December 2009
Shelduck - not really a duck at all!

The Shelduck is not really a duck at all, but intermediate between a goose and a duck, such are its characteristics. Although small numbers of this highly attractive duck breed inland, Shelduck are among the most obvious of coastal birds within their preferred estuarine and sand dune habitats.

Around 10,000 pairs breed in Britain, with the Shelduck being widespread around the shores of north-west Europe, particularly around the North Sea. In Argyll, a concentration of this colourful shoreline character is found in Kintyre, but on Mull it is no more than an uncommon breeder , with the largest gatherings being found at Lochdon. Where else on the island can this rather stately-looking duck be found? All sightings would help the Isle of Mull Bird Club build a better picture as to this species status and distribution on the island. Easily recognisable, Shelduck appear "black and white" at a distance, yet closer inspection reveals them to be one of the most glamorous of ducks. Both sexes have a bottle-green head, a generally white body, with bold black horizontal stripes on the back, and a broad chestnut wrap across the breast and upper back. Sexual dimorphism is displayed, however, by way of the large protruberance ("knob") at the base of the drake s bright red beak, which the female lacks. The feathering at the base of the duck s bill is often patchy and white in colour, allowing both sexes to be readily identified in the field.

Shelduck breed where there is an adequate supply of their favourite food, in close proximity to suitable nest locations in rabbit burrows, sand dunes, in buildings and tree holes. In some areas, where suitable habitat may be at a premium, birds mayrequired to re-energise moulting birds, Shelduck are rarely in a hurry to make their return migrations back to their breeding grounds. It is often November before some birds commence their journey back to some Scottish estuaries. In the weeks leading up to Christmas, local Shelduck on inter-tidal mud, such as that at Lochdon and Loch Beg are looking at their best, resplendent in their fresh pied plumage.

This striking duck feeds in a highly characteristic fashion, with small snails comprising up to 90% of their food intake in some areas. With their necks extended, Shelduck sweep their heads from side-to-side, their beaks sifting through the soft, oozy mud in a scything fashion, extracting the small animals that come to the surface as the tide comes in. The stomach of one individual, found dead in Southern England, contained no fewer than 3,000 small snails of a single species, Hydrobia ulvae. This tiny snail is the most important food item of Shelduck wherever it occurs. As such, the life of the Shelduck is governed by the ebb and flow of the tide and, like other birds of the intertidal zone, can be found feeding throughout the day and night, in accordance with the tide.

This distinctive duck is well-known for its spectacular moult migration in late Summer, when most British breeding birds re-locate to join the rest of the NW European population at the Heligoland Bight, off NW Germany. This migration is one of the most fascinating phenomenon in the world of birds. Before any young that they have been raising are independent, adults will fly hundreds of miles to this SE corner of the North Sea, leaving a few aunties at home to babysit creches of youngsters. Around 100,000 birds gather each July-August in the vast sandflats of the German Waddensee, at the mouth of the River Elbe. Here this huge assemblage of Shelduck find the security to moult (the whole flock becomes temporarily flightless), in an area rich in supplies of the small, sand-living molluscs that comprise their main diet.

Stuart Gibson

November 2009
Turnstone.

The Turnstone is a pugnacious and perennial Winter visitor to Mull's foreshore from its breeding grounds in Greenland and/or Arctic Canada. Flocks of up to 40 of these crytically-plumaged little waders return each year, to brave the cold Winter months searching for invertebrates among the rocks and seaweed on shores throughout the island. Indeed, that's how they get their name, as they are industrious birds, forever flicking over stones and other debris with their short, stubby beaks in search of their next meal.

Around 70,000 Turnstones over-winter in Britain each year, and they are a common visitor to rocky beaches throughout Argyll and the Isles at this time. Breeding on the rocky shores and tundra of northern Canada and Greenland, some Turnstones may rarely see human beings during the brief Arctic Summer. This may account for their remarkable tameness and, indeed, many of these birds will entertain a close approach from birdwatchers seeking a better look at these delightful birds.

The party that frequent the Oban foreshore, for instance, seem to have become particularly habituated towards man. It has become an everyday occurrence in Winter for this flock to be seen feeding within a few metres of pedestrians passing by on busy George Street!

In Winter, a Turnstone's feathers are at their dullest, and it is not until Springtime that they moult into their beautiful tortoiseshell breeding finery. This plumage allows the incubating bird to blend in perfectly with the colours of the mosses and lichens found on the Arctic tundra where they nest, affording them added protection against predators, such as Arctic Foxes.

Turnstones tend to live in stable parties of between 20 - 40 birds outwith the breeding season. These parties have a rigid social structure of dominance and subordination, and a tremendous work ethic, based on team spirit. Take an opportunity the next time you come upon a flock locally to stop and watch these irascible little fellows at work. The top birds are those that get to utilise their bills in the most productive fashion, often bulldozing and shunting pieces of seaweed, to reveal hitherto hidden morsels. Lesser birds must perform the drudgery of picking and turning small pebbles or work on the periphery of the feeding area. These tight communal units can be maintained because, like human fingerprints, Turnstones possess a unique pattern on their faces, which allows individual birds to be recognised. It is also possible for human beings to identify individual birds because of their tameness, something which you may wish to put into practice when you are watching these popular visitors.

The first Turnstones arrive back on Mull during August, often as little as 6 - 8 weeks after the last bird left local shores on its northward migration to Greenland. Flocks tend to "disappear" on their Spring journeys un-noticed, although tardy individuals or small groups may linger on the island during early June. By October, the majority of the Winter flocks will have returned, and started going about their industry in a most unobtrusive manner, like only a Turnstone can!

