The Skinny on Birds

Earlier I told you about a scientist who made a collection of birds in Chicago that had met their demise by running into buildings. After forty years of collecting, he decided to measure the birds in the collection and found that they are getting smaller, apparently due to global warming.

Bird skins are important for long term studies. For many years in the past birds were shot for study or for artistic models. Audubon and others shot them and wired them in more or less realistic poses. Photographic techniques good enough to capture birds in the field didn’t come about until the early 19^th century. And for many years before and after that, collectors filled their “libraries” or personal museums with preserved birds. Old time scientists and naturalists collected birds for study and research. Fortunately, today the intentional killing of birds to fill museums is a rare event.

Museum collections of birds are valuable insights to conditions of the past. Have birds of a certain species changed color or size or shape? Have they disappeared from a particular locale? Have they appeared in places they had not been seen previously? Do their feathers exhibit traces of pesticides or heavy metals? With stuffed birds in museum cabinets we can answer many of these questions. Even DNA can be extracted for evolutionary and taxonomic studies.

Unlike the dioramas of the typical natural history museum that puts animals in realistic poses, the typical bird specimen is a “flat mount” or “study mount”, flat on its back, beak forward, stuffed with cotton. This is to make every specimen comparable to every other one. So if a scientist decides to measure the wing length of every Downy Woodpecker in five different museums, the measurements will be equivalent.

Preparing study skins takes a bit of practice to perfect. Basically, it’s slicing the bird vertically from the thorax to the abdomen and turning the skin inside out. After the body is removed, the skin is rubbed with cornmeal to absorb moisture and then treated with borax (Twenty Mule Team) as a preservative. In the past arsenic was used. John Cassin, famous ornithologist and curator of the ornithology collection at the Philadelphia Academy of Sciences in the mid 19^th century, a time before latex gloves, died of arsenic poisoning from using it to preserve bird skins.

When I first started as a new professor and ornithologist, I inherited a bird collection, which not only housed thousands of bird skins, but two giant upright freezers of dead birds, some of which had been frozen for years. Being pretty much useless as birdcicles, I made study skins out of them.

One slow news day a local newspaper reporter decided to ask how the new ornithologist was doing, so I showed him all the specimens I had prepared. After his article came out, all kinds of people in the community were calling because they had dead birds to donate. Some were road kills, some window kills, and some deceased pets. One woman gave me an albino Western Scrub Jay. Although I was appreciative of that addition to the collection, I had not realized that frequent visits by the donor were part of the deal.

Well, I was never going to stuff everything at the rate birds were accumulating, so I incorporated the preparation of bird skins into my ornithology class. Later I taught a class in museum preparation, not only study skins, but also lifelike taxidermy mounts. I first learned the techniques in a wildlife biology class in college where we used a book of taxidermy methods. It had two sections: Birds and Animals. That phrase irks me to this day. Birds are different than animals? How about Mammals, folks?