Tom Peterson, Fermilab's Butterfly Expert

Butterfly Home Tom's Tools Contact Tom

Meet Tom Peterson!

Butterfly Watching
Like many avid butterfly watchers, Tom's interest started at an early age, when he was about 8-years-old. While in grade school, Tom spent nearly every summer day roaming a nearby railroad and creek shoreline with his brother, in search of insects. He learned to catch and mount the different species for display.

By the time he reached high school, Tom had stopped collecting specimens, but he was still very interested in insects--especially butterflies. So he started just watching butterflies like a birder watches birds. He also kept a cage in which caterpillars went through their transformation to butterfly (or moth). The process of metamorphosis--from the worm-like caterpillar to the graceful butterfly (in as little as one week!)--has always amazed Tom. He can remember getting very excited when his first giant silk moth, a Luna moth, emerged from a cocoon that he had found.

Butterflies are fascinating as well as beautiful insects, and Tom has learned a lot about them in his years as a butterfly fan. When he began his hobby, there were few books that could teach anyone a lot about butterflies. Tom realized that just by watching and paying attention, he could learn almost as much as any field guide could tell him.

Just patiently following and watching butterflies may seem a little strange, but the rich colors and intricate patterns on butterfly wings are best viewed up close. Although butterflies often seem very timid, it is surprising how often one can get very close, even close enough to coax the butterfly onto one's finger!


Get Involved!
Tom is not a professional butterfly-watcher--he's actually an engineer here at Fermilab, but that doesn't mean he doesn't feel involved with the butterfly world. Aside from the pleasure of finding and watching these beautiful insects, observations that amateurs make can really add to the general understanding about butterflies. For example, keeping records of observations can tell scientists more about when and where the adult butterflies appear, how many generations there are per summer, how the butterflies spend the winter, and the impact of human activities on their populations. Also, some butterfly species are good "indicator species," which means that their presence (or absence) can tell us about the quality of a natural area.

Tom is also part of an organization called the Northern Illinois Butterfly Monitoring Network. This group connects volunteers who want to help keep track of butterflies. Anyone who wants to be involved can do so. The Network trains monitors and there isn't a big time commitment or a lot of pressure.


Here at Fermilab
One of the best ways to begin learning about butterflies is just get out and look for them. Fermilab is a great place to start. Searching the out-of-the-way places at Fermilab is like exploring a new territory. It is exciting to find unusual butterflies that you can't find in a suburban back yard.

A good place to see a variety of butterflies at Fermilab is the Interpretive Trail (starting at the parking lot across Pine Street from the Education Center) from late June through August. For example, the Great Spangled Fritillary favors the woods/prairie edge where the Prairie Trail nears the Big Woods. These large, black and orange butterflies with shiny silver spots on the underside of the hind wings fly from late June into August. A butterfly which lives in old fields but has found a home in our prairie restorations, probably feeding as a caterpillar on Big Bluestem grass, is the Common Wood Nymph. Brown with two large eyespots on the each front wing, it flits through the tall grass with a funny, low, bouncing flight. A close relative, the Pearly Eye, may be found just a short distance away in the woods.

If you would like more information about Fermilab butterflies, or are interested in getting involved in butterfly watching, please feel free to contact Tom at He would be glad to answer questions and help get you started.

Read an article about Tom from FermiNews.