Nightingales in November (61 page)

Early November

Having led the charge of the winter visitors for some time, the population of Lapwings in Britain could easily reach over 600,000 by the time November finally arrives. Impressive though this figure might sound, it is, in fact, the lowest it has been for at least a generation and is a sad reflection of an alarming decline in the breeding success of this charming farmland wader not just in Britain, but right across northern Europe too. Lapwings have become one of the most notable victims of the large-scale agricultural intensification in the countryside, as heavily managed crops and high stocking rates of cattle give little opportunity for wildlife to coexist alongside such modern practices.

As both continental and British Lapwings roam the countryside to take advantage of any foraging opportunities, the size of these feeding flocks will invariably depend upon the amount of food available. Within the landscape, these flocks also tend to be highly clumped, with many fields remaining untouched, while others are used intensively. Lapwing expert Michael Shrubb carried out research into Lapwing field-use during three successive winters in Sussex, and found that only 40% of the 111 fields in his study area were ever visited, and just nine fields were used regularly. As good feeding is obviously distributed so patchily, the Lapwing must therefore operate both collectively and effectively in order to track down the best sites, in the full knowledge that when good feeding is found, there should be more than enough to go around.

Upon the flock's arrival at a rich feeding site, it will then be down to each individual Lapwing to forage for itself. Lapwings have large eyes relative to their bill size and tend to hunt primarily by sight. The feeding technique most frequently adopted is known as ‘pause/travel feeding' and consists of a few steps, followed by a pause, a scan, and then a move forward to either stoop for a prey item, or to repeat the process if nothing is spotted. Despite this being considered an effective method, not all scans locate prey and not all strikes are successful. When found, the prey will then be prized from the soil by the Lapwing's short bill. In contrast to many of the long-billed waders, such as curlews and godwits, the Lapwing's bill doesn't have a sensitive tip capable of locating food by touch, but is instead hard and horny for grasping and holding the prey. Most of their diet seems to consist of carabid and staphylinid beetles, millipedes, slugs, leatherjackets and earthworms, with the food taken varying seasonally according to the annual life cycles of prey organism. Also the weather conditions will affect the state of the soil, with earthworms, for example, travelling deeper and in the process becoming far more inaccessible in the dry heat of the summer and autumn sun.

Another advantage of flocking, in addition to sourcing patchily distributed food, means that there will be many more pairs of eyes looking out for predators, but one obvious downside to sharing a ‘dining table' with so many others means that squabbles between individual birds in too close a proximity will often become inevitable. In denser flocks, aggressive interactions are recorded more regularly, resulting in territorial displays perhaps more commonly associated with breeding grounds also being observed on the Lapwings' winter territories. Two evenly matched birds arguing over a feeding spot will often resort to parallel walking along an invisible boundary as they size each other up. If the dispute isn't quickly settled by the equivalent of this staring match, then it can quickly escalate into hunched
or crouched running, jumping up at each other and ultimately fighting.

Continuing to arrive at their traditional overwintering sites such as Slimbridge in Gloucestershire, the Bewick's Swans will also find that a rapidly increasing flock density will initially cause a huge amount of consternation in the ranks until a pecking order finally becomes established. Containing all social groups, the wintering flocks of Bewick's Swans will include families, pairs without cygnets, single adults and yearling birds. When it comes to forming the dominance hierarchy, numbers and experience will count for everything. Disagreements will initially be addressed by ritualised behaviour, but can quickly escalate if neither side is willing to back down. The first sign of a dispute may consist of nothing more than a head lowered in threat, or a well-placed peck, but if these are ignored, then the Swans will enter a well-choreographed and established routine which increases in intensity with each step. The male is invariably the most common protagonist in these aggressive encounters, and after starting with neck stretching and head pumping, he will quickly move through the gears in his threatening repertoire. Starting with extending his wings to a half open position, he will then ramp up the threat to progressively higher levels, to include wings being half open and flapping, wings then fully extended and flapping and finally wings fully extended and still. If by this stage his opponent is still not willing to concede defeat, then the behaviour may quickly descend into a fight with the aggressor biting while beating his wings, in the full knowledge that his family will be noisily lending support in the wings.

