Taxidermists often use paints, hair dye and other traditional pigments for coloring. But for these historic displays, the museum needed a substance that could easily be removed in the future (should better technologies come along). They also needed coloring that would not alter the fur, could be cleaned easily and stand the test of time.
"We didn't want to use paint because the binder in the paint would bind the hairs together," Nunan says. And hair dye would have been difficult because it often requires heat and time to set it and would be difficult to do in delicate patterns, such as those on the jaguar; it also would not easily rinse out. "We were surprised about the limited amount of research that had been done on this," she notes.
The conservation team tested various alternative compounds on sample fur patches, examining them at the museum and shipping them off to be tested in accelerated-aging labs at Carnegie Mellon University and Buffalo State College. There, the samples were exposed to extreme light, heat and humidity to test their ability to stand up to these elements over 10, 20 or 50 years.
Conservationists also needed to match the original 1930s colors of the animals' fur, which was not easy to do—especially because the photographs from the original exhibition preparation are black and white. So Dante and his colleagues were able to borrow historic furs in the museum's collections that had been kept in dark storage to use as the baseline for colors and shading. Each animal also requires several shades, Dante notes. (The American bison, for example, each had eight different colors applied to them.)
But the work paid off. "What we came up with was truly groundbreaking—it will change the way these materials are treated," Elkin says.
The conservation team settled on an ethanol-based dye with metal components to improve color stability, which is similar to those that have been used in textile conservation. And it was light enough that it could be applied with an airbrush sprayer. "It's never as good as the real thing, but it's pretty close," Elkin says. "We've accepted that there will be fading of the dye, but it won't happen in any detectable manner for another 50 years," which, as she points out, will probably be time for another restoration anyway.
In addition to much of the fur, some of the ears, noses and other hard elements needed updating. "Almost all of the prosthetics developed for noses when the taxidermy was created used waxes or wax blends," Elkin says. "Those materials age poorly over time, so the fine detail had been lost." So the American bison and the collared peccary both received nose jobs to restore some of the original texture and fill in cracks. The antelope jackrabbit also had its ears updated to emphasize their signature veins.
Old, faded snow scenes, such as that featuring the Canada lynx and snowshoe hare, had once been created out of medical grade cotton topped with glitter. But by shifting to more modern materials, including silicate fiber that is used to line kilns, chopped up Ethafoam and UV-stable glitter flakes, the conservators hope this new arrangement will retain its white luster for decades to come. Now, notes MacPhee, the diorama looks "absolutely realistic, so you're perched right here on the mountainside next to the lynx."
Other minor touch-ups throughout the exhibit hall were also needed, including a faded rhododendron in the skunk diorama. The conservators carefully studied archive photographs to see where small changes had occurred over time, such as cactus spines shifting or bending.
Finally, to stave off future deterioration of the dioramas and to reduce energy use, the museum reimagined the lighting strategy for the hall. "A large part of the project was focused on re-lamping," Elkin says. For delicate textiles and other artwork, gallery lighting is often carefully controlled and kept at a dim level. The dioramas, however, have different demands. "In the bison diorama, they needed to mimic high noon on the plains—it's a blasting light," Elkin says. Each diorama now has energy-efficient light bulbs and filters "so that UV problem will not come back to haunt us," MacPhee notes.