog post tells the story of a new and very important acquisition for the Royal Albert Memorial Museum & Art Gallery (RAMM) in Exeter. I grew up in a small Devon village called Otterton and spent many happy hours wandering the banks of the River Otter observing the rich wildlife it had to offer. So when in 2013 news broke that a family of beavers (a species extinct in the wild in Britain for over 400 years) had made the river their home I watched with great interest.
Their arrival divided opinions. The Government planned to remove them from the river. But the beavers captured the hearts of the public and Devon Wildlife Trust (DWT) saw a unique opportunity for research. The beavers became part of a five year scientific trial run by DWT to assess their impact on local geography, ecology and people. The results of the trial were overwhelmingly positive.
Written by Becky Desjardins (Senior Museum Preparator & Conservator), Georgia Kay & Kim König (MSc students Museums & Collections – Leiden University; Naturalis Interns), Naturalis Biodiversity Center.
Back in 2013, Naturalis conducted a research project about arsenic in the museums’ specimens. The goal was to determine if arsenic was spreading from the collection areas into staff and or public areas of the museum. We tested many specimens with an XRF but also tested the elevators, door handles, floors, shelves, keyboards, etc. From this testing we developed protocols about handling specimens and how we use the spaces in the collection. You can read all about that project over here.
What didn’t get tested were the large mounted vertebrates. Back in 2013 the Naturalis collections were spread over a number of warehouses around Leiden. Because these external buildings were considered depots only (meaning no offices/canteens in these spaces) there was less concern about arsenic contamination in non-collection areas. The large vertebrates were considered to be high risk specimens (so very toxic), and were handled as such, they never had their moment with the XRF.