by Mike Dilger
With the Swallows travelling the furthest back to Britain of our three summer visitors from Africa, it’s no surprise that they are also the first to peel away from their wintering grounds. With males invariably arriving in Britain as much as a week earlier than the females, early February will see the very first males begin their migration, but it won’t be until later this month that the majority of birds will leave. Roosting communally by night in reedbeds or other wetland vegetation, some sites in South Africa can contain huge numbers of birds.
One particularly well-known location for roosting Swallows are the reedbeds at Mount Moreland in the province of KwaZulu-Natal in eastern South Africa. Despite the fact that most of our Swallows are considered to winter further west in the Western Cape, there will doubtless be British birds mixed in amongst the flock of up to three million that fly in half an hour before sunset after a day’s feeding in the surrounding countryside.
From the BTO’s work satellite-tracking Cuckoos it seems the majority of British-breeding birds in early February are still in their regular winter feeding grounds at a variety of locations centring on the Congo River. With no more than a few weeks before they begin their long and winding route back to Britain, it’s important that they use this time to feed well and ensure they’re in the best possible condition for the huge journey ahead. Likewise, our British-breeding Nightingales will still be ensconced in their winter quarters along coastal regions anywhere between Guinea and Sierra Leone. During the winter the males are thought to occupy small territories until they finally leave in mid-March, quickly returning to Britain in a series of very long hops.
Mid-February
With a typical lifespan of six years, and the oldest known bird reaching the grand old age of 17, an established pair of Peregrines may well be able to hold on to a good territory for at least three or four breeding seasons. Nevertheless, an intimate knowledge of one another will not preclude them from reaffirming their bonds in the most spectacular of ways each February. With last month’s co-operative hunts served up as little more than an hors d’oeuvre, the main event will begin to see the pair conducting high-speed chases. Stooping at one another with increasing enthusiasm, the pair can build up to a truly dazzling display. For any town or city hosting a pair of urban-nesting Peregrines, a fine day in the middle of February may well see the birds tearing across the cityscape, in behaviour that is only slightly modified from the basic techniques used for hunting and territorial aggression.
While perhaps not quite as flamboyant as the Peregrine’s way of declaring ownership, the male Blue Tit’s song is an equally clear statement of intent to any other males in the neighbourhood. On fine days in mid-February a male Blue Tit holding territory will spend a large portion of daylight hours endlessly repeating his simple song to all willing to listen. His song will only be heard less frequently once the boundaries between all his neighbours have become clearly demarcated. Additionally, it’s thought each male will come to quickly recognise the distinct songs of their respective neighbours. This means that if a newcomer attempts to barge in by suddenly adding his voice to the chorus, he will instantly stand out. With this unknown male potentially upsetting the stability of a settled community, all the surrounding Blue Tits will immediately take to their perches to send the message loud and clear that the intrusion is an unwelcome one. Any pair without a nesting location nailed down by this stage will begin prospecting potential nest sites. So, from this time, any Blue Tits spotted popping in and out of various garden nest boxes will be obviously shopping around in a ‘try before you buy’ policy.
By now most Robins should have secured both a territory and a partner, and with these two essential prerequisites in place, it might seem that they would be keen to move on to nest building, but this doesn’t seem the case. Stalling any progress, the pair then enter an extended ‘engagement period’ for a few weeks. During this time, the male and female seem to virtually ignore each other and, despite staying in the same territory, are seldom seen together. The female at this point tends to become shy and retiring and the male takes to singing again, making clear that the territory is still very much occupied. Despite the male’s ambivalent attitude towards his mate at this stage it is patently obvious that he can recognise her from a distance, otherwise his über territorial instincts would kick in and he would treat her as any other trespassing Robin – in other words, drum her out!
With the weather still able to rapidly take a turn for the worse at this stage, a cold snap may be enough to briefly separate the pair, which will then revert back to their individual territories, only moving back together once the weather improves.
Breeding is at a much more advanced stage with most Tawny Owls, however, and with eggs generally laid in early March the female will now not venture far from her chosen nest site. Naturalist Dave Culley has spent hundreds of hours watching Tawny Owls nesting close to his home, and with the help of infrared cameras has been able to film behaviour rarely, if ever, seen before. Dave thinks this is the key period when the female will start to rely heavily on the male to supply her with sufficient food to acquire the necessary reserves for the rigours ahead. After dusk, from mid-February she will be constantly badgering her mate to begin the night’s courtship feeding, supplemented with any food that she herself might be able to catch close to the nest site.
