Tag Archives: Cambridge

Insectivora

Posted on June 8, 2011 | Leave a comment

The hedgerows and the edges of country paths are home to an immense variety of small creatures, especially those which aren’t in the firing line for agricultural chemical spraying, and it can be easy to overlook them.

Last weekend I spent a morning chasing insects around and I followed a red admiral butterfly into a thicket of nettles where it sat tight with it’s wings closed. Over the next twenty minutes it very briefly opened its wings, but only partially, but enough to enable me to see that its colours were pristine:

And then it opened them fully, and the colours really were sumptuous:

…well worth half an hour stood in a nettle bed!

But I thought the half hour definitely wasn’t wasted when I looked down at my feet and saw this cluster of peacock caterpillars eating nettle leaves:

I moved to one side to get some pictures of the caterpillars, and fortunately after I’d spent some time doing that the red admiral was still in situ.

Peacocks are hardy butterflies which can be found over most of the UK including the Shetland Isles and can be found hibernating in garden sheds. They emerge from hibernation at any time of year if the weather is warm enough, they mate in March and lay eggs then the caterpillars can be seen from the middle of May into July.

Not only are they hardy, they are quit beautiful too. A close look at their wings reveals a fabulous array of brightly coloured detail:

Male peacocks hold fort in their territory and wait for passing females to pass by when they fly up to greet them and attempt to mate. Male and female peacocks are very difficult to tell apart and watching the males performing this courtship behaviour is one way to differentiate the genders.

And close to the same spot I was looking at the flowers and I spotted this hoverfly cleaning his eyes:

…and this beetle wandering over a convulvulus flower, I don’t know what it is but it has gorgeous colours:

The brambles in the hedgerows were also full of bees in the sunshine, many species of honey bees and bumble bees were harvesting nectar from the flowers:

White tailed bumble bee flying from flower to flower feeding on bramble nectar

And than this marvellous creature was hunting in my kitchen last week:

Violet ground beetle, isn’t he magnificent!

Violet ground beetles are carnivorous, as are their larvae. They hunt at night and hide up during the day under log piles or other cool dark places. They eat a variety of insects, including a number of species that gardeners would be glad to be rid of. They’re big beetles, around 3cm long, and they have irridescent blue or violet edges to the thorax and wing cases. So don’t use chemicals in your garden – let these guys get rid of your pests!

And now I’m looking forward to some warm sunny July days when the surrounding fields are full of butterflies. I’ll share some more insect photographs with you then.

A quick stroll round the meadow

Posted on May 30, 2011 | Leave a comment

Yesterday evening I accompanied the dog on a very quick circuit around Rowleys Meadow. I didn’t take my camera because I didn’t expect to be gone for very long, but fortunately I did pick up my binoculars.

Venturing along Guns Lane to the gap in the hedge which serves as the entrance to the Meadow I could hear a blackcap uttering its call in the undergrowth. As I was about to go through the gap it flew past me just in front and alighted in the bramble a few feet away and continued calling. It then circled around me for a minute or so as I entered the Meadow and sat singing in the trees and brambles while I stood in the hedge and watched. I didn’t linger for long as I guessed it was probably guarding a nearby nest. If only I’d had my camera with me!

Blackcap male – from a previous foray into the meadow

I’ve never spent so long so close to a blackcap, and it was lovely to see. There are a good number of them in the Meadow, and at least one nest, and they’re present in the hedgerows around the more open fields to the east of here too.

Moving on around the Meadow, chiffchaff were on parade in their customary locations and common whitethroat were singing on top of the brambles and in the low scrub.

Common whitethroat male proclaiming his territory

There are numerous common whitethroat in and around the Meadow which can be heard singing all through the day and many of the bramble thickets are home to their nests.

This female common whitethroat was waiting for me to move on before heading for the nest. I crouched down and hid in the long grass just long enough to get these photographs

When seen close up the female whitethroat is quite different to the male both in demeanour and plumage. She isn’t as bold in proclaiming her presence and her colours are more subdued, she doesn’t have the blue grey head of the male.

