This seems to be the year to keep an eye out for unusual species in the northern states.
In the previous post about the Band-winged Dragonlet (Erythrodiplax umbrata), we noted recent observations by others of Double-ringed Pennant (Celithemis verna) in Jackson County, Michigan, and Golden-winged Skimmers (Libellula auripennis) and a Little Blue Dragonlet (Erythrodiplax miniscula) near Toledo, Ohio. Recently, there was also a Great Pondhawk (Erythemis vesiculosa) in Minnesota and a Flame Skimmer (Libellula saturata) in Wisconsin.
Since then, a number of Great Blue Skimmers (Libellula vibrans) were noted in Wisconsin and other states in the northeast. We vouchered the first Great Blue Skimmer for Michigan in Wayne County in 2005 (blog post here and paper here). We have had them elsewhere in Wayne County, and also in Monroe County. Julie saw one in the wet woods on our property in Washtenaw County in 2019 but wasn't able to net or photograph it.
On June 21st, I took my net on my lunchtime walk into our woods in hopes of finding L. vibrans. Immediately, upon arriving at the wet woods, I saw two males fighting in a sunlit area next to the path. However, they flew towards the middle, deeper water area of the Buttonbush swamp.
|Wet woods and Buttonbush swamp
|Male Great Blue Skimmer
No need for the waders or the other net. This was a first voucher for Washtenaw County and the third Michigan county to have the species added to the official list.
On June 22nd, we both went out to our swamp and counted a minimum of 8 individuals, and we couldn't see the entire area at any point in time! All were males; one has to wonder how this many presumably unrelated insects find this specific habitat type -- in a small area -- after dispersing from further south.
Today, June 25th, I decided to search in Tecumseh at Indian Crossing Trails Park since there is potential for a few new species in the county. I spied a Cyrano Darner (Nasiaeschna pentacantha) below the mill race dam, but it stayed in the middle of the waterway (as they usually do). I then began checking some seeps and wet areas in the middle of the park as I've wondered if they could harbor spiketails (Cordulegaster sp.). Again, no luck, but then moved up from the seep area to the wet woods.
To my surprise, there was a flurry of activity with multiple Great Blue Skimmers flitting about in the dappled sunlight. Working my way around the muck while taking on the black mess in my boots, I was able to snag one. I then counted at least 10 other individuals!
|Male Great Blue Skimmer
This wooded wetland was typical of areas where I've found this species, but it was clearly drying up due to lack of rain. The males sit in the exposed twigs in the sunlight.
|~wet woods in Indian Crossing Trails Park, Tecumseh, MI
Lenawee County is now the 4th Michigan County with a vouchered specimen of L. vibrans.
I would have to expect that Great Blue Skimmers could be found across southern MI this year. Look for wooded ponds with dappled light and some open water (i.e. not engulfed by algae or other vegetation). How many more counties can be added with sightings and vouchers?
We'll also need to be checking open ponds for southern species.
Update: on 6/28/2022, I had a Band-winged Dragonlet (E. umbrata) fly by me while at Crystal Waters SGA in Monroe County.