Monday, 16 September 2013

Comet Darner from Brantford

Earlier this year, Bill Lamond found a few Comet Darners at a pond in Brantford. So one weekend back in July when I was back home Ken, Erica and I decided to check it and weren't disappointed.  The pond didn't look like much (it is a drainage pond less than 1/2 hectare in size in an industrial park), but it was absolutely teeming with dragonflies.  When we arrived there were hundreds of Black Saddlebags, Widow Skimmers, Twelve-spotted Skimmers and Familiar Bluets (amongst a few other species) but it didn't take us long to find our target:

Comet Darners are historically very rare in Ontario, typically being found only to our south. In fact, when the current Ontario Odonata Atlas species maps were done up in the early 2000s the map for Comet Darner had only 2 records on it! However, in the last several years we have seen an increasing number of records, still all from southern Ontario where migrants are more expected.  It is hard to know for sure whether the increase in records is real or just an artifact of the greatly increased search effort by the growing number of dragonfly enthusiasts in Ontario.  Realistically, it is probably a combination of those two factors.

The Brantford record is especially intriguing because Bill also found Comet Darner at this location last year, which may suggest that the species successfully overwintered at the site - something that hasn't been demonstrated yet for Ontario.  We did a quick search of the shoreline for exuviae but were unsuccessful in finding any.  Of course, with the abundance of other migrant species at the site, maybe it is just the perfect spot for migrant species to drop in to...

This species is similar to the familiar Common Green Darner, but the red abdomen is really distinct.  Another easy field mark is the patterning of the postfrons (think of it as the top of the 'nose') - on Common Green Darner there is a "bulls-eye" pattern, while Comet Darner is plain:
Top view of head and postfrons of Comet Darner
Top view of head and postfrons of Common Green Darner
If you are at all interested in Odonata in Ontario, be sure to check out the Ont-Odes google group and submit your sightings to the Ontario atlas (details here).  There is also a course being offered at Long Point Bird Observatory at the end of the month that you might be interested in!


  1. That last picture is unreal! I think I must start learning about these creatures.

  2. At the Townsend Sewage Lagoons a couple of weeks ago there were thousands (literally) of Familiar Bluets.