Monday, 30 May 2011

Four-spotted Chaser at Far Pasture Ponds

Sunday 29th May
With the forecast for Monday (my next proposed outing) diabolical, and the kids relatively quiet for once, I decided to flit along to nearby Far Pasture ponds on my trusty steed (bike), not much more than a five minute ride away. My reason for visiting here is twofold, one to see if I could connect with any more damsels, and secondly a Four-spotted Chaser (the first true dragonfly of the year) had been recorded here just last weekend.
On arrival the car park was empty bar a colourful male pheasant, and the hide was for once deserted, (it‘s usually populated by photographers anxious to get photos of a regular kingfisher). Again high winds and short sunny spells was the order of the day, nothing to be seen at first but I hoped that with a bit of patience something would appear during the sunnier periods.
And sure enough, first on the scene was a very flighty dragonfly which did a stop-start flypast in the blink of an eye. A few seconds later it re-appeared, again too fast to get my binoculars on it but from the jizz (general impression, size and shape) I was sure it was a four-spotted chaser. It was passing quite close to the hide and so fast did it dart around I just couldn’t get a fix on it to confirm. Again and again it zipped past, same result.
The winds got up again as the sun disappeared and the dragon vanished for a while.
I moved around to the right-side window of the hide where I found a little grebe nesting in the reeds further along then to my amazement the dragonfly was hovering just a few feet outside the window, then dipped down to perch on a pale stalk surrounded by greenery, easy to pick out but difficult to get a fix on as the high winds caused manic to-ing and fro-ing of the lush vegetation past my line of vision.
I opened the window and could see the dragonfly well with binoculars but couldn’t focus my camera, shot after shot coming out fuzzy or focussed on something else. It was certainly a Four-spotted Chaser, and it kept alighting from its perch but returning after a few seconds, a characteristic trait of this species and handy to know if you‘re after a photo, ‘til eventually at the 15th attempt I got a decent shot, (below)

Four-spotted Chaser  Libellula quadrimaculata

It’s called a Four-spotted Chaser because of the spots half-way along the wing (at the nodes) which are diagnostic of this species in Britain, the outer markings are called pterostigma which all dragonflies have though some are more noticeable than others, the males and females are very similar, tapering brown bodies with a black tip, yellow spots along the sides. The colouring becomes darker with age and looking at the field guide illustrations the females abdomen is slightly broader than that of the male and the claspers at the tip of the abdomen differ, females being of medium length and more or less parallel, the males are short and V-shaped, but I can’t be certain from this one photograph, and now armed with this knowledge will try to do better next time.
I also counted a single Large Red damsel and six blue damsels in the same area as the chaser, obviously this corner next to the hide was more sheltered, they would switch off their cloaking devices in unity and suddenly become visible as one when the sun shone, when a brief flight or tussle would end with them disappearing again as the atmosphere went back to gloom. I did manage to photograph a couple and view others through my bins, all identified as Azure, so still no Common Blues to report.
All in all not a bad little session, Four-spotted Chaser photographed, mission accomplished.

Sunday, 29 May 2011

The Quest begins - Part II

So to those difficult blue damsels. The two confusion species I mentioned (Common Blue and Azure) tend to occur in good numbers at the same sites so without getting a decent view of a perched individual it’s unlikely I can make a positive ID. As usual the bright blue and black individuals we have here are males on territory, though it has to be said they are not really aggressive towards each other, though more competitive when a female is on the scene.
There are subtle differences in markings of the males of the two species but THE big diagnostic pointer if you can get a clear view of it is the black shapes at the top of the abdomen just under the thorax (or body). In the Azure this is like a U shape, (just remember azUre) in the Common Blue it is like a mushroom. (coMmon). See illustration below. When I get a photo of the Common Blue I'll do a side by side comparison of the other spottable differences in the field.

Azure - U (left)  Common Blue - Mushroom (right)

Back to the quest and after the initial good fortune with the reds, the weather became rather unkind, sunny patches became few and far between, I was beginning to think I would never get an opportunity but as with the reds a couple of individuals suddenly appeared close by, photographed first to make sure they didn’t get away then viewed through binoculars to confirm both were Azure damselfly, (note U-shape at the top of the abdomen.)

Azure damselfly Coenagrion puella  (male)
There were only around 20 individuals present all told,, mostly on the raft of lilies centre pond, but could only ID the two I photographed with any certainty. Another time for the Common Blues then, not too downhearted though as they‘re not called ‘common’ for nothing.

It’s probably worth pointing out that there are in fact a number of similar blue and black species throughout the British Isles but so far only these two have been recorded in Gateshead (I won’t count the blue-tailed damsel, as it is mainly black and not easily mistaken for the other two) so for now these are all we need to be concerned with. Once I’ve recorded the Common Blue I’ll deal with the females.

Anyway, the sun disappeared altogether shortly after this and the damsels with it, but the pond is very clear here and I entertained myself with watching the fascinating underwater creatures, boatmen, diving beetles, caddis fly larvae, water scorpions, a myriad of creatures I’m not familiar with and quite a few damselfly nymphs as well, but the star sighting was indeed a couple of glimpses of Great Crested Newts as they came up for air before disappearing back into the weedy pond-bottom, vivid orange bellies interspersed with black on otherwise smoky grey bodies and very obvious undulating crests, great stuff!

