Nightingales in November (42 page)

The mass feather replacement that is the annual moult won't just be restricted to Robins at this time, as Blue Tits, Lapwings and Nightingales will also be busily shedding and regrowing feathers in preparation for either a winter spent in Britain or a more benign climate elsewhere. As the adult Blue Tits slowly continue their moult, their young will also begin to replace the hastily grown juvenile feathers for a
set that will allow them to survive their first winter and last until their first breeding season. For these immature birds the most important feathers to replace will be those around the head and body, which will not just ensure better insulation but enable them to play a full and vigorous part in the mating game the following spring. This post-juvenile moult means that young Blue Tits will not actually replace their flight and tail feathers until completing a full annual moult following their first breeding season, resulting in them only becoming indistinguishable from fully adult Blue Tits at the grand old age of 17 months.

Also keen to retain the power of flight during their moult, the annual replacement of feathers will not prevent a large number of continental Lapwings from reaching Britain throughout July and August. Arriving first on the east coast, these Lapwings which will have summered on the continent will probably just slowly melt into the flocks of British-breeding Lapwings already roving the countryside. The origin of these Lapwings may vary from eastern European birds, which commonly undertake a post-breeding westerly or north-westerly movement to reach Britain, to those dispersing south-west from breeding grounds in Scandinavia.

By contrast, no such advance movement will be seen from those Nightingales that successfully bred in Britain earlier in the summer as their rapid moult will see them quietly feeding away as they attempt to take on sufficient fuel to power the quick growth of their new feathers before their flight to west Africa. Like the Blue Tits, the juvenile Nightingales will also at this stage be undergoing a partial moult of primarily their body feathers and some of the coverts
(the feathers covering the main flight feathers) but their primaries will not be replaced until this time next year.

By the middle of July, data collected by the BTO suggests that the male Cuckoos will have already made their choice as to the migratory route they will take into Africa, with the birds seemingly split between those Cuckoos preferring the Iberian route and those deciding to travel via Italy. Chris the Cuckoo is currently the only bird to have successfully carried a fully functioning transmitter for four years until his demise in the summer of 2015 and, interestingly, was a bird that always chose the Italian route down to Africa. It seems certain that Chris, and possibly many of the other Cuckoos too, tend to be site-faithful to a few tried and tested locations during their migratory route and undoubtedly for Chris the most important stopover in southern Europe was the huge Po Valley in northern Italy. Travelling over 600km from its source in the Cottian Alps to its mouth in the Adriatic Sea, the River Po is the longest in Italy and surrounded by an expansive, fertile flood plain, which has now largely been converted to agriculture. The delta on the Adriatic coast is considered particularly important for migratory birds with the Po Delta Regional Park designated as a World Heritage Site in 1999. Consisting of wetlands, forest, dunes and salt pans, this site must obviously be the perfect place for a British-breeding Cuckoo to spend time fattening up before traversing both the Mediterranean and the Sahara Desert in one enormous leap.

With their biological parents ready to exchange Europe for Africa, the young Cuckoos should still be feeding up in Britain prior to their own departure. After fledging there appears to be a period where the young Cuckoos will leave the location where they were reared to spread out in any direction. This seemingly random movement mostly tends
to occur over a short distance, and despite British juvenile Cuckoos having been recorded as far away as Denmark and Germany, this ‘wanderlust' shouldn't be confused with their proper migration to Africa, which will still not be conducted for a couple of months. In many ways the young Cuckoos' journey is even more remarkable than that of their errant parents, as they will not have been able to either learn the route from older, more experienced birds or orientate themselves with the help of familiar features in the countryside. The only conclusion to draw is that the young must follow some kind of genetically hard-wired satellite navigation system, which not only specifies both direction and distance but can also be re-calibrated for variable weather conditions or any obstacles encountered along the way. Irrespective of how this feat is achieved, their piloting skills across thousands of kilometres of utterly alien territory remains one of the great feats of the natural world!

Late July

After six weeks spent underground being waited on ‘wing and foot' by its parents, the young Puffling should by now be finally ready to leave the confines of the burrow to make its bid for freedom. Weighing in at around 35 to 40g when hatching, the Puffling will have reached between 250 and 350g by week five, before this final week sees the bird frequently losing a little weight. This ‘slimming' programme comes about as a result of a rapid increase in exercise from the constant flapping of its wings and also a decrease in the amount of food brought in by the parents. This crucial weight reduction will primarily ensure the young Puffin is not too obese to ‘lift off' at the defining moment it decides to exchange the land for the sea. Despite losing around 10% of its body weight during this time, the Puffling will still
have retained more than enough reserves to see it through those first few critical days out at sea while honing its foraging skills.

With so many avian predators keen to make a meal out of a naive young Puffling, the youngsters will only ever leave for the surrounding sea under the cover of darkness. Although the fledging of the youngsters across a large colony can often be spread over a few weeks, on a good night hundreds will often leave the colony within a few hours. Moving to the burrow entrance, the Puffling will often linger at the entrance to get its bearings before a last minute preen and a fluffing-up of its feathers then sees it take to the air for the first time. A good sense of direction is vital as the Puffling attempts the most important short flight it will ever make, often only staying airborne just long enough to splash down in the comparative safety of the water, no more than a few hundred metres from where it was reared. Having successfully navigated away from the puffinry and any chick-hunting gulls still patrolling the burrows on a late shift, the young Puffin will take to the sea just like a duck to water. Able to swim and dive instantly and keen to capitalise on such a confident start, it will then set about distancing itself from all the predators circling the colony to reach the safer waters further offshore. Such is the youngster's eagerness to leave its birthplace behind, by daybreak it could have already paddled several miles out to sea, perhaps even linking up with other recently fledged Pufflings or any adult birds loafing around at the surface in preparation for their post-breeding moult. The parents are thought to play no active part in encouraging the young from the burrows, to the extent that some adults may even briefly continue to bring back food to an empty burrow, seemingly unaware that their chick has already flown the coop. With their chicks having fledged there will then be little incentive for the adults to linger any longer than necessary, and a rapid desertion of the colony will quickly
ensue, leaving the puffinry pretty much devoid of life by the end of the month.

Able to feed themselves almost immediately upon leaving their burrows, the juvenile Puffins are certainly quicker learners than the Tawny Owls which, despite having clambered out of their nest as long ago as early May, will only now begin hunting their own food in earnest. Whether the young birds are pushed or jump towards self-sufficiency is unclear, but the motivation may well be a combination of the parents slowly withdrawing their ‘meals on wings' service as the youngsters themselves steadily take matters into their own hands. Either way, as the incessant begging gradually declines the young will probably only be tolerated for a couple more weeks in their parents' territory, before it's made perfectly clear that they'll need to take their chances elsewhere.