Wednesday, July 20, 2016

Rambur's Forktail - Wheel

In summertime birding slows down while we await the returning shorebirds, but hopefully we still get to enjoy the species that breed in our area. The warm days may not be ideal for birding, but the dragonflies love it, and many birders take time to look for them near creeks and ponds.

Ishnura is the genus of the Forktails. Of the 14 forktail species seen in the U.S. 8 can be found in California. I think the mating pair here are an example of Rambur's Forktail, Ishnura ramburii. It''s range barely includes southeast California, but is a common across the southern tier of the U.S, including this twosome we found in Palm Harbor, Florida, early April 2016..


The male (above) is clasping the female behind her head, while she bends her abdomen sharply forward to receive sperm from where they have been stored in his second abdominal segment. This "ring", or "wheel" position is seen in many species of damselflies and dragonflies during mating.. Note how the coloration of the female here strongly mirrors that of the male, a color phase describe as "andromorphic". Andromorph females are supposed to be pretty common among Rambur's Forktails.

There are 69 species of forktails worldwide (Paulson, Dragonflies and Damselflies of the West). Many have largely black abdomens when viewed from above, often with blue in the last few abdominal segments.

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