As subordinate single swans will tend simply to give way to the more dominant birds or family groups within the flock, this final ‘nuclear option' is generally only reached when opposing parties are well matched. Submissive behaviour will
usually resolve the matter and involves the defeated bird turning away with its bill tilted up so it can clearly guard its rear while beating a hasty retreat. Any successful aggressive encounters are usually followed up with ‘triumph' displays, in which the winning swan will return to his mate and cygnets, before displaying with a neck stretching, wing flapping and loud honking routine as his family enthusiastically joins in the celebrations. By always keeping no more than just a couple of wingbeats apart when in amongst the wintering flock, the dominant families will always have muscle on hand to take the pick of the best foraging and roosting spots for the entire duration of the winter. In fact at locations like Slimbridge, where many of the swans will return each winter, this hierarchy can become so entrenched that dominance will frequently be held from year to year.

Freshly arrived from northern Europe, any aggression between individual Waxwings from the same flock only ever seems to be minimal as these gentle birds adopt a far more consensual approach to feeding than the obstreperous Bewick's Swans. Where Waxwings go after their initial arrival is now more clearly understood thanks to work carried out by colour-ringing studies. By ringers using different colour combinations on the legs of each Waxwing netted, birdwatchers up and down the country are then able to report the location of different individuals without the need for their recapture. During the influx of 2010/11, for example, the Grampian and Orkney Ringing Groups managed to catch and individually colour-ring almost 500 Waxwings through late October and November in an attempt to try and track the movement of the birds as they spread across Britain. With competition for berries patently at a premium, Waxwings quickly departed both ringing locations, with one particular Orkney-ringed bird rapidly relocating to Norfolk and a number of
Aberdonian-ringed Waxwings subsequently reported from Dunfermline, Lothian, Glasgow, Cumbria and Manchester. The subtleties of each Waxwing invasion will of course play out differently, but the general pattern of movement usually sees birds streaming in a southerly and westerly direction as the food becomes stripped out of their original entry points. Interestingly, one of the Waxwings caught in Aberdeen was an adult male that had been ringed in Svartbyn, a town in northern Sweden, close to the Finnish border. After having travelled 1,654km all the way to Duthie Park in Aberdeen, this bird then sadly proved to be a window casualty just a week later, but only after having served as a standard bearer to further illustrate the strong Waxwing link between Sweden and Scotland.

The Swallow's link between Britain and South Africa was first established over a century ago, when a female ringed in Staffordshire in 1911 was subsequently recovered from the Province of Natal in December of the following year. This was merely the first of an astonishing 447 British-ringed birds that have so far been recovered in South Africa, patently making the southern reaches of the African continent their destination of choice. It's believed that most returning Swallows will generally be faithful to their winter quarters, although locations can vary if the weather impacts on food availability. Just as in Britain, the Swallows will forage across a wide variety of habitats, as they swoop over grassland, forest edge, cultivated fields and particularly any wet environment, before then returning each evening to their communal roosts.

Up to 2011, not a single ringed British-breeding Nightingale had ever been reported south of the Sahara, leaving the sum total of knowledge about the location of ‘Nightingales in November' to be collated from the information gleaned
by the geolocator attached to ‘Nightingale OAD'. As geolocators have an inherent degree of inaccuracy in the tropics, where dawn and dusk vary little throughout the year, the BTO researchers interpreting the data believed OAD most likely to have been passing through Mauritania in early November. Comparable in size to Egypt, around 90% of this huge but impoverished country is categorised as ‘Sahara Desert', with most of the population living in the south-west, which experiences a marginally higher rainfall than in the desert interior. Despite a substantial mineral wealth consisting of significant deposits of iron ore and oil, severe international sanctions following a coup d'état in 2008, a poor human rights record and corruption have all combined to ensure that Mauritania remains a desperately poor desert nation.