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BIG CALIFORNIA DRAGONS
My wife Rita and I are birders. In June 2006 we knew nothing about dragonflies. Yet there is something about a hot summer afternoon, when birds are few but dragonflies are buzzing, that turns one's attention to these marvelous insects in the order Odonata (often called "odes" or "odonates"). It was during a tour through the foothills of northern California that these dragons first caught our attention.

The single dragonfly that first sparked an interest is this one (right & below). It seemed to dominate a little reedy pond north of Chico, Butte County, on 20 July 2006. Using Tim Manolis's 2003 book Dragonflies and Damselflies of California, we tentatively identified it as "Comanche Skimmer  Libellula comanche.," and thus made our first dragonfly identification mistake. Swing-and-a-miss; strike one. [I would strike out several times in subsequent months.]

Ray Bruun, who has an incredible set of dragonfly photos from northern California, suggested the correct answer: Blue Dasher  Pachydiplax longipennis. It seemed big as dragonflies go it is listed at 1.5 inches long and 2.5 inches in wingspan (but there are bigger ones). In the photo below, note the clear wings (we can see right through them) with a cream-colored pterostigma [that small opaque patch near the leading edge of the wingtip on the near wing; Comanche Skimmer actually has a strikingly two-tone black-and-white pterostigma]; the bluish pruinescence (a powdery substance) on top of the abdomen but striped below (right); and the green eyes with a white face.

It is perched in an "obelisk" position, pointing the tip of the abdomen towards the sun as a thermoregulation device (Manolis 2003).

We would run into the Blue Dasher again, this time holding a more typical perched position with the wings held forward and down (right), a couple weeks later in Monterey County. This time the male was on a small stock pond at Hastings Natural History Reservation in upper Carmel Valley. This is a widespread species in the U.S. and southern Canada. Manolis (2003) says that "Blue Dashers actively sally for small prey, returning repeatedly to the same perch after making a capture. They look very alert on perch, seeming to lean forward with the abdomen cocked up and the wings swept forward or up and back. Males occupy low perches over or near water and, where densities are high, engage in frequent territorial skirmishes for preferred sites."
Another very impressive, large dragonfly encountered that same trip through northern California was this Widow Skimmer  Libellula luctuosa. This is a widespread dragon across the United States but has apparently expanded into northern California within the last century (Manolis 2003). It like artificial bodies of water this one was among many on a farm stock pond in Glenn County, just north of Stonyford (Colusa Co.) on 18 June 2006. Each male was busily defending a patch of emergent reeds.
The final 'big dragon' we ran into on our June 2006 trip up north was Common Whitetail Plathemis lydia [sometimes called White-tailed Skimmer], above and right. We found many males defending little territories around the edges of the Hayfork sewage ponds, Trinity County, on 19 June. It is a black-and-white-winged skimmer, like the previous species, but note that the distribution of black-and-white is very different. The English name comes from the chalky white pruinescence on the abdomen. According to Manolis (2003), it is "one of the most familiar and widely distributed dragonflies in the United States."

Rita and I learned several weeks later that Walt Koenig had studied this species at Hastings Natural History Reservation in upper Carmel Valley, Monterey County (see Koenig & Albano 1987). On 1 July we joined Walt to a favored pond and watched males defend territories by constantly patrolling them, and chase any female that came into a territory for a brief mating session on the wing. The female then immediately dips down to the water surface and thrusts in her abdomen to lay eggs while the male defends the air above her from other males wishing to mate that very instant. It makes for a a very dramatic moment at the otherwise quiet little pond.

TO NEXT PAGE OF "DRAGONFLY JOURNAL"
There are some very nice web pages featuring dragonflies. Some of those that focus on California are: And for a broader spectrum of North American odonates:

Literature cited:
Koenig, W.D., and S.S. Albano. 1987. Lifetime reproductive success, selection, and the opportunity for selection in the white-tailed skimmer Plathemis lydia (Odonata: Libellulidae). Evolution 41: 22-36.

Manolis, T. 2003. Dragonflies and Damselflies of California. Calif. Natural Hist. Guide 72. Univ. of Calif., Berkeley, CA.


PHOTOS: All photos are © 2006 Don Roberson; all rights reserved.

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