Category Archives: Hawker dragonflies

Dragonfly drama

Early last Saturday morning I set off for Paxton Pits, a group of lakes on the edge of St Neots, between Bedford and Cambridge. It was anticapted that we wouldn’t see much birdlife but there could be some inteersting dragonfly activity. And apart from a lone turtle dove (which justifies the trip on its own!) and a sparrowhawk, we noticed surprisingly few birds. But the Odanata were there in abundance with large numbers of various species of damsels and true dragons.


Common blue damselfly

I spotted this common blue (Enallagma cyathigerum) before I’d even got out the car. This one a male, was perched on a seed head at the edge of the carpark and there were several others in the vicinity warming themselves up in the early morning sunshine. At the other side of the carpark is the visitor centre which has a small pond outside and over the pond were a red eyed damsel (Erythromma najas) and another common blue warming up on the same rush leaf:

Paxton Pits are disused gravel workings and have been turned into a nature reserve that is managed by Huntingdonshire District Council with the back up of the voluteers of the ‘Friends of Paxton Pits’. If you happen to be contemplating a visit to the Pits, there is a lot of information on their website: (https://sites.google.com/site/paxtonpitsnaturereserve/home), and the reserve also has a blog where sightings at the lakes can be recorded: (http://paxtonpits.blogspot.co.uk/). The website lists all the Odanata that have been resident there and many of them were on display on Saturday. They don’t all emerge at the same time of year so it would never be possible to see all of them during one visit.


Another common blue damsel on final approach to land on a stinging nettle stem

The Pits are adjacent to the River Great Ouse and swarms (literally!) of banded demoiselles (Calopteryx splendens) were fluttering within 20m or so of the banks of the river. The banded demoiselle is one of two species of demoiselle in the UK and the only one in the east of England, and I think they’re absolutely beautiful as they sparkle in direct sunlight:

A female banded demoiselle perched on top of a nettle (I like the background here – out of focus brambles)

The other species of UK demoiselle is called the ‘beautiful demoiselle’ (Calopteryx virgo) and is found in the south and west but not the east. It is most easily distinguished from the banded version because the wing pigmentation in the male extends to the base of the wing, so it’s a much bigger spot than those on the wings of these banded demoiselles:

Above and below: male banded demoiselles

And the female beautiful demoiselle  has broader wings with a brown tint that’s lacking in the banded demoiselle. The male demoiselles were busy chasing females with all thoughts turned to mating.

But in the midst of all the the mating activity, danger, as always, was lurking in the undergrowth. This unfortunate female common blue damsel had been caught in  a spider web and was in the midst of a mortal struggle with the owner, which she eventually lost:

The male common blue was also caught in the web and was struggling to extricate himself. Fortunately for him, all the spiders efforts were needed to subdue the female and whilst it was otherwise distracted he made his escape whilst the female eventually succumbed to the spider venom.

A dragonfly larva having scaled a stem to leave the water will shortly burst out of its skin and fly off as an adult dragon

It’s also that time of year when dragonfly larvae are metamorphosing into adults. The larval stage of all dragonflies is aquatic and so they require gills or ‘caudal lamellae‘ to breath underwater, and these can be seen protruding from the end of the abdomen of the larva above. At the end of its aquatic life the larva climbs a stem out of the water and emerges from its larval skin as an adult, leaving behind its discarded outer casing, or ‘exuvia‘:

Dragonfly exuvia  – a dried out larval husk left behind on a rush stem after the new adult has flown

As well as the damsels, several species of true dragons were on the wing including brown hawker, migrant hawker, black tailed skimmer, and the grandaddy of all UK dragons, the emperor (Anax imperator):

Emperor dragonfly male patrolling his stretch of water against allcomers

The emperor, as its name suggests, is a whopper. It is also an aggressive defender of its territory, a consummate aeronaut and a ferocious hunter, taking prey as big as other dragonflies. It’s easily distinguished from other dragons by its sheer bulk, the apple green thorax and the drooping abdomen. I sat and watched this one for some time and he rewarded my patience by posing for a portrait on a stem just  a few metres away:

And after all the dragon activity I peered into the water on the way home and spotted this little chap:

A young newt

I don’t know what species of newt this is but it’s still so young it hasn’t adapted to air breathing and still has its feathery gills which are visible just in front of the fore legs.

