Am Bratach No. 255
It was a day I shall always remember. The Scandinavians had arrived during the night. First a few, then small groups of twenty or thirty, then larger groups of 100 or more and now at midday there seemed liked thousands. As I climbed out of the car, I could hear the chattering all around me. It was probably the most birds I had ever seen in one place in Assynt. I remember the top of a particular spruce tree nearby had a lot of dead branches and they were covered in birds coming and going. There was simply not enough space for the arriving birds to land. Every now and then the chatter would intensify and then there would be a whirl of wings and a blur of motion and another flock would cross to the other side of the glen. How many do you think there are? David asked. But how do you count something like this? The whole wooded hillside seemed to hide more and more. It was the day the waxwings arrived.
Natural phenomena such as this always has a cause, which maybe far away. In this case the waxwings had had a good breeding season in their home regions of Scandinavia and Northern Russia. However, the weather there had now turned nasty and a cold east wind had blown in and there were not enough berries to keep them going. An irruption of waxwings started. Typically, we can expect an irruption about once every six years. The birds usually arrive on the north and make their way down the east coast. If abundant food does not halt their progress they can reach as far as Cornwall devouring all the berries they can find: rowans, cotoneaster, hollies, even privets. The last waxwing winter was in 2010/11 when hundreds started arriving in Shetland.
But this year was different they moved down the west coast. The waxwing telegraph system must have been working well because when they arrived in Scotland they seemed to know the west was best. We have had just about the best year ever for rowan berries. The woodlands have been spectacular this autumn with autumn colours and the cream on the landscape cake has been the rowan trees bursting with a bountiful bonanza of bright red berries. I have never seen our rowan trees so completely laden with berries. While some will tell you it is a sign of a coming hard winter, it is in fact a sign of a glorious spring. Indeed if you remember when the rest of the country complained of rain and dampness we basked in glorious sun the whole month of May and early June. The strong, sweet scent of the creamy flowers of the rowan tree would have attracted pollinating insects, including many species of flies, bees and beetles ensuring a a good crop of berries in the autumn for our Scandinavian visitors.
If you missed them, waxwings are about the size of a starling but salmon pink in colour. If you see them close up you would think they are the most exotic bird you have ever seen. With luxuriant hat-like head crests and black bibs, they have a black mask like lawless highwayman loitering with intent. They have dabs of bright colours on their wing and their tail looks as if it has been dipped in the most brilliant yellow gloss paint. Indeed, the name waxwing comes from the bright red tips on some of their wing feathers which look like drops of red sealing wax that was used on envelopes and letters. As the bird gets older the wax tips gets even larger and bolder. Their full title as befits such a charismatic bird is Bohemian waxwing in reference to their erratic and unpredictable nomadic behaviour during winter.
Invasion years have been noted as long ago as 1685 when Gilbert White referred to them as German Silk-tails. There have been eighteen notable invasion years since 1937. Possibly the largest was in 1946/47 when at least 12,500 birds were recorded. Flocks, as large as 1,000, were recorded. This year in Strathan, outside Lochinver, we reckon there was a flock of easily 500 and maybe more Bohemian waxwings together with about 2,000 fieldfares along with a few redwings, Scandinavian song thrushes and blackbirds. But even in this melee of birds the waxwings stood out due to their constant high pitch chattering a rapid buzzing trill of sharp notes which almost sounds like a tiny bell.
It was amazing to watch them eating. For no apparent reason to us, they would choose one particular rowan tree within the woodland and the first squadron would descend and eat their fill and then move out of the way for the second shift to fly down. They would then move away for the next and so on. That way these highly sociable, co-operative birds shared the food equally between them. Once that tree was stripped bare they would target another, perhaps on the other side of the road. A flock of birds that size can be ravenous. It is said that one bird in Wales ate 600-1,000 berries, perhaps four to six times its own body weight in six hours. At that rate our flock in Strathan could have been eating a third to half a million berries a day.
Just as remarkably and hardly surprising the birds will defecate every four minutes. Now, I know the ecology of dung is not the subject for everyone, but rowan trees have tempting red berries for the very reason to attract birds (as well as mammals such as the pine martin). Remember that once the birds have eaten the berries along with the seeds, they will often travel a considerable distance from the tree before excreting the seed, complete with a package of fertiliser! I look forward to next spring when I expect rowan trees to be springing up everywhere.
But as quickly as they arrived they went. The Highland Ringing Group wanted to come and see if they could catch some of them, but it was too late. Yesterday I saw a solitary bird fly along the main street in Lochinver. Left behind by his mates, with all the berries gone, it looked rather frantic. Perhaps it had just got drunk on all those ripe and fermenting berries and woke up this morning with a hangover.
Andy is a senior Highland Council countryside ranger, based at Lochinver.