Weekly Nature Watch

Country View 20.4.16

on .

One single swallow does not of course, mean that summer’s here! The first one, seen not by me but by my farming neighbour, was described as sitting on a wire, shoulders hunched, braving the icy Arctic wind. I conjectured that it might even have been contemplating a rapid return to Africa! The second swallow, although perhaps also not necessarily signifying that summer has after all shown its face, was seen on the first day upon which the sun shone and the mercury veritably soared. Yet even two do not a summer make!

It probably will be days, perhaps weeks, before I am likely to witness the febrile chatterings of courting male swallows. Amongst the strange assembly of notes that issue from the short but inordinately wide bill of a ‘singing’ swallow, are some distinctly mellow and musical ones, yet as a whole, the swallow’s courtship song meanders, at times feverishly but seldom predictably. It is a strange, seemingly random series of notes. However it clearly works and certainly captivates the females of the species!

With sun splitting the sky, there has been an obviously audible response by the birds. Very noticeably there has been a considerable resurgence in the song thrush population and my resident mavis is fairly banging the music out. However, I suspect there is locally at least, a shortage of females, otherwise by now, his music might have been modified. Once thrushes are paired, the singing becomes slightly less clamorous. Thus far there has been no letting up at all!

There’s been plenty of colour too with a host of multi coloured but very red faced goldfinches and greenish yellow siskins swarming over the sunflower hearts and the nyjer seed. There is greening too in the trees and indeed on the ground although my farming friends are still waiting for the grass to grow sufficiently for their beasts to get the chance to stretch their legs and after a cramped winter indoors, at last get the chance to chomp away at the grass. In this airt at least, cattle do get to go out of doors. Not, as far as I’m aware, for local farmers, the concept of yarded cattle, never to tread the grass!

There has I believe, been another significant resurgence. Almost everywhere I go, there are jenny wrens (incongruously named ‘jenny’ despite the songsters being very much all-male) rattling out their amazingly loud volleys of song. The volume achieved by this minuscule bird has surely to be ounce for ounce and decibel for decibel, the most loudly audible of all bird pronouncements. When two rival cock birds get into a vocal competition in which one responds to the vocalisation of the other, the volume gets really ratcheted up!

And cock wrens are not just phenomenal belters out of loud music, they are also amazingly ingenious and frantically energetic house-builders! As an important part of the courtship ritual, the aspiring cock bird will construct a number of nests none of which are necessarily completed, for the benefit of the female, who will inspect this selection of potential nests before settling on the one she likes best. When she has made her decision, she may enter her preferred choice, - the male is of course on hand as she makes her inspections – at which point the bond is sealed and the pairing cemented. Thereafter the two birds will together share the provision of the finishing touches.

The nest is a delightful, domed structure, made of mosses augmented with strands of straw or grass, lined with feathers, lichen and even spider’s silk, with a little entrance hole for access, high up on the dome. The male may build on average, six to eight such nests for her to make her selection, although some particularly energetic birds have been known to build as many as thirty! At first glance, the making of so many nests, albeit in unfinished mode, may seem an unnecessary endeavour, not to say an energy sapping procedure. Well, in truth, these labours do not necessarily go to waste, for once bonding is secured, the little cock wren may well go about advertising for another mate! “Nests available!” is presumably included in his vociferous little jingle! Wrens are often polygamous!

Most nests are sited deep in low vegetation but wrens are nothing if not full of ingenuity. Nests may be built in for instance, in the pockets of old coats or even in hats hung in sheds. Last year’s nest, made entirely of moss and sited in one of my sheds, has already this winter, disintegrated … on my head! There are records of wren nests on the running boards of old lorries and even apparently in a human skull(!) And as wrens, although rather sedentary birds are distributed over such a wide range of habitats from coasts to surprisingly high up our hills, their versatility in finding suitable nest sites is presumably, constantly challenged. However, the proper name for this versatile bird, troglodytes troglodytes, meaning ‘cave dweller’, probably indicates that they were here long before us and our dwellings!

Indeed, the St Kilda wren is thought to have been resident on that far away outpost for some five thousand years. The human population of those remote islands only lasted about a thousand years! And because they are not strong flyers – they seem to fly in the way of some insects, slow and somewhat ponderous – where they have set up home in relative isolation, they have developed in slightly different ways. I certainly remember listening carefully to wrens on almost equally isolated Fair Isle and noting variations in song compared with that of mainland cousins. These wrens, evolving in isolation also vary in size.

Such variations have been noted elsewhere, for instance in Shetland and the Outer Isles. Wrens, being so small, are extremely vulnerable in cold winters. In 1963’s prolonged and exceptionally cold winter, it is thought that the wren population was reduced by some eighty per cent. During the following winter however, this little character exhibited amazing resilience by increasing its numbers tenfold. Because of this vulnerability, wrens often pack themselves in small spaces during cold winter nights, their combined body heat spelling survival. These little examples of what in my young days used to be called ‘sardines’ are the wrens’ means of survival. Again some amazing numbers of wrens, all huddled together in tiny spaces emerge – 30 or more in an old house martin nest, 10 in a single coconut shell and seventeen in an old squirrel drey, among them.

Judging by the hullabaloo of wren song currently echoing across the local landscape – wren voices certainly carry amazing distances – last winter’s benign character has been very much to the advantage of our wren population. These little piping marvels certainly prove that small is indeed beautiful. And somehow, that tiny, cocked tail, gives them that extra bit of character.

Any natural place contains an infinite reservoir of information, and therefore the potential for inexhaustible new discoveries.

Richard Louv, Last Child in the Woods