Weekly Nature Watch

Weekly Nature Watch 18th December 2020

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A rare golden December afternoon sky ensures that the waters of the loch are also gilded for there is not even the slightest hint of a puff of air to ruffle them.

No breeze, perhaps, but plenty of movement to disturb that mirror image for the water's surface is reminiscent of a busy shipping lane. Often have I enjoyed the experience of flying over busy shipping lanes like the English Channel and seen the herring-bone patterns reaching far across the waters before gently subsiding as ships of every shape and size cleave their way through the waves.  The loch also resembles a shipping lane but here there are no ships, just busy clusters of waterfowl buzzing their way over that golden surface and diving beneath it.

In between the herring bone patterns and sometimes at the very apex of them, suddenly there is a plop followed by an expanding series of concentric circles as an exploration of the darker waters below the surface takes place. The considerable number and variety of ducks these waters support generally falls into two categories - those that dabble, feeding largely on surface material and those that dive to explore the hidden depths for a wider selection of food.  

Mallard ducks are the dabblers and groups can often be seen head dipping or completely upending in the water.  However, they rarely dive spending their time near the surface and dabbling for invertebrates, fish, amphibians, and a variety of plants. They also graze on land, feeding on grains and plants.

Thought to be the most abundant and wide ranging duck on earth and clearly the ancestors of many domestic ducks, they are a familiar sight to many people.  The drake is the more distinctive of the mallards. Its iconic green head sits atop a white neckband that sets off a chestnut-coloured chest and grey body.  Females are a mottled drab brown but have iridescent purple-blue wing feathers that are visible as a patch on their sides.

But today it is the diving ducks that catch the eye and there is also gold here for two of the most familiar of these submariners are characterised by their golden eyes. One is an all-year-round resident, the other a visitor from the far north - in some cases the very far north. The latter is, of course, the appropriately named ‘goldeneye’, a resident in summer of such faraway places as northern Scandinavia and Siberia and a duck which, perhaps surprisingly, chooses to nest in trees. Wintering birds arrive here from August to December and return north in February and March.  However, in recent decades, a handful of goldeneye has remained in Scotland for the summer, perhaps in some cases encouraged to remain and breed as a result of the provision of nest boxes although, in these parts such boxes appear to have attracted only tawny owls!

The goldeneye drake is a black and white bird with white predominating especially along the water line, but his most prominent features are the bold white cheek patches, the abnormally square head and high forehead and a golden eye. Although the impression of the bulbous head of the male is that it is black, in bright sunlight, it has a dark green sheen. In comparison, the duck is plainer, greyer, with a russet brown head rather than a black one but also has the same golden eye.  

Goldeneye are especially renowned for their ability to dive deeper than most other wildfowl and they may sometimes remain underwater for as much as a minute at a time.  In fact, at one time it was thought that the bird was able to do this because of the presence of air pockets within its large skull - a rather doubtful supposition, I fear. They seek food by turning over stones on the bed of the loch in the hope of finding small crustaceans or other forms of invertebrate life.

There is a precocity about goldeneye, typified by their exceptionally early courtship displays which often begin in the very depths of their winter sojourn here. The strange antics performed by the fervent drakes are mildly amusing to observe with the drake usually paddling round the female, his head feathers puffed out to make his head look even larger, his tail pointing skywards and his head and neck stretched forward. Often this is followed by a thrusting of the head backwards and at the same time a kicking up of water to the rear.  However, there are several variations on a theme and the drakes seem to get themselves into a real lather, while the ducks give the impression of complete indifference.

The other golden-eyed diver, one that is more universally familiar due to its lack of shyness and its often presence on urban located waters including park ponds, is the tufted duck which breeds throughout temperate and northern Eurasia. They are migratory and overwinter in the milder south and west of Europe and southern Asia but are present throughout the year in the British Isles.

Smaller than the mallard, the adult male is all black except for white flanks and a blue-grey bill with gold-yellow eyes, along with a thin crest on the back of its head and an obvious head tuft that gives the species its name. The adult female is brown with paler flanks, and is more easily confused with other diving ducks. It is hardly surprising that the tufted duck shares the colloquialism of ‘douker' with the goldeneye but this is an altogether less demonstrative bird compared with its more flamboyant fellow submariner. Indeed the tufty, sometimes called the ‘blue neb’ from the colour of its bill or the ‘magpie diver’ because of its black and white plumage, with black being the predominant colour in this case.

This is a much more sedentary creature altogether but it too is renowned for its diving ability. If not quite able to match the goldeneye for depth or duration of dive, it is not very far behind in the ratings, often staying underwater for as long as 50 seconds and also reaching the bed of the loch to turn over stones.  The tufted ducks feed mainly by diving, but they will regularly upend from the surface. Their food consists of molluscs, aquatic insects, plants etc., and the birds will sometimes feed at night.

Fittingly, it is not only much less ambitious when it comes to courtship displays but it is also much more conservative when it comes to nesting. Not for the tufted duck the ambition to nest high in a tree. They prefer to have both feet on the ground, generally close to water, the nest merely a hollow filled with grass. As a result, tufty ducklings are spared the indignity and potentially damaging exodus from their nest that is a fall of several feet either on to the ground or occasionally into water if they are lucky, experienced by goldeneye ducklings.

As the winter sun dips ever lower, so are the spreading circles created by these submariners each time they dive beneath the golden surface etched more starkly, blacker and blacker with each dive. Otherwise, the water and the eyes remain pure gold.

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

Richard Louv, Last Child in the Woods