Even as I write, countless birds, little more than fragments of feather, bone and sinew, are making their way here from darkest Africa, as thousands, millions and even billions of them undertake their springtime migration; surely one of the true wonders of the world.
Bird migration on a large scale has been going on since the Ice Ages of thousands of years ago, the vast populations of insect eating birds driven ever southwards as the ice advanced during successive winters. Then they must have flooded back northwards with each spring as the ice retreated allowing those insect fragments of life to prosper again encouraging the hordes of birds back north for the summer months. This has become the inescapable rhythm of life for countless migrating birds. The miracle when millions of birds forsake their wintering grounds in Africa and head inexorably north is under way and as these next days and weeks come and go, so hosts of these intrepid travelers will also arrive.
The early birds have already arrived for there it was, unmistakable in its simplicity, the two-note signature tune of a chiff-chaff and, for me at least, the true herald of spring. So often, the chiff-chaff is the first of these long-distance voyagers to reach our shores. He is recognized by the monotonous song that easily singles him out but in a few weeks, we will be celebrating the arrival of his look-alike cousin, the willow warbler, distinguished by the subtle difference in the colour of his legs which are lighter than those of the chiff-chaff and more or less flesh coloured rather than black. Not that we get sufficiently good sightings of either of these birds to identify them readily by their leg colour. Vocally, the willow warbler is also more ambitious with a silvery, down the scale song.
Both birds are inclined to hide themselves away in thick vegetation or high in the canopy and both build their nests more or less on the ground in such vegetation. Curiously the chiff-chaff is known as featherbed in one part of England, a reference to the little dome-shaped nest they build. Yet in this case, local folklore has got it wrong for the chiff-chaff seldom uses feathers to line its nest whereas the willow warbler does. A case clearly of mistaken identity for the author of this pseudonym clearly didn't look at the colour of the bird's legs!
With the wind turning into the north and east, I'm afraid the insect life upon which the newly arrived chiff-chaff depends is likely to be pretty sparse, albeit that the other day I saw a column of gnats displaying in my garden. All of these warblers largely exist by scouring the vegetation for insect life and although I have yet to see persistent evidence of emerging insect life, I'm sure that they will appear during these next few days and weeks. Nevertheless, those hosts of warblers are inexorably heading our way and I expect that the progression of life will ensure the emergence of plenty of insect life to sustain them.
If the monosyllabic chiff-chaff denotes the first arrivals of spring migrants, I always feel that the sweet little ditty of the willow warbler underlines the true arrival of spring confirming, as Ted Hughes wrote of the later arrival of swifts which means the globe's still working. The annual cycle is indeed still happening as the lonesome osprey sitting atop his eyrie patiently awaiting the arrival of his mate and the solitary voice of that chiff-chaff confirm that the wheels are indeed still turning.
However, for all their differing musical styles, except for a tint of green which means they are not just ordinary little brown birds, the warblers of this world are not outstanding beauties. Rather are they relatively plain Janes. Yet their music is at times remarkable. As already stated, the willow warbler's cadence down the scale is sweet and silvery whereas the trill of the wood warbler and the sometimes, coarse notes struck by sedge warblers, although less tuneful, are also signals that the world is still turning. The most amazing vocal offering by any warbler must be the astonishing ventriloquism of the grasshopper warbler which trills away whilst turning its head this way and that so that its voice is thrown and literally comes and goes in the most incredible way. Perhaps the sweetest of the warbler vocalists is possibly the garden warbler although the blackcap is tuneful too.
Cuckoos - their numbers are falling dramatically - will also be making their way here from deep in Africa, although they don't really make their presence felt in these parts until May. And of course, also winging their way towards us will be the swallows and martins. Sand martins are among the early arrivals and soon I shall be scanning the waters of the loch in the hope of seeing them skimming over the surface in their ceaseless search for insect life.
The swallows, which also usually arrive here during this spring month of April, fly an incredible six thousand miles from the Cape of Good Hope on their migratory trip. They, I always feel, bring the true essence of summer when they arrive. But pause for a moment to remember that there are even longer journeys undertaken with Arctic terns flying the entire length of the globe translocating from one end - the Antarctic - to the other - the Arctic - in a marathon migratory journey.
Manx shearwaters almost go one better. These secretive birds, that breed on the islands on our west coast, fly off to waters lapping the shores of South America and then, using the Gulf Stream as their guide, cross the Atlantic again to return in the spring. Theirs then is also a journey which sees them move across the globe as well as north to south.
That lone chiff-chaff is therefore the first of the many birds, little more than feather and bone, that put their lives at risk the minute they embark on their astonishing travels. However, there is a group of migrant birds that will be leaving us this month. Soon, those great skeins of geese will depart for more northerly climes in the Arctic where they will maximise the short Arctic summer to rear another generation of their kind. The whooper swans too will leave us with a similar itinerary. Woodcock, short-eared owls, crossbills and goldcrests et al will flood back across the North Sea to a Scandinavian summer.
Our understanding of bird migration was preceded by any number of imagined theories. For example, it was firmly believed by even eminent naturalists that swallows hibernated in the mud at the bottom of lakes and lochs. This supposition was based upon the spectacle of migrating swallows choosing to roost in reed beds overnight, moving on before daybreak the following day. Another theory was that cuckoos transmogrified themselves into sparrowhawks for the winter, a theory based on a similar profile shared by both species and the fact that during the summer sparrowhawks, virtually disappear, hiding away in vegetation where they lay ambushes for other small birds.
Only in relatively modern times, now aided by bird ringing and technology such as GPS, have the true facts of the mass migration of birds across the globe emerged. The consensus is that it is surely the nearest thing to a miracle that nature produces!