Weekly Nature Watch

Country View 13.4.16

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There are those who are hooked on insects and who study them in infinite detail. On the other hand there are those who regard most insects as little more than nuisances and pests. Yet, whether you hate or love insects, they are the very essence of life. They are for instance, pollinators and thus are not just important but indeed vital to our very survival. They are also of course, vitally important as the main source of food for millions and millions of birds, especially those currently on their way here as summer migrants.

Indeed, most of the birds currently en route from Africa to Northern Europe are utterly dependent upon insects as their sole source of food. I have on those few really encouraging days that truly signal the advance of spring, seen plenty of evidence of emerging insect life, albeit that the current prevalence of easterly winds has probably put the brakes temporarily on further ‘blooms’. And yet, rather late in the day perhaps, I have at last heard the first monotonous tones of newly arrived chiff-chaffs. Here is a minuscule bird – a warbler of course – which is always one the earliest of the mass of birds to arrive after that astonishing migratory journey from darkest Africa! And, chiff-chaffs feed exclusively on insects!

I must confess that chiff-chaffs are not exactly exciting, either to listen to or indeed, to look at. Yet the evidence of their presence does cause the heart to beat that little bit quicker for they surely confirm absolutely that spring is with us. But they lack the glamour exuded by the likes of swallows and martins. Many folk of my acquaintance regard the house martin and the swallow as the true summer birds and with the wind still blowing in from the east (all the way from Siberia perhaps?) there is as yet, unsurprisingly, no sign of them. But there is a third member of this clan, the sand martin. On examination, although it is relatively unobtrusive and accordingly less glamorous than its better known cousins, in flight it is extremely adept.

And, there they were, skimming low over the waters of the loch, which were well ruffled by that biting easterly.  If I could see them dodging the waves, I could not, of course, see the hosts of insects they were so energetically pursuing. The newly arrived martins were obviously filling their little stomachs with them. Sand martins may not be quite as glamorous as their ‘up-market’ cousins but my word they can fly! They are earth brown in colour, ‘dirty’ white underneath, with a greyish brown necklace separating the white of the throat from that of the belly.

As I scanned the waters, to snatch brief glimpses of these aerial insect predators, another bird crossed my field of vision. This was rather easier to follow, for instead of dodging the waves, it was bobbing on them! The great crested grebes have probably been back on the loch for a few weeks now for they are not long distance migrants like the sand martins. Instead they spend their winters off shore probably on the icy waters of the North Sea, a rather harsher environment than that sought by the sand martins in tropical Africa! If the martins were earning their living above water, the grebes instead, depend on what is beneath the water.

Many years ago, I used to regularly make my way on summer days to a wee lochan where, lying on my stomach high above this crystal clear hidden gem, I could watch the grebes doing what grebes do best, swimming under water. If grebes, because their legs are set so far back on their bodies, are ‘out of their depth’ so to speak, when on terra firma, they are absolutely in their element as sub-mariners. In those clear waters I could watch every sinuous movement, every surge they made in their unremitting search for small fish, with absolute wonder. If they are known rather unkindly as ‘arsefoots’ for their clumsy disposition on dry land, they are otherwise more kindly called ‘doukers’ or ‘crested doukers’ for their exploits in or under water.

Great crested grebes are lowland birds, seldom disporting themselves on or in less fertile Highland lochs, which is precisely why at least seven pairs regularly grace these local waters, just south of the Highland Line. There was a time, when these remarkable birds were a real rarity, for during the nineteenth century, when the fashion icons of Victoriana demanded the use of feathers as decorations for hats, the head and neck plumes of the grebes were so much in demand that the grebe population collapsed. By 1860 it was estimated that there remained in the whole of Britain but 42 pairs of these lovely birds!

It wasn’t just those head and neck plumes which by the way, look an awful lot better on the grebes themselves than on hats, for the body plumage too was so thick and of course, waterproof, that it was known as ‘grebe fur’, which was accordingly also very popular with the fashionable clothing industry of that time. Thankfully, before it was too late, the politicians were alerted to this crisis and introduced successive parliamentary bills as a means of protecting among other birds, the endangered grebes. As was in those days, always the case, it took time for the legislation to be effective and the recovery of the grebe population was slow. Indeed, by the nineteen thirties, there were still only around 1,300 grebes recorded throughout Britain.

In the early twentieth century, great crested grebes hit the headlines for an entirely different reason, through the remarkable work of Thomas Huxley whose study of the remarkable courtship displays of these enigmatic birds came to be regarded as a truly seminal work. These courtship displays are indeed amazing to behold with both male and female offering gifts of water weed to each other, as face to face, breast to breast, they rise until they seem to be walking on water!  There is much head shaking and some loud and to our ears, coarse calling. Huxley’s work was and still is regarded as unique in the field of animal behaviour.

Happily the grebe population was further boosted during the 1930’s due to a rapid expansion in road and house building which required much sand and gravel. As a result, the creation of many so called gravel pits, duly filled with water which were apparently tailor made for grebes saw the beginning of a real recovery in breeding numbers! Strangely enough, sand martins too shared in this unnatural expansion of suitable habitat, the steep sided often sandy banks of these new ‘ponds’ ideal as nesting sites. Two quite different species then, enjoying the benefits of human activity!

Both provide further confirmation of the season’s progress and both in their own distinctive ways, add a particular kind of animation to the gathering sense of excitement as the season of re-birth really begins to gather momentum.

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

Richard Louv, Last Child in the Woods