We have an ibis mummy in the lab, which is revealing itself to us in an unusual way.
Unlike most animal mummies in our collection, we can actually see the ibis’ remains – in this case, its feathers! It is unfortunate that the linen wrappings were damaged in the past, but this damage does provide a unique look under the bandages.
Ibis mummy, 97-121-19, from Thebes, Late Period (ca. 664-332 BCE).
While x-ray radiography revealed that there is indeed an ibis inside (the beak is a dead giveaway), the feathers provide further clues about this bird that was mummified approximately 2500 years ago.
Radiograph taken from the top down. Exposure information: 35kV, 5mA, 6 seconds. Image enhanced with flash! filter.
When researching ibis mummies, I read again and again about the African Sacred ibis (Threskiornis aethiopicus) being mummified, but there were other types of ibis in Egypt, including the Glossy ibis (Plegadis falcinellus) and the Northern Bald ibis (Geronticus eremita). I don’t know if evidence has been found that these other types of ibis were mummified, but I do know that I shouldn’t immediately assume that this particular ibis mummy contains the remains of an African Sacred ibis.
So, let’s look at the feathers, and what we can learn from them. The feathers that are exposed appear to be contour feathers that may be part of one of the wings. There are a few completely detached feather fragments in this area, so I was able to take a closer look at one small fragment under the microscope.
Left: ibis feather 7.5X magnification. Right: ibis feather 50X magnification.
The most obvious feature to note, even without a microscope, is the coloration. This feather is white and black. The African Sacred ibis has a very beautiful, distinctive, black and white plumage, so in this case the color alone may be enough to identify species.
If we can’t rely on color, what else can we learn from this feather fragment? Well, we can see that it is part of a pennaceous (rather than plumulaceous, or downy) feather, the parts of which I’ve labeled in the above images. To take an even closer look at these elements, I used our polarizing light microscope and was able to see the tiny hooklets on the barbules, which “zip” the barbules, and therefore the barbs, together.
Ibis feather 100X magnification.
The barbules of feathers can be used for identification of species, but usually barbules from plumulaceous feathers are used, as they have a very different and distinct appearance. Unfortunately, I don’t have access to any plumulaceous feathers from this ibis mummy, so this may be as far as I can go at the moment. There are other researchers, both within the field of Egyptology, but mostly in ornithology, who have spent much more time looking at ibis feather structure than I have, and of course there is DNA research, so we may learn more in the future about this ibis mummy and its feathers.
I have a special place in my heart for birds and feathers, since before coming to the Penn Museum, I worked on an extensive project on feather coloration as part of a collaborative research effort between UCLA and the Getty Conservation Institute. Click on the links below to find out more about this work:
A Collaborative Study of California Featherwork
California Featherwork: Considerations for Examination and Preservation
And to learn more about feather structure, start by following this link: The Cornell Lab of Ornithology: All About Birds: Feather Structure