It’s been a long time since I last posted so it’s good to be back Life should be generally less busy for the back end of the year and I’ve got lots to share, so hopefully I can start to post more regularly again!

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Damsels of Fen Drayton

One of the reasons for my trip to Fen Drayton a few weeks ago was to have a look to see which of our dragonflies were out and about. I went in early June and that time of year is a little early for the true dragons to have emerged, although it’s not impossible. But despite the shortage of the true dragons, the hedgerows and lake sides were abuzz with damselflies.


Male red-eyed damselfly – Erythromma najas

Dragonflies and damselfies are the two members of the taxonomic order ‘Odanata‘ or Odanates. There are two sub-orders within the Odanata: the Anisoptera – the true dragonflies, and Zygoptera – damselflies.

Azure damselfly – Coenagrion puella – the blue form of the immature female

Damselflies in the UK are approximately 4-5cm (1.5-2 inches) long and have thin abdomens and are all smaller and more delicate than the chunkier dragonflies. Having said that, the biggest living Odanate is currently a damselfly who resides in the rainforests of Central America, it has a wingspan of 19cm (7.5 inches) and the abdomen is 10cm (4 inches) long. A real whopper!

Blue tailed damselfly – Ischnura elegans – immature femaleBlue tailed damselfly – immature male – Ischnura elegans

Male and female Odanates, and immature and mature individuals, can often be distinguished by colour. The common blue female below is conspicuously brown so the species gets its name from the electric blue colour of the male. The common blue can easily be confused with the variable damselfly which is the same blue colour, but they are distinguished by the black markings on segment 2 of the abdomen which is shaped like a goblet on the variable and a club on the common blue. Also, the antehumoral stripes (on the side of the thorax) are complete on the common blue and broken on the variable. Although, as the name suggests, the variable is indeed variable and it can make distinguishing the two species a little tricky.


Common blue damselfly female – Enallagma cyathigerum – the only common blue we saw on this trip, perched on my friends finger

The black goblet on segment 2 is visible under the front of the wings on the variable damselfly below. But confusingly, it’s living up to its name because the antehumoral stripes are unbroken.

Male damselflies have two sets of paired claspers at the end of the abdomen which it uses to clasp the female on her pronotum, which is the protrusion in the middle of the back of the head. The claspers have tiny hooks on them which match grooves in the female pronotum and in order to avoid procreational mismatches the hooks and grooves are species specific.

Variable damselfly – Coenagrion pulchellum

In the picture above a variable male has clasped his lady by the pronotum. Male damselflies have primary genitalia at the end of the abdomen on the 8th segment, but in order for fertilisation to take place he needs to transfer a ‘spermatophore’ from the primary genitalia to the secondary genitalia on the second segment at the thoracic end of the abdomen. The female then curls round in to the ‘wheel’ position to transfer the sperm to her genitalia which are underneath her 8th abdominal segment.

A pair of variable damsels in the wheel position

All the Odanates are carnivores, and the larvae which hatch from eggs layed under water are ferocious carnivores, the larger ones will even take small fish! On one occasion last year while I was photographing large red damselflies (Pyrrhosoma  nymphula), a large hawker dragonfly (I think it was a migrant hawker, Aeshna mixta) which had been buzzing around higher up for several minutes suddenly dived down and caught one of my large red damsels. In a few seconds the migrant butchered it and ate it on the wing and the inedible bits of wing and leg were discarded and rained down around me.

Scarce chaser – an immature male

A lone Anisopteran, or ‘true’ dragon was spotted on this trip and it was an immature scarce chaser, Libellula fulva. He was a lovely mustard colour and he can be differentiated from the female by the colour of the thorax which is dark grey in the female, and from the male adult who is electric blue. He undergoes quite a transformation in transitioning from immature to adult.

