Thursday, 21 July 2011

A Return to Banded Country and a Great Ruddy Surprise - Part II

So on to Far Pasture . . .
Plenty of damsels front of hide . . . . and my first darter. Just out of range to confirm ID but I presume Common, an immature male on the kingfisher perch, then two flying the pond further out, and a mating pair coming in and out of view through thickish vegetation. I tried to get a focus on them through the occasional gap and reeled off a series of snaps, then the immature male settled for a better view further up the perch and I got him too. A couple of four-spotted chasers still around too, but with time knocking on and thundery clouds approaching I decided to call it a day, pleased with the days sightings.
Back at DragonHunter HQ I uploaded my photos, the immature male darter has a club-shaped tail I hadn‘t noticed at the time. I consult the field guide and discover he‘s not a Common Darter at all but a Ruddy. Bonus!

The two species are quite similar, especially if you don’t see them well and like me, don’t yet have your eye in early in the season (the finer ID points need to be reaffirmed with early sightings I find).
The (mature) males both have a red abdomen, though the ruddy is a lot richer than the more orangey and variable Common. In profile they both appear to have a club-like tail end which confuses, but viewed from the top the Common Darter has more or less parallel sides, slightly tapering towards the tip whereas the Ruddy has a pinched in middle still giving a bulged out look to the tail end.
Another good point of ID is the thorax of the Common Darter has two diagonal yellow panels each side, the Ruddy is a more uniform, brown-red, but of course on this yellowish immature specimen, the thorax appears to have yellow stripes but these will fade with age. And if you get a good look at the legs, Common Darters have a pale stripe running down the outside, Ruddy Darter legs are uniform black, and this can be seen on this specimen too.
So to the courting couple ;

I now had my doubts about these too, the male abdomen being a very deep red, and though the photos I took are not clear, there’s enough evidence for me to believe they are Ruddy as well, and this was confirmed when I read notes in the fieldguide about the significance of the way they were ovipositing, flicking the eggs into the water from just above the surface, a trait of Ruddy, whereas Common Darters would dip.

So there you go, if you can’t get a good enough view of a tandem couple, watch the way they lay their eggs, flickers or dippers, it makes all the difference.
So that was really unexpected, three Ruddy Darters before seeing a Common, the two flying way out over the water could have been either species, so Common Darter will have to wait until next time, and a more complete ID comparison.

Species Recorded : Ruddy Darter Sympetrum sanguineum

No comments:

Post a Comment