Thursday, March 31, 2011

The Pacific Northwest's First Fliers

Usually around mid-February my mind becomes occupied with thoughts of when the weather will turn sunny and warm enough to bring out flying odonates in my area (Vancouver, Washington). My general rule-of-thumb conditions for the first flying odonates of the spring are about three consecutive days of around 60° F or more and at least partially sunny skies. Of course, a few odonates could be flying before those conditions are met, but it’s what I look for before I start thinking, “There must be something flying now.”

This year, unfortunately, the spring weather has been unusually cool and wet—just across the Columbia River from me, Portland, Oregon has broken its latest first 60° (F) day record (which still has not been attained as of this writing) and its number of March days with measurable rainfall record (currently 28 days). This has been a tough spring for me.

Saturday, March 26, 2011

Just a Photo: Pacific Forktail (Ischnura cervula)

A male Pacific Forktail (Ischnura cervula) in Albany, Oregon. This very common and widespread species is
one of the first to start flying in the Pacific Northwest. This spring has been uncharacteristically cool and
wet, but they should be out any time now as soon as we get a few warmer, sunnier days (at least where
 I am in southwest Washington—it could be a few more weeks further north).

Wednesday, March 16, 2011

Somebody Lost Her Head

A few weeks ago an odonatist friend made a general request of photographers to look through their photos and see how frequently adult dragonflies other than libellulids (skimmers) are hosts for water mites. When you spend a lot of time looking at odonates, it becomes clear that certain groups (like several libellulid genera and a variety of damselfly genera) are frequent water mite hosts, while other dragonflies in non-libellulid families and some libellulid genera rarely host water mites even if they breed in aquatic habitat that is suitable for mites. The subject of water mites is an interesting one and I’ll write more about them another time, but all of this leads me to the real subject of this post...

So, I was scanning through my dragonfly photo collection looking for water mite carriers, when I came across a male Diminutive Clubtail (Gomphus diminutus) that I photographed in South Carolina a few years ago. I noticed that it had a reddish-brown, bulbous thing on one of its front legs which looked superficially like a water mite except that it was too big and legs are a strange place for a water mite to make its temporary home (typically they attach to the lower areas of the thorax and abdomen). I decided that it wasn’t a mite, but I couldn’t really tell what it was.