A kestrel was hovering over the Meadow at various heights for the duration of our walk, diving down into the undergrowth in pursuit of unwary rodents, but he didn’t seem to catch any. But next to the path there was evidence of another predator kill – the empty carcass from a sparrowhawk meal. The brown feathers remaining suggested it was a starling chick but it could also have been a blackbird or song thrush. There was insufficient forensic left to allow an unambiguous identification. Nature at its most brutal, but sparrowhawks have chicks to feed too. On the subject of our local birds of prey, a young buzzard was learning to fly over the Meadow today, it’s plumage was ragged and it was a less than competent aeronaut, and it’s great that they’re breeding in the area.

The other highlight of my quick stroll last night was the number of green woodpeckers. I counted seven, including two sightings of two together, one pair of which were squabbling on the ground. It’s quite possible, even likely, that I counted at least one of them twice, but I think there must have been at least 4-5 individuals.

A green woodpecker that I flushed out the grass

There’s lots of birdlife around at the moment and they all seem to be breeding successfully, including the local starling population.

And before I finish, I want to share this wild flower with you:

How gorgeous is that?!

It’s the flowerhead of hedge woundwort (Stachys sylvatica) which has just started blossoming in the hedgerows along Guns Lane in Histon. It contains an antiseptic oil which was utilised in days of yore in wound dressings, hence the name. Absolutely exquisite.

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.

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Posted in Anisoptera, Chaser dragonflies, Countryside walks, Damselflies, Dragonflies, Hawker dragonflies, Insects, Milton Country Park, Walks around Cambridge and Histon, Zygoptera

Tagged Anax imperator, Anisoptera, azure damselfly, blue tailed damselfly, Brachytron pratense, Cambridge, Coenagrion puella, Coenagrion pulchellum, common blue damselfly, damselflies, developmental biology, dragonflies, emperor dragonfly, Enallagma cyathigerum, four-spotted chaser, Grantchester Meadows, hairy dragonfly, Ischnura elegans, large red damselfly, Libellula fulva, Libellula quadrimaculata, milton country park, Pyrrhosoma nymphula, scarce chaser, variable damselfly, Zygoptera

The birds and the bees (and the flowers)

Posted on May 23, 2011 | Leave a comment

As our warmest and driest Spring on record turns into what is shaping up to be a warm and dry Summer, nature’s great events are occurring apace to exploit the prevailing climatic conditions.

The first swifts were seen over Histon 3 weeks ago (by me at least) after their heroic journey back to their breeding sites from overwintering in Africa. To celebrate this event I’ve spent several hours sitting in the garden of the Castle pub on Castle Hill in Cambridge enjoying a few convivial sharpeners and watching the swifts shrieking through the sky like an avian aerobatic team. I can heartily recommend both activities!

Wild flowers, including one of my favourites, white campion, are now in bloom:

White campion, Silene latifolia, decorating ditches and hedgerows

White campion is a dioecious plant which means the male and female reproductive machinery are on separate flowers. It grows in well drained earth and flowers from Spring to Autumn and is now delineating my walks across the open countryside. Another one of my favourite wild flowers is red clover (Trifolium pratense) which is a gorgeous colour and provides nourishment for bumble bees:

Red clover flower being harvested for pollen and nectar by a common carder bee (Bombus pascuorum). This is the national flower of Denmark.

And of course the local birdlife has been very busy breeding and raising chicks. Alot of species started this process earlier this year due to the unusually warm weather in Spring. I have a pair of blue tits raising a brood in the nestbox in my crab apple tree and my friend told me of a family of song thrushes which fledged from his garden a month ago. Which is very early.

