Last fall, senior SUST major and returning adult student Lindsey Sharp was awarded the prestigious Travis Foundation Scholarship at Roosevelt University, a competitive award given to 16 students each year, which enabled her to pursue a Spring 2016 internship at the Field Museum of Natural History. Lindsey worked with specimens in the museum’s mammals lab where she assisted in biological research. Here, she shares her experience and walks us through the steps of specimen preparation.
A word of warning: This post contains graphic images of mammal specimens.
Walking around the Field Museum of Natural History, visitors may be struck by the sheer amount of information available to the public: from the botany and zoology specimens, prehistoric fossil displays, to ethnographic artifacts, the Field Museum’s collections are a treasure trove of important components of our cultural and natural history.
What the average visitor might not know, however, is that the public displays make up much less than 1% of the museum’s over 30 million specimens. Largely used for research purposes, millions of specimens lay in nearly every nook and cranny “behind the scenes.” So how does a specimen collected in the field end up at the Field?
The museum’s researchers and scientists often gather specimens from around the globe, which are first prepared and catalogued before being studied in the Field’s research labs. In this case, we’re going to take a look at a common grey squirrel that was collected here in Illinois. In order to collect useable data, the squirrel specimen must first go through several stages of preparation.
After being sexed, measured, and its reproductive condition recorded, the squirrel is skinned by one of the museum’s many employees, interns, or volunteers. The skin is dried, preserved, and mounted on a foam form for thorough drying in a set position. In order to obtain further data from the specimen, the skeleton must be cleaned. It is here that the museum’s most tireless volunteers come in: the dermestid beetles. The specimens — still full of muscle, tissue, and ligaments — must be cleaned down to the bone, and there’s no more efficient way than through the appetites of thousands of hungry beetle larvae!
After about 3-5 days, our squirrel is ready to be brought down to the Mammal Collections prep lab, where Collections Assistant & Prep Lab Manager Rebecca Banasiak and her team of volunteers and interns finish preparing the bones. In the prep lab the specimens are soaked in an ammonia solution, which draws out the remaining dirt, grease, oils, and fats from the bones. Using tools such as dental picks, scalpels, and even toothbrushes, workers in the lab meticulously scrape, pick, and scrub off any remaining tissue that the beetles weren’t able to polish off themselves.
Once the bones have dried, they are boxed and assigned a 6-digit Field Museum catalog number. Each individual bone is numbered with this unique set of integers so it can never be mixed up with another specimen, and then it is placed into the mammals collection where other researchers will then be able to study them as the need arises.
The prepared bones can give scientists a lot of information. For some of my work with Dr. Julian Kerbis Peterhans last semester, I measured the width, length, shape, and overall size of small sub-Saharan rodent mandibles in order to identify specimens to genus and species level. This research not only tells us which types of rodents are found in a certain area but it also gives us insight as to the dietary habits and preferences of that region’s owl population, as the rodent specimens were mostly harvested from owl pellets collected in the area.
Not every specimen in the museum may find a public-facing home, but every specimen yields valuable information to those studying them. Not only do such specimens aid the museum’s own scientific staff, but these specimens are available for any other scientist, researcher, or student who may need such information for their own studies. After traveling through the museum’s preparation processes, every specimen adds to the growing body of knowledge that is so important in better understanding the world around us.
Submitted 5 April 2016 by Lindsey Sharp