Ischnura perparva
Western Forktail is a common and widespread species — both throughout California and in Monterey County — but it is still somewhat elusive, at least to beginners. It is very small (1 inch), flies only short distances, and has a bewildering assortment of immature and female patterns that can sometimes make identification intractable.
Photo (above) 30 July 2006 Lopez Cyn, just W of Pinnacles NM
Photo (below) 2 Aug 2006 Laguna Grande
Male Western Forktail (above & below) are lovely creatures patterned in black and aqua-blue. There is a prominent colored stripe between the top and side black stripes on the thorax; two small colored 'eye-spots' and another spot between those atop the head; and an extensive blue patch atop abdominal segments 8 and 9 and a bit of 10, connected (usually) to blue below these segments. Some males seem a bit more green (above) while others are more blue (below). They can also be identified in-hand by their terminal appendages (see Manolis 2003).

Females (above & left) are much more complicated. They start out orange but turn pale green as they age, but also with age a grayish-blue pruinescense covers the entire abdomen and upper thorax, obscuring the color. Many end up with all sky blue-grayish abdomens. All female Western Forktails have a relatively stout abdomen — compared with Pacific or Black-fronted — but this is a subtle character learned with practice. I certainly messed up the i.d. of many my first year. Older Pacifics also get pruinose.

One usually finds more Pacifics than Westerns, so perhaps the first question should be: why isn't this a Pacific? Stigma color, which has been cited as a field mark, is not consistent [see Pacific Forktail page] although Westerns average darker stigma.

Photo (above full frame) 21 Oct 2006 Lake San Antonio
Photos (above left) 5 Aug 2006 Arroyo Seco

The map shows a selection of locales at which Western Forktail has been found. It is widespread in the lowlands and into the Santa Lucia foothills. It is found around still, shallow water: pond edges, grassy wet meadows, seeps, trickles.

This species has a long flight season from March to November (Manolis 2003). In MTY the records so far range from 29 March–21 October.

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. Special thanks to Dennis Paulson for correcting some initial identification mistakes!


Page created 18-27 Mar 2007