Read Nightingales in November Online
Authors: Mike Dilger
Fledging around the middle of August, the warm temperatures mean there should still be more than enough invertebrate food available for the Swallows' second broods to catch as they come to terms with the joint tasks of both defying gravity and eating on the wing. From extensive data collected by bird ringers, it does seems that these later broods tend to experience much lower survival rates compared to the first broods fledging earlier in the year. Based on the number of birds returning the following spring, a number of theories have been put forward as to why Swallows that fledge later might have drawn the âshort
straw'. First, the difference in diet between the first and second broods seems to be an important factor. The food available to Swallows of course will vary throughout the year, with an increase in aphids and a decrease in large flies observed as the summer proceeds. As the high nutritional value of large flies makes them far more profitable to hunt, their decline in abundance throughout the summer may mean that any fledged Swallow will have to work harder for the same nutritional return. This is compounded by the fact that in mid-August, the days, and available light for foraging, will be much shorter than in late June. Also for those second and even third clutches reared in the exact same nest-cup as an earlier brood, an increase in the number of blood-sucking mites could also affect the general level of fitness of the chicks. Any small and subtle difference in the juveniles' health could mean the difference between life and death as the Swallows push their bodies to the limit during the physically stressful and hugely demanding autumn migration.
By the middle of August, the power of flight should finally be returning to the adult Bewick's Swans as they continue replacing their flight feathers up on their Arctic Russian breeding grounds. For those parents with cygnets, this should enable them to once again step up their level of protection against any marauding predators. Now over a month old, the surviving cygnets should be swiftly replacing their off-white down for their first full set of feathers. Sporting a dusky grey plumage and a flesh-coloured bill, the young are easily differentiated from the snow-white plumage and characteristic yellow and black bills of their parents for some considerable time. In fact the full adult plumage will not appear until at least their second winter back in Britain, and with a couple of additional years passing before they will
even contemplate a first breeding attempt, the swans could easily be at least six or seven years old before they are sufficiently experienced to see their own young successfully through to fledging.
By now freely moving around the taiga forests, the family parties of Waxwings are now believed to start aggregating into larger flocks as they go about their regular routine of feeding and roosting. This flocking not only serves as protection against predators, but is also thought to operate as an informal information exchange, with hungry birds following those well-fed individuals which have patently located good feeding grounds out of the night roost. Not content with just the company of their own species, the Waxwings may also associate at this time with other species which have bred in the forests of northern Europe, such as the Fieldfare. This noisy, gregarious and garrulous member of the thrush family has always remained an incredibly rare breeding species in Britain, with no more than a handful of confirmed records at a few remote sites in Scotland and northern England. However, each winter up to a million birds will cross the North Sea to help themselves to our berry crop, making them a far more abundant and regular visitor to Britain than the erratic Waxwings.
Becoming ever more adept at feeding themselves, the young Peregrines will be continuing to venture further afield in late summer, safe in the knowledge that the âcomfort blanket' of their parents' territory will still be there if necessary. While some may attempt to breed the following spring, the majority of juveniles are not thought to give it serious consideration until at least their second year and so will join
a non-breeding population, whose numbers, distribution and movements are still little known. From studies of the movements of young Peregrines compiled by the BTO, the median distance travelled by over 500 ringed birds was just 45km, with only around a fifth travelling more than 100km from their birthplace. Despite ringing records suggesting that juveniles do not travel too far, this post-breeding dispersal could account for the old falconer's terms of âpassage hawk' for any falcon in immature plumage observed in non-breeding areas. The movement of young British Peregrines over relatively short distances contrasts with other populations of Peregrines found, for example, in North America and across northern Europe and Russia, which are highly migratory, giving clarity to the derivation of the Peregrine's scientific name
Falco peregrinus
, which translates as âwandering falcon'. These young birds will ultimately hope to fill the gaps caused by mortality in the surrounding breeding populations, and if lucky, skilled and tenacious enough, may even go on to establish new breeding sites themselves.
Also leaving behind all they've ever known as they attempt to either carve out their own territory, or at the very least stay out of trouble, the young Tawny Owls will finally leave their parents behind. Left alone to finish their moult in peace, it is doubtful that the parents will ever venture far from their established territory, as even when prey is thin on the ground, the pair would rather stick than twist. This incredible site fidelity may be one of the reasons why no ringed Tawny Owl has ever been recovered abroad or even foreign-ringed individuals found here, suggesting that the British population of Tawnies is a particularly isolated one. This may indicate that at some point the British Tawny Owl could even become a candidate for
being a separate subspecies â with
britannicus
surely a suitable epithet!
Chased and harried by their parents, the local Kingfishers should once again briefly turn their waterfront into a blur of blue and orange as the second brood are chased out by their parents in a none too subtle fashion. The evicted juveniles, however, will have a few options â they can either find their own uninhabited stretch of river or lake, move to the coast where there is less competition or stay and fight for a stretch of river already occupied. Attractive territories, while being rich pickings, are often fiercely defended, and very few end up being wrestled away from older and more experienced birds, but it is not unprecedented. Wildlife cameraman Charlie Hamilton James, for example, observed a very strong-willed subadult female, which he thought came from the year's first brood, that managed the feat of ousting the established resident pair holding territory adjacent to his house in the West Country. Once the young have dispersed, the river may suddenly and temporarily fall very quiet as the adults concentrate on completing their moult in peace, only too aware they will soon have to go back into battle to re-secure their own winter territories.
While fish in the rivers should still be plentiful for any homeless juvenile and moulting adult Kingfishers, this time of year can often present real difficulties for those species which feed principally on soil invertebrates. In a hot, dry summer the soil can quickly turn hard and baked, making soil conditions far more difficult for birds such as Lapwings to forage for prey. Additionally, with many arable fields covered by wheat, barley, oats, rye and rape in summer, the soil also becomes more
difficult to access until the crop is harvested. Struggling to find enough food in farmland, feeding flocks during these summer droughts may instead be forced to feed in grassland or wetland habitats, with the result that normally peripheral habitats like reservoirs, gravel pits and sewage farms can often see an influx of hungry Lapwings at this time of year.