Again with the Swamp Metalmarks?
I’ve been having a lot of field time of late. We currently have six different species of butterflies that we are breeding in the lab as part of our restoration efforts. I just came from the lab and we have tons of egg production from most species.
Colleagues and I ventured up behind the Cheddar Curtain yesterday. Our goal was to get swamp metalmark females for egg laying. I haven’t talked much about the metalmarks lately. They are the most significantly endangered species we are working with. They had been extirpated from Illinois. We now have a tiny restored population here, but it's insufficient to carry the species in Illinois for the long run.
The underside of the metalmark is really hard to photograph, but I wanted to show the beautiful yellow color.
Although we made significant progress last year and over the winter, we were ultimately unsuccessful in our efforts. Thingfish23 recently wondered if I shared my failures on the blog. Yup, I do. This one was particularly painful.
Two tiny larvae from August 2007
The metalmark larvae survived the entire winter, continuing to eat, grow, and shed their skins. Starting in late March, we began to experience larval death. It wasn’t a lot at any one time, but here and there, they would just dwindle in numbers. None of them pupated- it was as if they had simply died of old age. Curious. Somehow, we had failed to provide them with an appropriate environmental cue to complete their development.
This year, we will proceed more carefully. We will pay close attention to photoperiod. We will allow at least part of our larval population to over winter in cages outdoors where they can experience low temperatures. But we are trying again, and that’s where yesterday’s trip came in.
We met Su up at one of the know metalmark sites in east central Wisconsin. Su works for the Milwaukee Public Museum and has been doing swamp metalmark restoration in Wisconsin for some time now. The site is a fen- an alkaline, springy area, with lots of sedges and swamp thistle- the caterpillar food plant. There was also a lot of both poison ivy and poison sumac, which caused me to think of Homer, who, no doubt, is glad he wasn’t with us.
It was dim and cloudy the wole time we were at the site. Hence the really mediocre photos (sorry). In spite of the weather, we were pleased to find a robust population of swamp metalmarks this year. We managed to get four very fat females, who are all now producing lots of eggs. Yay. This is proving to be a difficult species to work with- but, as I have mentioned before, the species is in real trouble. There are now rumblings about gathering additional status information for the species. This may represent the earliest stages of moving towards a federal listing process.
I’m optimistic about the future for this species. I don’t have good reason to be, but I must. I refuse to consider the alternative.