Gossamer Tapestry

Reflections on conservation, butterflies, and ecology in the nation's heartland

Monday, June 21, 2010

Indiana Trek

Kirk guides us through Swamp Metalmark habitat at Clover Lick Creek

Earlier this spring the Nature Museum's Butterfly Restoration Project and Susan Borkin of the Milwaukee Public Museum were awarded a small grant from the Butterfly Conservation Initiative. This grant would allow us to visit a population of Swamp Metalmark Butterflies in extreme southern Indiana. The population was reported to be very large. The purpose of our trip was to verify the existence and size of the population, to evaluate the habitat at this site, and to clip small fragments from the wings of a sample of metalmarks for DNA analysis. We would also collect a female to bring back to Chicago for some further experiments on breeding the species in the lab.

Looking for Metalmarks

We were guided in our efforts by Kirk and Jason from the US Forest Service. I don't know what we would have done without them. They guided us right to the appropriate spots, and offered valuable insights into ecological changes (mostly brush advancement).

Male Swamp Metalmark

We were to visits two sites about a half hour apart. At Boone Creek, we found metalmarks almost immediately. They were present in small numbers- we only found about a dozen individuals. We hoped we would do better at Clover Lick, which was reported to have a larger population. In that, we were a bit disappointed. All told, we only found 4 individauls at Clover Lick, and these were scattered over a wide area.

This shows a tiny part of a huge number of butterflies we saw
puddling in a dry stream bed

We were lucky to have gorgeous weather during our visit. The number of butterflies that we saw was amazing- every butterfly milkweed that we came upon was covered with a half dozen swallowtails or Great Spangled Fritillaires. I got lots of nice photos.

Great Spangled Fritillary

The habitat assessment was revealing. Both the butterflies and their host plants appeared to prever edges between open fields and woodland. In these areas, the host plants were in shade for part of the day. We collected data on host plant density, canopy height, as well as population size for the swamp metalmark. I was able to get DNA samples, though not so many as I had hoped for.

Harvesting DNA Fragments

All told, it was a very successful venture. We got lots of environmental data, and now have a single female set up for egg laying in our lab. The population is almost certainly a lot smaller than we expected. That's a disappointment, but it's still very important to know.

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Tuesday, June 08, 2010

A Day for the Ducks at the Notebaert Nature Museum



Friday, June 04, 2010

The Gorgone Checkerspot Comes Home

Gorgone Checkerspot (Chlosyne gorgone)

This project started out here at the Nature Museum nearly a year ago when we attempted to get female Gorgone Checkerspots to breed in the lab. The first week of July, 2009, we got 3 females. They laid a bunch of eggs in the lab and we started raising the caterpillars. Sometime in August they stopped feeding, and in September we put them to bed for the winter. In April we roused them from hibernation, learning in the process some important things about holding butterflies over the winter. We had 94% survival over the winter (!). The larvae have been eating like mad, and pupated about two weeks ago. Yesterday (June 3) we brought about 250 adults out to the Nachusa Grasslands for field release.

Vincent and Robin releasing Gorgone Checkerspots

Nachusa Grasslands is a huge prairie site owned by The Nature Conservancy. It contains perfect dry hill prairie habitat that the Checkerspots require. the caterpillars feed on pale purple coneflower. As you can see in the photograph above, there is ample hostplant on the gravel hills to support a population of this butterfly.

Robin shakin' it

Many of the butterflies needed to be coaxed out of the cage

The butterflies were transported in cylindrical screen-sided cages. They needed to be coaxed out into their new home. Perhaps they knew that they were entering a predator-filled world.

Dot's Knob

Nachusa is a beautiful prairie that covers rolling hills. the drier tops of the hills (or knobs) are the preferred habitat of this species. We released the butterflies on Dot's Know and Doug's Knob- named for two early supporters of Nachusa.

I really hope this was a productive mating

We saw lots of mating- both in the cage and with released butterflies. I hope lots of egg laying follows. It will be another year before we know whether there has been successful reproduction on site. Welcome home Gorgone Checkerspots!

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