17 June 2012

Blue Eyes are Flying

After completing my Breeding Bird Survey (BBS) route on June 9th, I decided to stop by Munson Park in Monroe, MI in hopes of finding an interesting dragonfly or two.  I was also wanting to collect a Common Green Darner (Anax junius) for the stable isotope project.

This park is unique in that it provides a small oasis in an area (and county) surrounded by highly manipulated land.  Through the years we've found a wide variety of fauna that can be difficult to observe, from birds such as Grasshopper and Henslow's Sparrows to many first county record dragonflies such as river cruisers (Macromia illinoiensis and taeniolata), Swamp Darner (Epiaeschna heros), Great Blue Skimmer (Libellula vibrans), and Citrine Forktail (Ischnura hastata).  On one occasion, I also observed a female Mocha Emerald (Somatochlora linearis). Water features (except some small ponds, agricultural ditches, and the River Raisin) supporting the diversity aren't fully evident, but there must be some variety of sufficient water quality nearby.

The day's westerly winds had increased by the time I arrived.  Thus, I wanted to check out the NE area of the park which would be sheltered by the woods and treelines.  Immediately I found darners and baskettails working the hedgerow.  One large baskettail had wing markings that were reduced.  Around here, Prince Baskettails (Epitheca princeps) typically have markings that make ID from a distance very easy.

A quick swing of the net produced this male:

Here is a photo showing the typical markings for E. princeps in SE MI:

Apparently, some populations further north will have little to no markings in the middle of the wings.

In the past, I've found the path between the prairie plantings and the woodlots to be quite productive.  The mowed area functions as a highway for the larger dragonflies such as this male Common Green Darner (Anax junius):

The width and length of the path makes it convenient to see individuals flying towards you or when flushed from perches in the trees or grass.  Within several meters a darner flew towards me at head height and I couldn't make out the species, but had assumed it to be another A. junius, until the blue eyes became apparent only a few feet away.  A lame swing over my shoulder missed this new county record. Knowing other people had observed multiple individuals in other locations of southeast Michigan this spring, I was hoping to have a chance at a second one.

Upon approaching the northern end of the path, I saw a darner rounding the corner and flying towards me at waist height.  I attempted to squat down to have a better view, and indeed, it was another Spatterdock Darner (Rhionaeschna mutata).  However, instead of flying past me, it flew towards me and jammed my possibilities to catch it in the net. (If only I had a shorter-handled net for that one!)

Eventually, a third individual was captured as it flew down the path at chest height.  Here is a male Spatterdock Darner (R. mutata) which is the first Monroe County record:

Later I was able to pose a second Spatterdock (R. mutata):

This species was quite a surprise.  As noted, I'm not sure of the location of the water feature for these to breed (fishless ponds with lilies), but there must be more species to find in and around this park... and we know there are Mocha Emeralds (S. linearis) still to be captured.

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