Also working hard to ensure their mates will be in as good a condition as possible will be the male Bewick’s Swans. Amongst family parties, the obvious benefits to being dominant include access to the prime feeding areas and best roost sites, but maintaining a commanding position in the social hierarchy can also be physically demanding. At this stage of late winter, while the females continue to put on weight in preparation for both their long flight and egg laying, their partners will have often lost considerable condition as a result of putting the well-being of their families ahead of their own. It’s at this stage of the year that researchers from the WWT are able to distinguish those birds that have put down the most fat reserves during the course of the winter. In slim birds, which are probably lower in the social hierarchy and last to feed, their vents (or bottoms) will look slightly concave, but the vents of well-fed birds appear much fuller, with the appearance of a ‘double bulge’. In the world of Bewick’s Swans, it seems a ‘big behind’ means you’ve wintered well and should carry you in good stead!
Having been happily solitary all winter, male Kingfishers will often find that the beginning of the breeding season can be a touch uncomfortable as they become accustomed to a newly arrived female. The early stages of courtship can tend to look quite similar to the threat display that Kingfishers on territory will adopt if a trespasser comes on to their patch. Announcing her presence by calling, a female’s technique is to perch close to her prospective mate. This elicits an immediate response, which sees him standing upright, dropping his wings and positioning himself in such a way that she is able to see the full extent of his dagger-like bill. If the match is deemed compatible, he may then begin to make soft wooing whistles, to which she will respond with a similar call.
While male and female Kingfishers become acquainted with one another, by mid-February British Lapwings will also begin arriving on their breeding grounds. Lapwings seem to be highly faithful to the same sites year after year, and certainly in northern England have been found to nearly always return to identical or neighbouring fields. Their spring arrival is initially fairly unobtrusive, with the first parties back often preferring to feed on fields close to the ultimate breeding territories as they doubtless gauge the lie of the land. The males generally tend to arrive a week or so earlier than the females, who prefer to stay away from the melee until the territories are carved out. Preferring to visit the breeding grounds initially at dawn and dusk, the males will then tentatively start displaying, with moonlit nights often proving popular.
Those Lapwings of continental origin will begin to return to their breeding areas at this time and one of the most unexpected aspects of
Lapwing migration is that, although most British-bred Lapwings will return to where they hatched as chicks, a few of these ‘British’ birds will undertake ‘abmigration’. Abmigration is considered a northward (or north-easterly) migration, without a corresponding southward (or south-westerly) migration the previous autumn. The fact that some Lapwings seem to go in the opposite direction to what might be expected is only known because the BTO has recorded a number of Lapwings ringed as chicks in Britain which were then subsequently found breeding in countries as far away as Russia. In these cases it is suspected that British birds may well have simply migrated with birds of an eastern origin, after accidentally joining the ‘wrong’ flock in winter.
For those ‘fair weather’ British Lapwings that spent the winter in France, Spain and Portugal, their journey back to their breeding grounds will be insignificant compared to that of the Swallows currently leaving their wintering grounds in South Africa.
It is not exactly known how Swallows time their departure, but changes in daylight, the weather and food supply are all thought to be significant factors. Certainly with the northern hemisphere on the cusp of entering spring, countries such as South Africa will now be heading towards their winter, resulting in mid-February seeing the start of a mass ‘hirundine’ exodus northwards.
How a bird weighing little more than 20g manages to navigate its way across 9,600km of incredibly varied terrain and sea still largely mystifies the scientific community, and in many ways is as close as we may ever see to a miracle. It’s now thought that migrating birds, such as Swallows, are employing a ‘magnetic compass’ to some extent, but this is certainly not the only cue they will use. Perhaps the position of the sun in the sky, or the pattern of polarised light on a cloudy day will also help, and they may also use landmarks, topographical features and even familiar smells when homing in on sites previously visited.
With the Swallows at last on their way, the Puffins will also finally be coming towards the end of their seven-month stint out at sea and, moult permitting, should be slowly turning their beaks towards their breeding grounds. Puffins are long-lived birds, with the oldest known bird re-caught on the Western Isles in 2012 just short of its 37th birthday. Being masters of longevity means that Puffins also have a slow adolescence, rarely reaching adult maturity until at least four or five years of age. This slow maturation means that juvenile birds will take a few seasons to develop the full characteristic adult appearance, and so young birds can easily be identified by their much smaller, less colourful bills with fewer grooves, and muted tones to their plumage. As these one- and two-year-olds will currently have virtually no chance of either attracting a mate or securing a burrow in the socially complex world of a Puffin colony, many of these ‘teenagers’ will simply steer clear of the colonies. Preferring to stay at sea, they will then be free to ‘look after number one’, biding their time until they feel ready and able to enter the cut-and-thrust world of a thriving puffinry.
Like the juvenile Puffins, Waxwings are in no hurry to leave their wintering grounds either, but for a very different reason. In common with the Bewick’s Swans preparing to depart for their Arctic Russian breeding grounds, the Waxwings won’t return to their northern Scandinavian summer territories while they are still snow- and ice-bound. With summer arriving much later in northern Norway, Sweden and Finland than in the UK, conditions may not even be suitable for nest building until at least early June. This means the Waxwings will still have plenty of time to track down the ever-diminishing supply of berries here before the migration instinct takes over.