2011 – That was the year that was

Every month of the year has different conditions which create environmental niches that favour different flora, fauna and stages of life cycles. So as 2011 rushes headlong to its wintry conclusion, for my last post of the year I was going to select a single photograph to represent the month to month changes in our wildlife throughout the year. And that was of course impossible for a number of reasons, mainly because it was impossible to represent any one month with a single image, and also because I have lots of images that I like and I want to share. I eventually managed to whittle the number down to an average of two per month which include a wide range of our native creatures in the UK including birds (migrants and natives), butterflies, moths, flowers, amphibians and fungi. I hope you like them!

January

Every autumn  lots of bird species vacate our shores to head to warmer parts of the world while we endure the cold of winter, and they’re replaced by other species which come from the north to the relative warmth of the UK in winter. Last year the autumn and winter weather in Scandinavia was ferocious and consequently many birds arrived here in larger numbers than usual, including the gorgeous waxwing. Along with the waxwing, redwing and fieldfare came too, as they do every year, and remained until the spring, providing some welcome colour.

On a bright cold January day a lone fieldfare perched in a tree

February

February was cold and the middle of the month saw us taking the children to the coast for our annual spring half term excursion, and this year we headed to the Suffolk coast at Dunwich. Dunwich is a really interesting place for lots of reasons, not least because the wildlife there is rich and varied. One of the harbingers of springtime which I look forward to every year is the flowering of snowdrops, and the woods on the edge of Dunwich were covered in them:


A carpet of snowdrops in the woods at Dunwich Greyfriars

March

By March many flowers were blooming and the fauna was turning it’s thoughts to matters procreational. And this dunnock was no exception:


A dunnock serenading the ladies from a bramble stem on Cambridge Science Park

Dunnocks have a rather to-the-point approach to the art of regeneration. They don’t get together in pairs as most birds do, they form small groups and mate with multiple partners and the males go as far as to remove packets of sperm from the cloaca of females who have been inseminated by rivals prior to passing on their own DNA. No nonsense!


A robin singing for a mate in an alder tree, also on Cambridge Science Park

And of course the birds aren’t the only creatures to get the urge in March. For the past 2-3 years a guided busway has been built between St Ives and Cambridge and as it approaches Cambridge Science Park it passes alongside a lake that is a spawning ground for thousands of toads which live in the adjacent woods and fields. The busway has therefore cut off the toads from the lake and, driven by the unstoppable instinct to reproduce, this pair were trying unsuccessfully to negotiate the sheer walls of the track. For a week in March I would get off my bike every morning on the way to work to help as many of them across as I could find.


The male toad is hitching a lift on the back of the much larger female on the way to the water to spawn

The male toad locks onto the back of the female with his front claws around her chest and he’s not at all keen to relinquish his grip until they’ve reached the water and he’s fertilised her eggs. After which armies of lone toads can be seen heading back the other way.

Fortunately for the toads Cambridge City Council funded the installation of toad tunnels under the busway so next year they should be able to negotitate the track and avoid the carnage which would otherwise have ensued. Hats off to the Council!

April

This month was a real wildlife fest and many types of creature allowed me to take some great photographs. The trees now have shooting leaves so everywhere has that lovely green colour from all the fresh growth.


Windswept male yellowhammer in the top of a hawthorn tree

The yellowhammer is a species which has become less and less common in recent decades as a result of hedgerow destruction and other modern farming methods, but we’re lucky to have plenty of hedgerows still in situ on the outskirts of Histon, and consequently, good numbers of these lovely yellow buntings. The hedgerow this one is on is mature and has old oak and ash trees in so it plays host to alot of bird species including blackcap, chiffchaff, dunnock, common whitethroat and green woodpecker, to name but a few.

Whilst sitting watching TV late one evening in March, what I initially thought was a bat emerged from behind the sofa I was sitting on with my wife. There had been no prior warning of its presence and myself and my wife both levitated off the sofa uttering something along the lines of “What the heck was that!?”. It fluttered into a lampshade where it staid long enough to get a photograph, and it turned out to be an emperor moth:


Our emperor moth inside a lamp. I though creatures like that only lived in tropical rainforests!

Unfortunately, a couple of days later I found her dead (she was the female of the species) still inside the lampshade. I extricated her and measured her and she was 7cm wingtip to wingtip. A magnificent beast.