The Quest begins - Part I

Friday 27th May, short spells of sunshine breaking up the periods of gloom, and chomping at the bit to start my quest an opportunity arises, as my better half has to go to Gibside to pick up an order of farm eggs. I join her for a coffee in the cafĂ© there, then we go our separate ways and the Dragon Hunt for 2011 finally gets under way. There are two main ponds at Gibside, both teeming with damsels on a good day, and today I choose the Lily Pond as I also want to try and spot a Great Crested Newt, nationally rare amphibians but occurring at a few sites around the borough and resident at Gibside.   
Targets are basically damsels, all five regularly recorded still-water species should be on the wing by now so camera at the ready, a ten minute walk brings me to the pond. I can see maybe a dozen bright blue and black damsels centre pond around a large raft of lilies, but these could be either of the two most common yet difficult species to separate in the field, the Common Blue and Azure damsels, so will have to wait for a closer look before calling one way or the other.
But my attention is caught by probably the easiest species to identify as a red damselfly settles on nearby vegetation. There are only two red species in the country, the Large Red which is common and widespread throughout, and the Small Red which only occurs in parts of southern England and Wales.
So a no-brainer then, Large Red Damsel is the first to be ticked and photographed, apt really, as despite my late start, they are invariably the first to be recorded each year anyway.


Large Red Damselfly (Pyrrhosoma nymphula) - male

The only question to be answered is do we have a male or a female? Well the males are by far the most numerous in the open as they hold and patrol territory on the lookout for the perched up females, as with most dragonfly species the females tend to spend long periods in cover of vegetation waiting for a passing male.
In this species the males are slimmer than the females and their brighter red abdomen only has black markings towards the tip, so my photograph does indeed shows a male. The females have larger but varying amounts of black along their duller red abdomen and are most often seen when in tandem (ie mating) with a male or egg-laying (ovipositing) on the pond. Luckily in the space of a few minutes today I managed to capture both of these events with my camera to confirm both male and female Large Red Damselfly :


Large Red Damselfly - female ovipositing

Large Red damsels - male and female in tandem
Apologies for poor quality photo, it was taken at distance but still shows the subtle differences in the sexes. The male (left) clasps the neck of the female (right) and mating can begin. Note the abdomen of the female is slighter fatter, duller, and has black rings at the segment joints.
The mating ritual takes about 20 minutes then the female will begin to deposit her eggs on vegetation around the pond surface.
Good to capture all those characteristics in one session, now for the blues . . . . . 

 


Saturday, 28 May 2011

Introduction

The scientific order of the Dragonflies (Odonata) is sub-divided into the dragonflies (Anisoptera) and damselflies (Zygoptera), the dragons being larger and bulkier than their colourful pin-like cousins the damsels. Their natural history is similar with two stages to their lives, an underwater larval stage (nymph) which can last a few months to a few years depending on the species, before they emerge during the summer months for their all too brief stay as the spectacular adults we see patrolling our waterways.

Locale

My local patch is the lower Derwent Valley in the west of the borough of Gateshead in northeast England. The borough usually has around 15 species recorded annually, and most of these appear at Kibblesworth Brickworks pools, which is unfortunately a few miles east of my ‘patch’, and some of the less common species take a bit of finding in my home valley. So my quest this year is twofold :

1. To observe and photograph every species recorded in the borough.
2. To locate and identify as many species as possible on my local patch ie the lower Derwent Valley

Main sites to cover here are the river Derwent itself and surrounding country parks, Thornley Woods pond, Far Pasture Ponds closest to me (so most regularly visited), and there's Gibside National Trust estate on the opposite side of the valley. At either end of the valley lies Shibdon Pond and Chopwell woods, both worth a visit or two, and dragonflies can occur well away from water so best to be alert at all times, I even have half a dozen species on my garden list.

Preparation

The first piece of equipment I pack for any dragonfly hunting trip is my trusty pair of 8 x 42 close-focussing binoculars. With these I can focus on anything down to about 4 ft making identification a lot easier than when I had standard binoculars which even at 10 x zoom were too far away from the subject to make subtle diagnostic traits visible.
I aim to get as good a photo as possible of every species I encounter, but a digital camera with a decent zoom is a useful piece of field equipment to have at any time, there are lots of confusion species in the world of dragons so the old adage of shoot first and ask questions later can help the observer to ID a lot you’re not sure about. This was especially true in one case for me back in 2006 when thinking I was photographing a Ruddy Darter at Kibblesworth brickworks pools I zoomed in on my digital screen to find I actually had photographed a Red-veined Darter, a rare migrant from Europe. Bonus!

Red-veined Darter (Kibblesworth 2006) 
note the red tinge on the wings - hence the name

As with bird watching, a good field guide is essential, and I use the Field Guide to the Dragonflies and Damselflies of Great Britain and Ireland by Steve Brooks and beautifully illustrated by Richard Lewington.
I never attempt to capture my quarry for fear of doing it harm so along with a notebook and pencil, that’s about all a dragon hunter needs, oh and a bottle of water and a sun hat, as like I say, dragonfly hunts invariably take place on warm sunny days.

The dragonfly season is already well under way with SIX species so far recorded in the borough of Gateshead , mostly damselflies which tend to emerge earlier than the majority of true dragons. The only downer at the moment is the weather, it’s been gloomy and strong winds for the last couple of weeks, far from ideal dragonfly weather so really just a matter of waiting for a sunny day (without babysitting duties) to explore one of the many waterways nearby. Bring it on !