Nightingales in November (10 page)

With summer arriving in Arctic Russia and northern Scandinavia much later than at the temperate latitudes of Britain, our two winter visitors are in no immediate hurry to leave our shores for their still frozen breeding grounds. Numbers of Bewick's Swans are still high in early February, and as winter draws to a close, those populations that have spent most of the winter feeding on arable crops may well be forced over to pastures as their first choice becomes far more depleted. Also faced with the local exhaustion of food supplies, Waxwings at this stage of the winter will have to range far and wide to get their berry fix.

Where they do manage to locate plentiful supplies of food, the Waxwing's technique often seems to involve little more than eating large volumes of fruit in one sitting. The record for ‘prodigious Waxwing eating' must go to a bird seen in Pembrokeshire during the winter of 1949/50. When watched for most of the day observers estimated one
individual bird to have eaten between 600 and 1,000 fruits of
Cotoneaster horizontalis.
Unlike many perching birds, Waxwings don't possess a crop in which to store these huge meals, but do have a section of the oesophagus that extends under the skin of the hind neck, which during intense feeding bursts fills in a similar way to a hamster's pouches. Suffice to say that the 90g of fruit estimated to have been eaten by this bird still amounted to twice its own body weight!

Faced with the cold conditions in the North Sea and North Atlantic it's a fair assumption that our British-breeding Puffins will currently be preoccupied with finding enough food to eat throughout the daylight hours, particularly with an energetically expensive moult to be completed. From time-depth recorders placed on Puffins by researchers on the Isle of May during the breeding season, it was found that birds feeding chicks averaged over 1,000 dives per day, spending close to eight hours under water! Despite not having to fly to and from the breeding colonies, as the sea temperatures will be lower and food more difficult to find at this time of year it's a fair assumption that certainly during the short days, the overwintering Puffins will have little time for loafing at the surface.

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.