A willow warbler beautifully framed by new leaves and blossom of the blackthorn tree

These little warblers which weigh on average around 9g have just arrived from southern Africa. I think bird migration is one of the most amazing natural phemonena – how does such a tiny creature navigate and survive a flight across the Sahara and then the Mediterranean? It’s absolutely incredible.


A pair of great crested newts getting ready to mate in a shallow pond – male on the left, more slender female to the right

The great crested newt was probably the highlight of my year. I’d never seen a newt before and in this pond there were great crested, palmate and smooth newts. I turned the flash power down and used an 18-55mm lens and got some reasonably good photographs of the newts underwater. And that at 1am after a few hours in the pub!

May

I’ve spent many a fruitless hour chasing orange spot butterflies up and down the hedgerows of Cambridgeshire, but they never seemed to settle for long enough to get a photograph. But one morning in May I must have timed it just right, they were in the mating mood.


Female orange spot announcing her availability in somewhat unambiguous fashion to a passing male who was just out of shot


Common whitethroat – these warblers also migrate to the UK from sub-Saharan Africa

The common whitethroat breeds in my local fields in good numbers. It’s easy to identify by its song and the way it perches on brambles and low scrub and then flits almost vertically up into the air to alight a few seconds later close to where it took off from and continue singing. This one is a male, he has a blue/grey head whereas the female has a brown head. As well as avian migrants from warmer climes, at this time of year many species of dragonfly are emerging:


Scarce chaser dragonfly at Milton Country Park

I like dragonflies. In the days of the dinosaurs there were dragonflies with a 75cm wingspan! They are fun to photograph (and often, not too difficult) they look awesome, and they have very interesting life cycles. My scarce chaser sat on a seed head for several minutes whilst I stood a few feet away photographing other dragons and damsels, occassionally he took off to circle the pond before returning to the same spot where he let me get to within around 50cm to capture his portrait.

June

In a normal year the weather will be warming up  nicely by June and flowers and insects and birds should be in abundance. But 2011 wasn’t a normal year, April was unseasonally warm which kick started everything, but the rest of spring and summer were cold and this had dire consequences for many butterflies and other species. One of the few that I did see in reasonable  numbers this year, although not as many as last year, was the large skipper.


Large skipper feasting on the nectar of a thistle

The marsh woundwort is so called because it has been applied to wounds to assist the healing process. I don’t know what the medical basis for that is, maybe it has antispetic properties. It  has a beautiful flowerhead and is one a good number of wild flowers growing in the drainage dikes on the local farmland around Cambridge.

Marsh woundwort poking it’s lovely head out of a drainage ditch which is full of various wild flowers every year

July

I found this splendid looking cricket lurking in the grass in a field on the edge of Histon. I first thought it was a very green grasshopper until I looked more closely at the photograph, and it turned out to be a Roesels bush cricket. It is an introduced species from mainland Europe which until recently was only found in the most southerly parts of England. There are two varieties and this is the long winged one which can colonise further afield faster than its short winged cousin, and is now as far north as Cambridgeshire and beyond.


Long winged Roesels bush cricket

This was the first of its kind that I’d seen and a few days later another one appeared on a blind in my house, so I guess thay can’t be that uncommon in this region now.

A pair of juvenile linnets

Before I got out walking in my local countryside around Histon I can’t remember the last time I saw a linnet, but they breed here in good numbers and in the winter flocks of many tens to hundreds can be seen on farmland around and about Histon. Linnet are finches which feed on seeds and the adult males are splendid with a cerise breast and a crimson spot on their foreheads.

August

When I was at school, many years ago, my Dad would feed the birds in the garden and it wasn’t particularly unusual to see the occasional bullfinch.  But mainly as a result of persecution their numbers declined dramatically through the 1970’s and 80’s and I didn’t see one for years. The males are beautiful birds and I’ve been after a good photograph of one for a long time. And finally…


A male bullfinch crunching seeds at RSPB Fen Drayton

I love this picture – so far it’s the first and only half decent one I’ve managed. Hopefully I’ll get a few more to share with you in 2012.

