Sunday 21 December 2014

Observation of the Ruddy Darter.

I have visited the National Trust pond at Clamerkin for the last five seasons and have always enjoyed the sight on the resident population of Ruddy Darters.There seems to be a healthy colony with no shortage of territorial males,mating pairs, and ovipositing females.
Here on the Isle of Wight the first Ruddy Darter is on the wing towards the middle of June,perhaps one of the earliest in the country.Their season extends to the end of September and sometimes into October.
Below are two photographs of the first Ruddy of the year at Clamerkin taken on the 14th June 2010 ( five days earlier than the first sighting submitted on the British Dragonfly Society website).Particularly noticeable about this individual was its size,or rather the lack of it..Reference books state that this species varies in overall length from 33mm to 39mm. The estimated length of this one below has been calculated at around 30mm but seeing it myself on this reed leaf I would say that it could have well been no more than 25mm. Pretty small by Ruddy Darter standards I would have thought and I have certainly not encountered another  as small as this since.
The reason for this tiny fellow is unknown to me other than the fact that is was one of the first to emerge.There are always smaller and larger individuals in nature so maybe it is not so uncommon.

Another unusual sight to see was this photograph below of a mature female.The abdomen of the female is yellow-ochre whereas of course,the abdomen in a mature male is blood red.
It will be noticed here that this female has developed  a very red abdomen similar to the male. Apparently very mature females of several darter species can show some red on their abdomens but this one is quite extensive.Indications to confirm this female as a Ruddy are the seemingly all black legs and the dark bar immediately behind the head.
The photograph was taken on the 12th September which is towards the end of this darters season as mentioned earlier.