Study skins IIIPosted on 14-02-2017 by Becky Desjardins
I have been preparing lots of study skins in the lab. A study skin is a type of specimen, and can be of a bird or mammal. The organs, muscle, and bones are removed, and the skin is stuffed but flat, lying on its back (bird) or belly (mammal). In dutch they are called “Balgen” which is a reference to their slightly puffy shape.
The majority of the bird and mammal specimens at Naturalis are study skins. They are very common in collections because they don’t take up much space. If you had a true mounted animal (opgezet) then it is quite tall and bulky, not to mention very fragile. With study skins you can fit many of them in one drawer. Also, because they are all in the same position, lying down, it is easy to compare them in size and color. Finally, it is very quick to prepare study skins, though mounting an animal in a lifelike pose often takes days. There are other things that can be preserved, in addition to the skin. Sometimes I save the skeleton, or take a wing off and save it spread out, sometimes I save a syrinx, and nearly always I take DNA. All of these pieces have importance.
When researchers come to look at specimens in the collection they can easily see the story of a species. Imagine a drawer of 100 flat merel skins. Some of the are brown females, some are black males, and some speckled young. If you look closer, you can see that some of the birds are smaller than others, even within the same color. When you read the data associated with each specimen, you get even more of an idea of what is going on: the larger birds are from the Netherlands in the winter. But there are also have some larger birds from Scandinavia in the summer. These large birds breed in Scandinavia in the summer and winter in the Netherlands. Now, look closer at the dates and locations of the birds. You can see how the population has changed over time. Perhaps there are no merels from Utrecht before 1900. Or maybe there is a gap where we have no Merels from Friesland from 1970-1980. What does that mean? Was there not enough food or habitat in Friesland? Lots of research can be done from collections.
So I have been preparing study skins of Texas birds and mammals to come back to the Netherlands. So far my favorite is the American Kestrel. This bird is a type of falcon, in fact, the English name for Torenvalk is Eurasian Kestrel. However, the American one looks very different. Red and grey and specked for the males, quite attractive. I have also prepared a Virginia Opossum, which is a type of marsupial found here in North America they have lovely silver fur. Some of the animals I have done are new for the collection, for example, the Golden Fronted Woodpecker and Black-chinned Hummingbird will be the first of their kind at Naturalis. It is very exciting!
Next blog...I start to teach some students….