Later in August, we were on holiday in Northumberland, and amongst the many gulls and other seabirds on the beach at Seahouses was this redshank. I think it’s nature at it’s aesthetic best!


A lone redshank looking for nourishment in the rockpools at Seahouses

September

The biggest garden spider I’ve ever seen – she was around 4cm across

Another of natures harbingers, this time of autumn. My garden fills up with these polyocular purveyors of terror in September, and this lady was huge. She was 4cm across and was big enough to distract my son from a telling off. ‘Dad, there’s a big spider in my window‘ was an imaginative and very effective way to divert my attention from the misdemeanour of the moment. I ran to get my camera and I had to lay horizontally out of the bedroom window to take this photograph, as a result of which I couldn’t stay still for more than a few seconds!

October

After the coldest summer for 18 years we then had a mild autumn which meant that many creatures could be found out and about long after they have normally  migrated or hibernated, or died off. Swallows and swifts were still being seen into October and a bumblebee flew past my lab window one day last week. During a visit to Milton Country Park, on the northern edge of Cambridge, on 28th October, to see what winter wildfowl had arrived, there were some winter visitors including tufted duck, gadwall and widgeon. But the pontoon I was stood on had around half a dozen common darter dragonflies on it along with several species of damselfly in the surrounding reedbed and a lone migrant hawker patrolling the air which took a common darter and butchered it on the wing right over my head. Dragonflies can be seen late in the year when the weather permits, but even so I was surprised to see so many at the end of October.

A pair of common darters mating in the late autumn sunshine

November

One of my November excursions took me to RSPB Fowlmere, between Cambridge and Royston, which is renowned for its water rails. I don’t think I’d ever seen one before but I was tipped off by a fellow naturalist that there was one in front of a particular hide, so I headed off there and there it was, busy foraging in the pond for the whole hour I sat there. It was very murky so the photographic conditions were difficult, but I managed to get a couple of decent pictures and I particularly like this one:

A water rail in the primeval swamps of Cambridgeshire!

And another of my trips in November was to Norsey Wood in Essex which is a very different ecosystem to Fowlmere, consisting of ancient oak, beech and birch wood. So in autumn the forest floor is a really good location for fungi and this fly agaric was one of a large group growing out of the leaf litter.


Fly agaric mushroom amongst the fallen beech leaves of Norsey Wood

December

And finally, a wildlife success story is the long tailed tit. Until the last 10-15 years I only saw these occasionally but they now seem to be common, in direct contrast to so many other species of bird whose numbers are declining. I regularly see flocks of long tailed tits on the feeders in my garden and in the hedgerows and woods around Histon. They’re gorgeous little birds and I love watching a flock of them follow each other one after the other along a hedgerow before bunching together when they have found a food  source and then heading off again in line astern.

A long tailed tit in the hedges along Guns Lane in Histon

I stood quietly for several minutes watching the flock of around 15 birds that this one belonged to and they didn’t seem at all bothered by me as they picked insects from the trees.

So there you have it. 2011 in pictures. If you had the stamina to get this far, thankyou and I hope you enjoyed it.

Best wishes for a very happy Christmas and a peaceful and successful New Year from The Naturephile!

Hawkers and darters

A lunchtime visit to Milton Country Park on the northern periphery of Cambridge this week to look for dragonflies turned out to be an hour well spent. For the first 10 minutes they were conspicuous by their absence but then a brown hawker appeared over a small pond, very distinctive with it’s rufous wings shimmering in the sunlight. I tried to photograph it in flight but it proved beyond my talents. Even though there were three or four whizzing around the pond at any one time  I moved to a place under a tree which was overhanging the water and knelt down and waited. Within a couple of minutes a female brown hawker alighted on a log floating in the water and started ovipositing:

She seemed to be completely unfazed by my presence and busily worked her way along the log probing below and above the waterline for a suitable crevice to secrete her eggs.

She was there for around 10-15 minutes in total and every so often she took off but seemed to always to return either to her log or to a spot on the pond bank 5-6 feet from me. Even when my friend, Joe, came to see she still went about her business taking little notice of us.



