Dracula’s Mystery Hair
Hair Identification in Conservation and Collection Care
Hair Identification in Conservation and Collection Care
In Summer 2016, the Haus der Geschichte Baden-Württemberg, a history museum in Germany, asked to borrow a prop bat from Universal Pictures’ 1931 “Dracula” film. This object has long been a favorite of NHMLA Conservation Department staff due to both the rarity of early movie props and to his unique facial features (which suggest that his creator was not overly familiar with bat anatomy).
The two-foot-long bat plays the role of Count Dracula in his animal form. His flexible wire limbs terminate in metal loops, allowing him to be used as a marionette during filming. His wings are made of a dark green textile, and his body and face are carved out of wood. The eyes are thought to be glass beads or pins. The wooden body has a lengthy pelt adhered to its back, and loose hairs of the same species adhered to his stomach.
The root of the problem
This fur is what raised questions in the Conservation Department. Before the bat could be cleared for an international loan, the genus and species of the fur had to be identified for U.S. Customs and Border Protection, and for the U.S. Fish and Wildlife Service.
Unsurprisingly, there are no historical records from the prop house that describe how this object was created – movie props of that era were typically made with as little time and expense as possible, without the expectation that they would eventually be regarded as treasures. One early conservation report identified the “Dracula” bat’s hair as monkey based on visual analysis, which was worrisome since many primates are endangered and therefore not eligible for international loan without special permits.
Hair identification in theory and in practice
Conservation programs train students in the basics of hair identification through bright-field microscopy, polarized light microscopy (PLM) and scanning electron microscopy (SEM). The basis of hair identification is the fact that the microscopic internal and external structures of hairs vary predictably based on species of origin.
Because it had been previously said that the “Dracula” bat’s pelt was from a monkey, NHMLA’s Mammalogy department donated reference hairs from some primate specimens with visually similar hair. The prime suspects were a white-headed capuchin monkey, a black-and-white colobus, and a white-faced saki. These samples were compared to a loose hair from the “Dracula” bat under polarized light. The results were surprising.
The diagnostic features of the Dracula bat’s hair had nothing in common with those of the primates’ hairs. From one angle, this looked like a setback. However, it also meant that Conservation could move on to checking reference samples from animal species more commonly used in the fur trade, which were also less likely to be endangered and legally restricted. Investigation started with reference hair microscopy samples from long-haired commercial fur animals, such as bears and skunks, before moving on to smaller animals. Luckily, the internal structure of a rabbit hair provided by Mammalogy eventually proved identical to the sample from the “Dracula” bat.
In hair identification terminology, the medulla of rabbit hair is described as a double helix or ladder shape, and the cortex is described as resembling corn kernels on a cob. These features are clear in both the known rabbit fur sample and in the “Dracula” bat fur sample.
To double-check these results, a hair sample was mounted for examination with NHMLA’s scanning electron microscope. This revealed that the shaft of the hair was shaped like a dumbbell in its cross section, which is a common feature of rabbits and some other small mammals. The scales’ wavy chevron pattern is also typical of rabbit guard hairs. Naturally, imperfections and damage to the hair also become obvious under this high a magnification, but the overall physical integrity of this sample is good given that the object is almost 100 years old.
The eventual identification of the “Dracula” bat’s toupee as rabbit fur was unexpected given the length of the individual hairs on the pelt. It was also fortunate that while there are eight different genera of rabbits in the world, and huge numbers of different species within those genera, there is only one genus and species of domesticated rabbit on the market – Oryctolagus cuniculus. Different breeds of domesticated rabbits still fall within this same species, even though their fur may look highly variable to the naked eye. The length or color of a given hair does not alter its characteristic internal or external structures. Even hair dyes and other styling methods, which can often be identified under microscopy as well, cannot obscure the species of origin.
This is not to say that hair identification in conservation, or in the forensic sciences, is always this easy. Animals regularly groom their hair, gradually damaging the scales of individual strands. Friction against a hair when removed for use in a cultural object – such as a toothbrush, a wig, a coat, or a rug – inevitably damages it further. There may also be some internal variation among the hairs of one discrete species. Pigs, for example, may grow hairs with either interrupted or completely absent medullae. Hairs from different places on an animal’s body will also show some variation in their microstructure. This is even true for humans.
Stay tuned to find out whether we discover more mysterious hairy objects lurking elsewhere in our collections!