A pair of great tit have been feeding their chicks on crushed peanuts which I put out on my bird feeder over the last month and last week they fledged and the whole family were feeding in my garden for just a day or two before they ventured further afield. (If you put nuts out for the birds during the breeding season please make sure you use crushed nuts as inexperienced parents can try to feed whole nuts to chicks and this can have fatal consequences). Great tits have over 70 different vocalisations which I think is remarkable, almost simple language! And on my explorations along the fields and hedgerows around Histon last weekend (21st May, 2011) I saw more great tit, blackcap and whitethroat all feeding gangs of fledglings:

Common whitethroat male, Sylvia communis

There are two species of whitethroat to be found locally, the common and the lesser (Sylvia curruca). They are distinguished by their song, which I won’t try to describe because I’ve never yet read a book which gives the remotest idea of what birdsong actually sounds like by a written description! But if you want to compare them try here for the common whitethroat, and here for the lesser whitethroat.

And another male whitethroat, this chap was singing long and loud, punctuated with characteristic jerky flights straight up in the air and back to the same spot

There are a good number of common whitethroat in the hedgerows north of Cambridge, lesser whitethroat are also here but are not so numerous. There are other distinguishing features between the two species, the lesser, as the name suggests is smaller (~11cm long compared to ~13 for the common), and is generally more grey with a pale grey head and noticeably darker grey ‘ear’ patches. It also has dark grey legs. Both species overwinter in sub-Saharan Africa, the common in central Africa and the lesser in eastern Africa.

Linnet can be regularly seen flying around the bramble thickets on the edges of the village and perching and singing on top of them. On Saturday early in the morning a fracas was going on in an elderbery tree in Rowleys Meadow in Histon which ended when a jay was chased out of the tree by a family of linnet and a family of whitethroat. The jay alighted on an adjacent shed to suss out the lie of the land and contemplate another raid whilst the indignant songbirds dispersed into some scrub to hide. Eventually the jay decided to keep his powder dry and disappeared into a nearby wood. Jays, like other members of the crow family, will raid nests of smaller birds for eggs and chicks, so it’s a perilous business being a small bird with a family to rear.

A linnet male perching on a bramble. When they’re not protecting a nest I’ve managed to sneak within 15 feet of linnet perched like this.

Linnet, Carduelis cannabina, are abundant resident and migrant breeders, although their numbers, as with many of our songbirds, are declining, and they are also passage and winter visitors. Due to their declining numbers over the past 40 years or so their conservation status is red, indicating they are globally threatened. They are finches which live in open country and farmland and feed on seeds.

Many species of moths, butterflies, bees, flowers and a plethora of other creatures are all appearing as trhe seasons are progressing and there’s something new to see every week!

Toad migration

Posted on April 2, 2011 | 1 comment

It’s the time of year when our resident amphibians are mating and heading for the nearest stretch of water to spawn. I find it a particularly stressful phenomenon due to the number of frogs and toads that need to cross roads and don’t make it. In my vicinity the completion of the guided busway running into the north of Cambridge has imposed an impassable barrier to thousands of common toads, Bufo bufo, which hibernate in the woods and hedgerows along the northern edge of the busway.

Pair of toads, the lady is the larger one underneath doing the legwork

It’s clear from the picture that the toads stand little or no chance of negotiating the sheer walls at the side of the busway – and even if they did they would have a further three to climb on the way to the lake and all four again on the way back. All this whilst numerous pedestrians and cyclists are making their way to school in Histon and work on Cambridge Science Park. It’s an extremely hazardous operation.

A pair that made it on their way to the water

When they make it to the water toads lay strings of eggs, as opposed to the gelatinous mass of eggs laid by frogs, and their tadpoles are slightly shorter and fatter than frogs. They feed on vegetable matter and absorb oxygen through their skin. As they grow they develop lungs and come to the surface to breathe. Eventually the tadpoles metamorphose into adult toads and the tail shrinks away at which point they leave the water as immature adults and will only return to the water to breed.