She eventually departed along with all the other hawkers so we strolled along to a different location which was a wooden jetty protruding into another of the lakes. It’s surrounded all the way by dense rushes and has previously been a good place to see dragons. And that didn’t let us down either. We saw only two species, a pair of blue tailed damselfy and numerous common darters. All males. The males of this species are easily distinguished from the female as they are a glorious red and gold compared to the less vibrant green of the female.

The male of the species…

…and the lady:

There were several male common darters perched along the wooden jetty (the female above was snapped in Histon a couple of weeks ago), they were also happy to let us get up close and would occasionally dart away suddenly to chase a prey insect before returning to the same spot.


The compound eyes of the common darter – I like the depth of field in this picture rendering just the dragon in focus

When I was out for a stroll with my friend, David, who’s a bit of a dragonfly expert, last weekend, we found a dead migrant hawker dragonfly. We were marvelling at the complexity of the compound eye and he told me that a chap in the States had counted the facets in the eye of an American species, and apparently he got up to around 28000! He must have had a string of long winter evenings to fill. But dragonflies are amazing creatures and I can see how they inspired him to want to do it.

I also took a couple of nice bird photo’s on this trip but I’ll save those until next time.

Dragon hunt

Not the fire-breathing type but Anisoptera. I spotted the first dragon this year over Easter during a picnic at Grantchester Meadows, south of Cambridge. It wasn’t, technically speaking a dragonfly, but a damselfly, specifically, a large red damselfly (Pyrrhosoma nymphula), which is one of the first to emerge after the Winter. Due to the weather this year many things have happened earlier than usual and the large red was out and about in late April. And they are magnificently red:


Large red damselfly male. There are three colour forms of the female all of which have more dark banding on the abdomen than the male

Milton Country Park on the northern edge of Cambridge is a great place to see numerous species of dragonfly and damselfly, and on a foray there on Saturday with my friend, David, we counted 10 species. Dragonflies – I’m using this generic term interchangeably to cover dragonflies (Anisoptera) and damselflies (Zygoptera) – are remarkable creatures, there are few more accomplished aeronauts in the animal kingdom, and the various life cycles are amazing.

The life cycles involve an aqautic larval stage, the larvae hatching from eggs laid either underwater or inside plant material close to the waters surface. The duration of the larval stage is affected by various factors including temperature, and for species such as the blue tailed damselfly (Ischnura elegans), this results in the difference in duration of the larval stadium (developmental stage) of 1 year in warmer parts and 2 years where it’s colder.


Blue tailed damselfly, immature male

After the larval stage, metamorphosis, switched on by warmer temperatures and extended day length, occurs over a few weeks and concludes with the emergence of the adult from the larval cuticle when it will dry out and take to the air. The drying out process is hazardous as it renders the new adults susceptible to predation by birds, consequently they time their emergence to occur at night or in the early morning. New adult dragonflies then disperse from water for approximately a few days to a few weeks, until they are sexually mature, when they return to the water for the serious business of finding a mate and starting the whole process over again.

This is a very incomplete and generic description of the dragonfly lifecycle, but if you want to discover more I recommend a book called ‘Field guide to the dragonflies and damselflies of Great Britain and Ireland’ written by Steve Brooks and illustrated by Richard Lewington (ISBN 978 0 9531399 0 3). It’s a very well written book with lots of easy to read information and high quality illustrations. And because there are only around 40 or so species of dragon and damselfy in GB and Ireland it won’t take you all year to read!

On our walk we saw hairy and emperor dragonflies (Brachytron pratense and Anax imperator respectively), both species of hawker, which I couldn’t get good photographs of as they were whizzing around over the water at high speed and never seemed to settle within range. Similarly with the four-spotted chaser (Libellula quadrimaculata), but then as we positioned ourselves in a very good viewing location on one of the smaller lakes a scarce chaser (Libellula fulva) appeared on a nearby seedhead and with occasional forays stayed there all the time we were there, giving some great photo opportunities:


Scarce chaser male, the female has a yellow abdomen with a thin black spine and doesn’t have the three black end segments

There were lots of damselflies too, apart from the large red and blue tailed already mentioned. Variable damselfly (Coenagrion pulchellum):

Azure damselfly (Coenagrion puella):

And common blue damselfly (Enallagma cyathigerum)

This pair of common blues are in ‘tandem’ with the green eyed female underneath. This position is adopted by non-territorial damselflies where the male grips the female behind the head and in this way ensures that no other male can mate with her before his eggs have been laid – a process called ‘ovipositing’. The eggs hatch out after 2-5 weeks and the larvae begin their development underwater where they are ambush predators, feeding on a variety of prey from other insect larvae to tadpoles and even small fish!