Stuart Gibson

October 2009
Jack Snipe.

The Jack Snipe ranks as one of the most under-recorded of all British birds. Away from upland areas, this diminutive "half-snipe" is a common Winter visitor from its breeding grounds in Scandinavia, Finland and Russia, yet it is a bird seldom seen by most birdwatchers. As many as 100,000 of these tiny wetland waders are estimated to visit our shores each year, yet most go unrecorded, as a result of their secretive habits and cryptic behaviour. Migrant birds start to appear in the Northern Isles (Shetland and Orkney) in August, with the first Jack Snipe being flushed from wetlands in Western Scotland in late September. The peak Autumn arrival into this country occurs during October - November, although a further surge of movement can extend into early December. After this period of passage, numbers of this delightful little wader using local marshes settle down, until a return movement takes place in Spring (late March - early April).

In Winter, it is found at a variety of shallow, wet and muddy areas, usually with plenty of short vegetation: marshes, wet ditches, creeks and field corners, as well as on peat bogs and the upper shores of lochs. Because of its secretive behaviour and choice of habitat, few birdwatchers actively search for Jack Snipe. Consequently, it is rarely recorded on Mull, yet a search of suitable areas on the island in Autumn/Winter would, undoubtedly, reveal more birds than previously imagined.

On being disturbed, Common Snipe let their displeasure be known with a harsh "shcraa" curse towards the intruder. The Jack Snipe tends to be silent on such occasions. However, of 600 birds that I studied in the late 1980's, I heard a quiet "sshhh" being emitted from 35 (< 6%) of them. The "silent" nature of this call makes me think that Jack Snipe may call more often, but are simply not heard.

Jack Snipe feed on insects, worms and snails, which they find by probing their beaks into the mud of the wetland environments they inhabit. They appear less sensitive to frosty weather than Common Snipe, which have longer bills, suggesting that their food is found deeper in the soil than the items taken by Jack Snipe.

Jack Snipe have a rather curious feeding behaviour, as they bounce up-and-down, as if a marionette or a child playing on a trampoline ! This behaviour is not uncommonly witnessed by birdwatchers, especially those that get an opportunity to view these fascinating waders from the comfort of a hide at a nature reserve.

It seems that little is known of the true status and distribution of these mysterious, miniature Snipe in parts of North and North-West Scotland. The Clyde Area has a long tradition of encouraging interest in this beguiling bird among its birdwatchers and, thus, may appear to hold a somewhat disproportionate number of these waders during times of passage and in Winter.

However, conditions in Argyll & the Isles, away from the hills, would appear to suit the likelihood that, for much of the year (October - April), the enigmatic Jack Snipe is over here and over-looked!

Stuart Gibson

September 2009
Hen Harrier.

The graceful "Seagull Hawk" is something of a major league player with birdwatchers on Mull, among both residents and visitors to the island. The sight of a grey male or a ring-tail female coursing rough grazing or moorland is a joy to behold and has the making of any observer's day on the island.

The Hen Harrier has always suffered mixed fortunes at the hands of man and is still subject to illegal persecution in some areas of the country, where it is charged with disturbing sporting interests and killing game birds (mainly Red Grouse) and their young. A largely unknown, but thought only small and isolated population of Red Grouse breed on Mull and there are no keepered moors on the island, where the interests of game birds are protected above anything else. As such, the several pairs of Hen Harriers that breed on Mull appear to do so unmolested.

In previous centuries, the "Blue Kite" was common and widespread throughout much of the British Isles, but land use changes during the agricultural revolution and direct destruction from gamekeepers in Victorian times brought about a dramatic decrease in the numbers of this beautiful raptor.

For the first half of the 20th Century, the Hen Harrier's range in Scotland was largely confined to Orkney (where it still maintains a stronghold) and the Outer Hebrides. Since the 1960's, suitable nesting areas on the mainland have been re-colonised, although it hasn't been until much more recently that the relative prosperity of this "White-rumped Buzzard" has changed for the better in some places. It should not be forgotten, however, that less than 600 pairs of this spectacular bird of prey are to be found on the moors of Britain and Ireland today; a statistic that makes the Hen Harrier only marginally more common than the Golden Eagle (431 pairs)!

The year-to-year status of this magnificent raptor on Mull appears to be correlated with the relative abundance of its main prey - small birds, like Meadow Pipits and small mammals, such as voles, which are the Hen Harrier's preferred meal. Meadow Pipits are altitudinal migrants, with many leaving the island in Autumn, while the local vole population is subject to cyclical peaks and troughs. Consequently, Hen Harriers remain resident on Mull in some years, but effectively occur as a Summer migrant (Apr. - Sep.) in others, particularly when vole numbers on the island are low.

Dispersing away from their breeding haunts, roaming Hen Harriers may turn up anywhere on the island during the Autumn and Winter months, but any area of low-lying rough grassland or young conifer plantation may be favoured e.g. at Fidden, Glen More and Lochdon.

Watch for the "Moor Hawk" displaying its distinctive hunting technique, which consists of low and slow quartering, systematically checking every tussock for the slightest movement of a small rodent. On spying a mouse or vole, the bird will turn on a sixpence and, with outstretched talons, drop like a stone into cover, where it may remain for some time, as it consumes its unfortunate prey.

 

Stuart Gibson