Looking at the mammal and bird skins in the OSU Tetrapod Collection, visitors commonly have some questions:
“Where did the specimen come from?”
“What did you do with the insides of the specimen?”
“Why are the specimens’ eyes white?”
To properly answer these questions, we need to go back in time to when naturalists, such as Charles Darwin or John James Audubon, went out into the field to collect specimens. When they captured a bird, they would remove the insides of the specimens to ensure that the skin would not spoil and rot before other naturalists could view and study it. Today, we continue to use very similar methods to preserve specimens, as well as new methods such as freeze drying. – Now going back to the visitors’ questions:
“Where do the specimens come from?”
Trays of prepared waterfowl specimens laid out to be reorganized.
In the past collecting birds and mammals was a very active process, very similar to today’s trophy hunting. Collectors would go out with shotguns, mist nest and traps to catch animals and collect them. Today, the most common way of getting specimens for collections is by salvaging already deceased animals. To do this, our collection possesses special permits (known as salvage permits) allowing us to salvage birds and mammals from all over the state of Ohio.
“What do you do with the insides of the specimen?”
The tendons found inside the tail of a North American Beaver.
We remove most of the bones and tissues of specimens during preparation, and the carcass is used in two ways: Most carcasses we examine internally to determine the sex of the specimen and to look at the animal’s last meal. This will provide some information about the ecology of the animal, what and where it has been feeding. Once that information has been recorded the carcass is disposed of. Rare specimen carcasses are put in a tank of dermestid beetles for a couple weeks till only the bones remain. Once cleaned, the bones are added into the collection for future research use.
“Why are the specimens’ eyes white?”
A row of Rose-breasted Grosbeaks males.
To ensure that our specimens will last 500 years or more we remove as much of the organic material as possible. This means that we remove the eyes, brain, body and a majority of the muscle tissue. After removing the organic tissues and matter, we fill the now empty skin with white cotton to represent the body 3 dimensionally. Since the eyeballs have been removed the white cotton in the inside of the head is visible through the eye sockets – hence the white eyes. By removing most of the organic material, we reduce the potential for attracting museum pests, such as the dermestid beetle also known as the flesh-eating beetle – you can imagine what this beetle would do to a specimen with intact insides.
Today, the traditional method of preparing specimens by skinning is slowly being lost. Newer methods of freeze drying specimens, using large freeze drying machines that pull all moisture out of the specimen, have become more popular. Freeze drying allows for more organic material to be preserved which in turn provides more material to use for DNA testing of specimens. In our collection, we do a combination of freeze drying and traditional methods of preparing specimens, depending on size and overall condition of the specimen.
How Can You Help?
To add to our collection we need citizen scientist, like yourself, who find a dead bird or mammal, write down the day and place where they found it, and donate it to the collection. On average, we get 10-15 new birds a month, which we put in a freezer to prepare at a later date. These specimens once accessioned will “live” in the collection for a century or longer.
Something to note: without proper permits, a citizen is not allowed to possess a deceased migratory bird, due to the Migratory Bird Act (more info at http://www.fws.gov/laws/lawsdigest/migtrea.html).
About the Author: Stephanie Malinich is the Collection Manager for the Tetrapod Collection.