They are amazing creatures, and more species will be emerging over the next weeks and month so hopefully I can gather some more images of other species for subsequent posts before the Summer ends.

Dragonfly discoveries

Dragonflies are amazing insects which it seems can be seen just about anywhere. In 2010 I’ve even spotted them over my garden in Histon. It occurred to me I should put some effort into photographing and learning about them as I sat with my family eating a picnic on a bench overlooking the fountain in the Cambridge University Botanical Gardens. Numerous small, magnificently bright red, individuals were whizzing around the pond, and a few big blue ones a short distance away from the pond (the small red ones were a species of darter, and the big blue ones were hawkers – probably migrant hawkers). I attempted to photograph these for subsequent identification but alas my photographic skills were’t up to the job on that occasion. Despite that I looked up some information and lots of great pictures at http://www.dragonflysoc.org.uk/home.html. This is a great website and started me off on a journey of discovery which is now pretty much finished this year but which I plan to resume as soon as possible next year.

Subsequent walks around Milton Country Park and the fields north of Histon provided lots of opportunities to see many species of dragonflies and damselflies:


Female brown hawker sunbathing on a birdbox at Milton Country Park

Migrant hawker male. The yellow ‘golf tee’ on segment S2 is diagnostic 

Dragonflies originate from species which fossil records date to the Carboniferous period, around 300 million years ago, and could have a wingspan up to 70cm! They comprise the taxonomic sub-order known as ‘Anisoptera‘ and are part of the order ‘Odonata‘ which also includes damselflies (Zygoptera) and another group which is virtually extinct called ‘Anisozygoptera‘. There are now around 5300 species of dragonflies of which approximately 40 reside in the UK.

Dragonflies lay eggs underwater either loose, protected by a hygroscopic gel, or inside plants. The eggs of some species can lie dormant over winter and resume development when temperatures rise in springtime. Time to hatching is temperature dependent but is usually around 2-5 weeks and the larvae develop in water, all British species overwinter once as larvae but time to adulthood can be up to 5 years. Metamorphosis from larva to adult is triggered by increasing day length and temperature in spring, and includes the transition to breathing air and growth of their incredible compound eyes. Each eye is made up of around 29000 individual elements called ‘ommatidia‘. They also possess three addtional ‘simple eyes’ call ‘ocelli‘ which are sensitive to light intensity and assist in controlling flight via direct nerve connections to the flight muscles. Dragonflies have excellent colour vision and can also see ultra violet light. It makes me wonder what the neural activity behind all that optical prowess is capable of: are dragonflies merely responding directly to visual stimuli via reflex arcs, or is there more sophisticated image processing going on?


Common darter, immature male

Common darter, female. Note the compound eye.

Dragonfly larvae are ambush predators feeding on moving prey including other insect larvae, snails, small fish and tadpoles. Adults catch other insects in flight, holding their legs out in front like a bread basket to scoop prey from the air such as flies, flying ants, mosquitoes and even other, smaller, dragon flies.

Newly emergent dragonflies are powerful fliers and disperse widely. They are often seen a long way from water and can even cross seas. They reach maturity after a few days to a few weeks, a process also controlled by temperature, when the males will congregate at vantage points near water where females come to oviposit. The male will grasp the female around the head with his anal appendages and attempt to mate with the female by swinging her round to form the ‘copulatory wheel’ enabling him to pass a packet of sperm from the secondary male sexual organs located on his second abdominal segment to the female sex organs located on her eighth abdominal segment. After mating, sometimes under the guard of the male, to ensure his sperm is not displaced by another male, the female will oviposit underwater. And so the cycle begins again.


Broad bodied chaser – female