Where last we left off I was explaining my plan to look at butterflies held in museum collections in order to compare them to field caught butterflies. To this end, I spent a week in November in this nation’s capitol. Behind the scenes! At the SMITHSONIAN Museum of Natural History! For some reason, this whole endeavor was super exciting to me… On my drive to DC I was having visions of Ben Stiller’s “Night at the Museum” where exhibits were coming to life and I was running away from dinosaurs. All I knew is that they had about 500 specimens in the collection that were relevant to my study and they were giving me a “no-escort” badge so I could come and go as I pleased.
While being at the museums and seeing the collection is exciting, processing museum animals is more tedious than riveting. Walking into the entomology department at Smithsonian looks like row after row of non-descript metal closets.
They showed me the Colias cabinet and opened the drawers.
This is my little set up at the museum:
To make direct comparisons to field collected specimens, I need to take the same exact measurements on the preserved specimens. This includes: measuring body length, wing length, and taking photos of the wings to estimate how dark they are. In live specimens, this is pretty straight forward. I place the bug between two pieces of plexiglass (one of which is buffered with bubble wrap) then I can measure it, and photograph it no problem. With the museum specimens, they pinned with the relevant information written on a tiny piece of paper and impaled just below the bug. So to measure and photograph these guys, I have to remove the piece of paper, flip the bug over so that the underside is exposed to the camera, and use microcalipers to measure (without touching) the animal.
First I take off all of the papers and then record the information. Then I measure each one. Then I photograph them. Then I reattach the paper and place them back in the museum drawer. The oldest specimen that I processed was from 1892!
Despite my working late, nothing came to life during my visit to the museum.
My name is Heidi. I am long-time reader, first time blogger here on Butterflies and Science. Jessica and I have been collaborating on the Colorado Colias work for the last few years now. While Jessica gets to play with the cute caterpillars, I chase the adults around and try to figure out how they are responding to the increasing temperatures at high elevations in the Rocky Mountains.
Because our lab (http://www.unc.edu/~lbuckley/lab/pmwiki.php) is primarily concerned with how organisms are responding to climate change via morphology, physiology, and life history, I think a lot about evolutionary responses to environmental pressures. One of the best examples of this comes from the industrial revolution. The peppered moth is endemic to the British Iles survives as an adult by being a twig mimic. While there have always been two main color morphs of these moths (a lighter and a darker one), the lighter morphs historically survived in greater numbers as their speckled pattern helped them blend in with the lichen on the tree bark and avoid. During the industrial revolution, pollution in the form of soot settled out of the atmosphere in the canopy of the trees and washed down the bark during rainstorms killing the lichen that covered the bark. This effectively darkened the bark which, in turn, created an environment that was more hospitable for the darker morphs where as the lighter morphs stuck out like a sore thumb and were quickly gobbled up by their avian predators.
While greenhouse gasses are not as easy to see as industrial soot and the evolutionary response to atmospheric warming may not be as immediate, clear examples of how species are responding to warming are needed to inspire reform. Our work with the high elevation species of Colias meadii holds the potential to do just that. By tracking traits in the field (specifically wing melanin which determines how quickly these guys can heat up and fly) and comparing current populations to museum specimens, I am hoping to be able to detect a change in mean trait value over time in response to warming. Below is a schematic of the area of the wing we are looking at.
Congratulations CarolinaSarah on your award winning blog post!