Rhionaeshna californica

California Darner is a widespread darner from British Columbia to Baja (Manolis 2003). Until 2007, there was but one MTY record: the one shown above, at the Carmel River mouth on 7 July 2006. What is more remarkable about the story is that this was the very first darner that I ever found perched in MTY; it is my very first darner photographed in MTY; and at the time I assumed it was a Blue-eyed Darner. I actually found and photographed a perched Blue-eyed Darner about a half-hour later on the same date and place (that photo is below). I didn't realize that two species were involved until examining the photographs side-by-side later that week.
first three photos this page 7 July 2006 Carmel River mouth
These two shots provide a side-by-side comparison of male California Darner (left) and male Blue-eyed Darner (right).
 Points to compare include:
  • California Darner is slimmer and does not have the 'chunky' thorax of Blue-eyed
  • California Darner lacks short blue stripes on top of the thorax which are shown by Blue-eyed
  • the eyes of California Darner are darker gray-blue than the sky-blue eyes of Blue-eyed
  • the twin blue dots on the final abdominal segment are close together, almost touching, on California; these are widely separated on Blue-eyed
  • the terminal appendages are quite different: California has a single cerci [better seen in the photo at top of this page] while Blue-eyed has cerci that are forked, with the upper fork longer than the bottom fork [best shown on the Blue-eyed Darner page, or in Manolis 2003]
In 2007, knowing that California Darner was the first darner of the spring in much of California, I went looking for it in March. Starting on 18 March 2007, I saw small dark mosaic darners in flight almost daily at Carmel R. mouth but was unable to confirm identification until I managed a flight shot on 23 March (right; lack of stripes atop the thorax among other things).

A few weeks later (3 Apr) I managed this flight shot at Laguna Grande park in Seaside. Note again the unmarked brown back, the simple cerci, the position of the final blue dot on the abdomen, and the darkish-blue eyes (not bright blue).

On 26 March another male at Laguna Grande park that perched nicely for photos (below).

California Darner averages decidedly smaller than other MTY mosaic darners, and has a shorter abdomen (ratio of thorax:abdomen is about 2:1; about 3:1 in other similar species). These proportions can be seen in flight, given decent views, and it always looks small and dark. All the features mentioned above apply to these photos (above & below). On the second shot below, note the little tubercle on the underside of abdominal segment 1 that identifies this darner as a member of the genus Rhionaeshna.
Females are seen much less often. Steve Rovell found this teneral darner fluttering in trail-side grass at Frog Pond Nature Area, Del Rey Oaks, on 4 Apr (below). It is brown and yellow, like a female (although I do not know what teneral males are like). Points to notice include the unmarked brown back, brown pterostigma, the shape of the front side stripe (tapers to a point at the upper end), the black line across the face, and the very broad shaft and 'legs' to the 'T-spot' at the top of the face and in front of the eyes.
The map shows the some locales from which California Darner is currently known. We expect it will be found elsewhere, and perhaps widely. Sites range from coastal marshes and ponds (Carmel R. mouth, Laguna Grande, Moonglow Dairy) to foothill rivers (Arroyo Seco & upper San Antonio).

MTY flight dates range from 18 March to 7 July. Elsewhere in California, the flight season is March into August (Manolis 2003).

I've shown many shots of California Darner, but here is the first one reproduced again, at full-frame, so you can see the habitat in which the darner was perched. Note how hard it can be to spot a perched darner before it flies.

Literature cited:
  • Manolis, T. 2003. Dragonflies and Damselflies of California. Univ. of Calif. Press, Berkeley.
Web resources:
Major identification web sites with much information on California odes include: For sites with excellent photos to compare for identification or to simply enjoy, see: Many of these sites have links to other useful pages. Kathy Biggs's site is particularly useful in her selection of links.

All photos © Don Roberson 2007, except the teneral © Steve Rovell, used with permission


Page created 9 Oct 2006, revised 5 Apr 2007