Butterfly Release

Silver-bordered Fritillary (Boloria selene)

Well, it finally happened. After bacterial outbreaks, a very low population at the donor site in 2006, a trip to Florida by a member of my lab for pointers in breeding butterflies in captivity, and some unexpectedly violent weather last week, we released Silver-bordered Fritillaries at Glacial Park on Monday. The poor performance of the species in 2006 was particularly difficult. We went out five times before we finally managed to collect gravid females last September. This was right at the end of the flight period and left no room for problems (which we, of course, had). This year, we managed to collect our breeding stock in mid July, and things have gone very well ever since. The early start was one of the reasons that last week’s thunderstorm delay did not concern me overly- we still have plenty of time for additional releases this season.

Releasing the butterflies at Glacial Park
L-R: Janice, Vincent, Dawson

After all of the buildup and false starts, the release itself was surprisingly uneventful. True, the mosquitoes continue to make things somewhat unpleasant at the moment. But the weather was lovely and it’s always great to be able to do some of my work in the kind of beautiful surroundings that we were in on Monday afternoon. Glacial Park is part of the McHenry County forest preserve system. It’s a huge site, with lots of potential habitat for this particular species of butterflies. So if a population successfully takes hold it has the potential to become fairly large.

Vincent and I look on as 2 newly-placed butterflies warm up.

On Monday, the adult butterflies were chilled in the refrigerator, placed in about a dozen small containers, and packed on ice in a cooler. When we got them out to the release site, they were nice and cool (read: inactive) and we could easily place them on plants. We released 90 individuals. They slowly warmed up and became active. My one concern was that the butterflies would warm up and then rapidly leave the area- but that’s not what we observed. As they warmed, they circled around in the large field we were in. They would land on flowers, and several were observed actively nectaring. It was so rewarding to see this beautiful species checking out its new home. I’m hoping that a lot of them mated yesterday and today. If successful, the females will spend the next week or so laying eggs. Think fertile thoughts!

Janice, me, and Vincent with a cooler of exotically-packaged DNA

So what’s next for this project? A bunch of stuff. We didn’t release all of our adults. Some in the lab have already begun mating and laying eggs. We hope to get a second generation of adults, and will attempt additional releases next month. We may even release at a second site. We are still working with other species such as the swamp metalmark. We still have over 80 caterpillars in the lab. Next month, we will obtain the beautiful and endangered Regal Fritillary for egg collection. We will field release some caterpillars in October, shortly after they hatch. The remainder will be released next season.

The Silver-bordered Fritillary Team
L-R: Vincent, me (both from the Nature Museum),
Janice and Marla (both from McHenry County College)