Tuesday, September 28, 2010

Two Meadowhawks

Over the weekend, Jon Quist and I made our way to the small and secluded Fish Creek drainage just north of Kerckhoff Lake in Madera County (California). There is no easy access to the creek and it's narrow valley - only a difficult dirt road and dusty trails lined with cow patties. Gray pines and oak trees provided shade but the grass was sere and the day was warm. Kerckhoff Lake, after all, is still pretty much a valley lake though nestled in the foothills above Fresno - with an elevation of just under 1,000 feet above sea level.

But Fish Creek itself was full of water and near the lake it was backed-up with cattails and blackberries growing along the margin. There were also a lot of dragonflies flying about - including two kinds of meadowhawks: the striped meadowhawk (Sympetrum pallipes) and the variegated meadowhawk (Sympetrum corruptum). Both are late summer/fall species with attractive red markings along the thorax and abdomen. They are medium-sized dragonflies and quite striking.

The two species are fairly easy to tell apart - at least the males are. Striped meadowhawks have distinct stripes on the side of the thorax and the dorsal side of the abdomen is predominantly red. Variegated meadowhawks on the other hand may have stripes on the side of the thorax but they also have a more distinct spot at the base of the stripes. More noticeable is that the abdomen is ringed with red, white and gray markings. The forewing also has a pale reddish pink color in some individuals.

We found the striped meadowhawks mating and laying eggs by the stream. They go about things a bit different than most other dragonflies that drop their eggs directly into the water. The meadowhawks remained in copula with both male and female "bouncing" up and down above the moist grass near the creek, with the female dropping eggs into the grass. The timing is quite appropriate as the fall rains are due in just a month or two and the stream bank should be at least a few inches higher than it currently is - flooding the area where the eggs are resting.

The variegated meadowhawk is known to be a migratory species making its way from Mexico north into the US in the spring. Individuals in the US are also known to fly north into Canada in the spring. I'm not sure where these individuals from Madera County will go but more than likely, they'll complete their life-cycle right here in Central California where we only get a few light frosts each year.

The picture of Jon wading in the water is a habitat shot where both species were flying.

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