Tag Archives: Enallagma cyathigerum

The disappearing dove

Posted on February 28, 2014 | 29 comments

Every year millions of migrating songbirds heading from Africa to Europe get blown out of the sky by weird people with shotguns. That combined with the policy in the UK of destroying habitat at an alarming rate is making life impossibly possibly difficult for some of our iconic bird species, one of which is the turtle dove (Streptopelia turtur, Dansk: turteldue).

But last summer I was exploring one of my regular haunts, Milton Country Park, on the northern edge of Cambridge, on a warm Saturday morning and the air was buzzing with insects including this handome hoverfly known as the ‘footballer‘ due to its rather fetching black and yellow striped thorax. This species is common in England reaching a peak in July which is when I snapped this individual.

The footballer hoverfly – Helophilus pendulus

And hoverflies aren’t the only abundant insects to be found in July. Milton Country Park is also home to mumerous species of Odonata, the dragonflies (Anisoptera) and damselflies (Zygoptera).

Common blue damselfly – Enallagma cyathigerum – perched on a seedhead

The Park has 4 big lakes:

…and a few other streams and pools, and despite the abundant human presence it remains a haven for some properly exotic wildlife including a bittern that appeared for a week or so last year, and the occasional osprey stopping off on migration from sub-Saharan Africa to breeding sites further north in the UK.

The great crested grebe (Podiceps cristatus, Dansk: toppet lappedykker) isn’t an exotic migrant but it’s a beautiful bird and can always be found here:

The grebe was almost hunted to extinction because its dense feathers were coveted as a substitute for fur. But it has recovered and can now be found on lakes over most of the UK. The one above is an adult and the one below still has the striped head markings of a juvenile.

But getting back to the point, the undoubted star of the show on this trip was the turtle dove:

The turtle dove is in very serious decline, I believe we have lost around 97% of our breeding population and it is anticipated it will become extinct in the UK by 2020 as it’s also under increasing pressure in Europe. The reason for its catastrophic decline is that it feeds on seeds from cereals and other plants and both of these are a scarce commodity in the fields of the UK at the time the doves need them.

So the birds arrive here in the UK exhausted after a heroic migration across the Sahara and the Mediterranean. And those that avoid the gun-toting imbeciles in southern Europe arrive here to find there’s not enough food. So as it takes them a long time to rest and feed and get back into breeding condition, they only have time for a maximum of one brood per season before they have to head all the way back. And this enforced curtailment of there breeding window means they just can’t sustain their numbers.

They arrive back in the UK from around mid April so I’ll try to capture some more photographs before they finally stop coming here all together.

29 Comments

Posted in Birds, Countryside walks, Damselflies, Hoverflies, Insects, Migrants, Milton Country Park, Ornithology, UK wildlife, Walks around Cambridge and Histon, water birds, Zygoptera

Tagged Anisoptera, common blue damselfly, Enallagma cyathigerum, footballer hoverfly, great crested grebe, Helophilus pendulus, milton country park, Odonata, Podiceps cristatus, Streptopelia turtur, turteldue, turtle dove, Zygoptera

Damsels of Fen Drayton

Posted on June 24, 2012 | 29 comments

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.

29 Comments

Posted in Anisoptera, Chaser dragonflies, Countryside walks, Damselflies, Dragonflies, Fen Drayton, Fen Drayton nature reserve, Hawker dragonflies, Insects, RSPB reserves, UK wildlife, Zygoptera

Tagged Aeshna mixta, Anisoptera, azure damselfly, blue tailed damselfly, Coenagrion puella, common blue damselfly, damselflies, damselfly mating, dragonflies, Enallagma cyathigerum, Erythromma najas, Fen Drayton, insects, Ischnura elegans, large red damselfly, Libellula fulva, Migrant hawker, Nature, Odanata, Odanates, Pyrrhosoma nymphula, red-eyed damselfly, RSPB, scarce chaser, true dragons, wheel position, wildlife, Zygoptera

A trip to the coast

Posted on July 31, 2011 | 2 comments

Last weekend I found myself poking into the nooks and crannies of Fareham in Hampshire. My only previous visits to Fareham had been when I was playing rugby against them some years ago. So it was fun to go back and explore it in a more leisurely fashion and find out what flora and fauna are there. And I was very pleasantly surprised. (A bit of a digression, but as I’m sitting writing this, back in Histon, I can hear a muntjac deer barking somewhere along our road).

Our friends who we were staying with live a short 10 minute walk from the town centre, a route which took me across a piece of ‘managed wasteland’ called the Gillies. This is a mixture of scrubby woodland and is thick with flowers and an abundance of insects and birds.

A common blue damselfly – Enallagma cyathigerum perched on a grass stem

I was hoping to see some species which I don’t see in Cambridgeshire, but alas this was not the case. But I guess that’s a tad churlish as I saw lots of great wildlife. The approach to the Gillies took me under a bridge which I think carries a railway line and glancing up as I passed under it early on the Saturday morning a pair of fallow deer sauntered across. I can’t think of any other town in the UK where I’ve seen that! Alas. I’d left my camera behind.

A somewhat tatterdemalion gatekeeper sipping nectar from yarrow flowers

A glance skyward in the midst of a butterfly hunt with the children, with several blackcaps singing in the bushes, revealed this buzzard circling lazily in the scorching sunshine over Fareham town centre:

…and then a few minutes later:

Shortly after the buzzard had disappeared we had ventured into some adjacent woodland where the quiet was shattered when a pair of fairly big birds chased each other into the top of a big old oak tree screeching as they went. They continued their slanging match for a couple of minutes and it turned out to be two sparrowhawks, and this one appeared in this gap for just long enough to snap a photograph. It’s not the best shot ever of a sparrowhawk but I really like it as it was in the midst of a fight and it sat still for just long enough for a single shot.

One creature I didn’t see but which my host told me she saw during a run through here earlier in the afternoon was a slow worm which slithered across the path infront of her. I haven’t seen one for many years but there are rare reptiles frequenting this place too. It’s a truly remarkable location.

So if you ever find yourself in Fareham feeling a tad disappointed by the 1950’s town planners’ attempts to rectify the damage done by the Luftwaffe, ask a local for directions to the Gillies and go and marvel at all the local wildlife.

2 Comments

Posted in Birds, Birds of prey, Butterflies, Damselflies, Mammals, Wildlife locations

Tagged Accipiter nisus, Anguis fragilis, blackcap, Buteo buteo, butterfly, Buzzard, common blue damselfly, deer, Enallagma cyathigerum, fallow deer, Fareham, gatekeeper, Gillies, Hampshire, Lepidoptera, mammals, Pyronia tithonus, reptile, slow worm, sparrowhawk, Sylvia atricapilla

Dragon hunt

Posted on May 23, 2011 | 3 comments

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.