Come the middle of February, a combination of data collated from satellite transmitters, geolocators and ringing recoveries all suggest that our British-breeding Cuckoos and Nightingales will both still be safely ensconced on their regular wintering territories. Even for these late departees, their primarily insectivorous diet means they should be in no immediate hurry to scramble back to a cold, wet and windy Britain. Staying where the feeding is good makes infinitely more sense, and they should be confident that when the time to leave does come, they will depart in the best possible condition.
Late February
Having spent just over the last six months as grumpy hermits, it’s now time for the Kingfishers to play centre stage in the mating game. Late February and early March are great times to watch these iridescent beauties put their early un-cooperative attitudes behind them, and turn over a new leaf by entering into their new relationship with a touch more gusto. With the slightly forced introductions now behind them, the Kingfishers will begin to cement their bonds for the oncoming breeding season by conducting noisy aerial flights as they chase one another up and down their territory. These high-speed games of pursuit can sometimes last for hours, as one minute they whizz past a few inches above the water, only to return a few seconds later well above the tree tops. It can also be tricky at this stage separating aggression from romance, and it is not uncommon to sometimes see three kingfishers pursuing each other, with an interloper hoping to gatecrash the party.
Despite being so brightly coloured, many novice birdwatchers often struggle to catch sight of a Kingfisher because of the sheer speed at which they move around their territory. But the key is to listen for their shrill, tinny whistle, often given in flight, which tends to both announce their arrival and prepare you for a fly-by. Unlike many other birds, a Kingfisher’s territory will be a linear one, often consisting of anywhere between 1km and 1.5km of river, stream or lake edge, and most of these courtship flights will tend to be centred around prospective nesting sites.
With the Kingfishers busily committing to one another, the male Lapwing in late February will be principally preoccupied with establishing a territory. Only when secured will he be in a position to woo a female, by demonstrating both the quality of his real estate and the calibre of his display within it. Nesting in open sites like farmland, pasture, marsh and moorland, Lapwings are on the one hand strongly territorial birds, but on the other, a species that often prefers to nest in loose association amongst its own kind. While group defence against dangerous predators like Foxes may make little real difference, an angry mob of Lapwings will be far more effective in driving away a marauding Carrion Crow from their eggs and chicks than that of a single pair nesting alone.
Lapwings have a complex series of breeding season behaviours, some of which are conducted in the air while others are confined to the ground. Territorial establishment starts with the males occupying definite positions, which will then proceed to form the core of their territory. These territories can vary in size, and Lapwing expert Michael Shrubb’s studies seem to suggest that in Britain they may vary between 0.3 and 0.9 hectares. When territories are being laid down, boundary disputes are common and tend to see the rival males facing one another while puffing out their breast feathers and drooping their wings a little. Following this face-off they will then turn to walk in parallel along an imaginary line, as they conduct a staring match on the move. Early on in the season these staring bouts can also become physical as they flutter into the air while trying to drive their competitor down with a few well-placed kicks.
The most important ways for Lapwings to declare ownership, however, are with the aerial ‘alternating flight’ display and distinctive ‘song flight’, which when seen must rank as one of the great spectacles of early spring. Most common at dawn, dusk and even at night-time, the ‘alternating flight’ consists of the male flying in a zig-zag course, while showing his black and white plumage to its full extent, as he works the boundaries of his territory. This flight is often accompanied by a distinct thrumming noise made by the wind whistling through his outermost primaries. The male may then mix up the ‘alternating flight’ with his ‘song flight’, which comprises a rise up, followed by a steep tumbling, twisting dive. This impressive aerobatic feat is always accompanied by his characteristic ‘pee-wip, wip, wip, pee-wip’ call – once heard and seen, never forgotten!
These aerial manoeuvres serve to pass on a
variety of messages to any other Lapwings looking on. Firstly, they advertise not just that he is in possession of a territory, but also the size and dimensions of that territory. Additionally, because his flights are so physically and technically demanding, he is demonstrating to any neighbouring males and unmated females watching from the sidelines that he is fit, agile and a force to be reckoned with.
While continuing to dazzle with their own display flights, and just a few weeks before the female will start to produce her clutch, the pair of Peregrines will be cementing their bond with a combination of courtship feeding and ritualised ledge displays at the nest site. Co-operative hunting will now fall away as the female insists that it is the male alone who must provide her with all her dietary needs in preparation for the rigours of egg laying and beyond. Initially, he may be a touch reluctant to feed her, but as he gets his act together he will fly in with prey to where she is perched, and then transfer the meal to his beak, before passing it to his hungry mate. He will also sometimes drop the prey on the ledge after landing and retreat to let her enjoy the meal, or simply drop the prey to where she is perched as he flies past.