Adult toads differ from frogs in that they don’t hop, they walk. The colour of toads is also rather different, they have light ot dark brown warty skin with darker spots and frogs have more homogeneous green and smooth skin. And the eye colours of the toad is gorgeous – a lovely deep reddish gold. I like toads, they eat garden pests including slugs and are consequently good things to have around.

As with alot of creatures with the word ‘common‘ in their name, this is something of a misnomer, because of habitat destruction and the best attempts of predators including domestic cats they are no longer common. They secrete a toxic irritant through the skin but some predators are immune to this so they still get eaten.

It’s a real struggle being an amphibian in modern Britain so if you see one heading for the water – or on the return trip – please rescue it and help it on its way by placing it out of the way of humans, cars, cats etc.

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Posted in Amphibians, Common toad

Tagged breeding, Bufo bufo, Cambridge, Common toad, guided busway, migration, spawning

The Waxwing

Posted on December 3, 2010 | 2 comments

At this time of year a look at the ‘What’s About‘ blog page of the Cambridgeshire Bird Club (CBC) website to see if there are any interesting avian visitors in the locale is well worth while. On Monday this week (29th November 2010) there was a posting on the CBC site recording a sighting of waxwing in Brimley Road, Arbury, north Cambridge. They were spotted feeding on the berries of the many rowan trees in this street. Having never seen a waxwing and having marvelled at the spectacular pictures I’d seen of them I went there at lunchtime to have a look for myself. Alas, there were no waxwing to be seen but I persevered and went there again on Wednesday lunchtime with my friend and fellow wildlife enthusiast, Joe. Again to no avail. So we decided to make an early morning trip on Thursday, reasoning that the waxwing would be more likely to be there at breakfast time.

Thursday morning was snowy and absolutely freezing cold but I set off at 7.45 with my camera. On this occasion it was third time lucky:

Five of the seven waxwing frequenting Brimley
Road last Thursday

The trip was definitely worthwhile! It was a murky, grey, cold morning and until I got within around 30m of the birds I thought they were starlings. But as I got closer the crest became evident and then the colours… and they were absolutely stunning. A blaze of colour brightening up an otherwise grim morning.

The scientific name for waxwing is ‘Bombycilla garrulus‘ which means ‘chattering silk tail’. They are predominantly resident in conifer forests in Scandinavia and are partial winter migrants to the UK. I.e. some of the population head south in winter – known as an ‘irruption‘ – when food supplies in the north which consist of a variety of fruit and berries including crab apple, rowan, cotoneaster and mistletoe, are insufficient to support the whole population. An article in todays edition of the ‘Chronicle and Echo‘, the local newpaper in Northampton, reported that that current weather conditions in Scandinavia are really atrocious so record numbers of waxwing are migrating south giving rise to a ‘waxwing winter‘.

Waxwing feed in flocks, perching in the top of a tree and making occasional forays en masse to nearby fruit trees where they go into a ‘feeding frenzy’ for a few minutes before returning to their perch. This behaviour was observed on Brimley Road, the 7 birds there were sitting in the top of a crab apple tree and moving to an adjacent tree which looked like a rowan with white berries, to feed. There are species of rowan from China which have white berries so I guess this tree was a Chinese variety. We watched them for approximately 45 minutes during which time they appeared almost completely unfazed by our presence or the constant hubbub prevailing in a suburban street just before the school bell.

They are approximately the size of starling and at a distance can be mistaken for starling, as I did. They are 18cm long with a 34cm wingspan and they make a call like someone quietly ringing a small porcelain bell. There are up to approximately 200,000 pairs in Europe and it’s conservation status is green.

I don’t normally go twitching, especially in places as public as this, and I thought people would think we were a tad bonkers. But it was a pleasant surprise how many people stopped to ask us what we were looking at and showed a real interest in the birds. One chap even stopped his van in the middle of the road for a chat, only moving when the traffic behind honked the horn.

A great way to spend an hour before work, despite the freezing weather!