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.