Wrens in the garden

Wrens nest in our garden almost every year, and usually announce their presence with a loud burst of song that often takes me by surprise. This year they have a nest in an ivy-covered tree stump.

They tend to be quite secretive during the nesting season and spend a lot of time foraging close to the ground, but if I just sit quietly and wait they often become more confiding, allowing me to watch their foraging behaviour.

This year, for the first time, I've noticed their predilection for aphids. The underside of the leaves of our blackcurrant bushes are infested with greenfly and the wrens are constant visitors, picking off the insects with a beak that is akin to a pair of fine forceps. 

The individual food items may be tiny but they must have a high calorific value, because each aphid will be full of plant sap, which is predominantly sucrose.

I imagine that there may be other valuable prey amongst the aphids, including ladybird and hoverfly larvae. 

Being small and agile is an asset for a bird exploiting this food source, though I have also seen house sparrows visiting the blackcurrants for aphid snacks on several occasions.

A young wren from the first successful brood this year

A mirid bug nymph in my vegetable delivery

I've always hoped that I might find something interesting in fruit or vegetables bought from a greengrocers or supermarket - maybe a tropical spider or a scorpion. No luck yet, but this little mirid bug nymph Calocorus alpestris turned up in a cauliflower that we had delivered from a supermarket during Lockdown.

This is a sap-sucking plant bug - you can see its syringe-like mouthparts in the photo above. Its presence is rather reassuring, an indication that the cauliflower isn't loaded with pesticides. If it's safe for Calocoris to feed on, it's surely safe for a human to eat.

This is a nymph, with stubby, partially developed wings, and it will need to go through a final moult before it can become airborne.

On the British Bugs web site it's described as a local species, often found in damp woodlands, with a mainly upland and northern distribution in Britain, feeding on nettles.

I must thank @BritishBugs , @WildJennySteel and @Tracker_Bob on Twitter for identifying this for me.

Eric Simms' account of the dawn chorus in oak woodland.

The dawn chorus in an oak wood - surely the best reason to get out of bed before sunrise. Illustration by J.A Shepherd, from Songs of the Birds by Walter Garstang 1922.

Eric Simms. Woodland Birds. Collins 1971 p110

I remember one such chorus from a Midland oakwood. The morning was still and cold with white patches of mist clinging to the stream-sides that fringed the great expanse of oaks. In the far darkness a skylark began to rise in song and then at four o’clock a whitethroat sang a rapid little phrase and fell silent once more. A few minutes later a mob of carrion crows in the wood woke up in a frenzy of raucous caws and wild gobbled notes. This set off the rooks which with softer, conversational notes began to stir nearby. A cuckoo called in the distance and a plaintive ‘tic-tic’ from a robin brought a full song phrase from its neighbour. At eight minutes past four two redstarts started singing almost simultaneously and were followed by blackbird song, wood pigeon coos and the ‘ki-wik’ of a still-active tawny owl. As the dawn gradually rose the chorus reached its magnificent peak of song. The songs of song thrush, a garden warbler and a blackcap from a tree above could all be distinguished. By five o’clock wrens, chiffchaffs, chaffinches, tree pipits, nuthatches, marsh, blue and great tits could be heard, and their songs echoed through the wood. Gradually their chorus began to die away, leaving only a treecreeper and a stock dove in song, with the drumming of a great spotted woodpecker. With the dawn the colours of the bluebell glades brightened, and I saw a grizzled dog fox pick his way through the wet bracken and a mud-spattered boar badger trundled back to his sett on a slope in the wood. The sun was beginning to rise and as the birds began to feed and set about the affairs of the day the chorus died away.