Tuesday, May 29, 2007

Spatterdock Darners are back

Rhionaeschna mutata

About 8 years ago, I started looking at the Ode fauna along the Embury Road area in NW Washtenaw Co., MI. That first year, Ethan Bright and I scouted out a small pond on the E side of Embury Rd. that wasn't on any maps, except as a wetland. At that time, the water was about 2 feet deep, and that year, we saw plenty of Rhionaeschna mutata, the Spatterdock darner. It turns out that mutata is predominantly found in fish-less ponds, and this pond was full of spatterdock and fish-less. It also turned out that the pond is an intermittent one, as a few years ago, it was just a muddy wet area with a few tiny puddles of water. So, being an intermittent pond, fish can't survive there --but Odonata certainly can!

Last Friday, I visited the pond and the nearby hillside where the odonata that emerge often go to feed and mature. It was a day with clouds and intermittent rain, but the place was filled with thousands of recently-emerged Nehallenia irene.
Nehalennia irene

Phil Myers from the UMMZ was also with me, and we proceeded to photograph Lestes dryas, N. irene, Celithemis elisa, and Leucorrhinia intacta.

After we were there about an hour, I saw a big darner zip by and fly around in the clearing for a few seconds... it was large, and at first I thought Basiaeschna janata. Then it landed on the trunk of a tree. I crept towards it, hoping that I could get a few shots and figure out what it was. As I got closer it realized it was an immature Spatterdock darner. After I got a few shots, I slowly moved my hand towards her and was able to grab her as a voucher! SO, the good news is that R. mutata is back at the pond, and it now has about a foot of water in it -- but it's still way below what the level was in 1998.

I need to go back on a sunny day this week and see what else is flying!

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