Read Nightingales in November Online
Authors: Mike Dilger
Having suspended feather replacement until their young were fully fledged, the juveniles' increasing independence should finally allow the adult Peregrines the peace and time to quietly finish their moult by the autumn. In many cases it will also be in the adults' interest to remain on their breeding territory all year round where possible, as any falcons âdeserting' a claim could find it occupied upon their return. Their attachment to sites will of course depend on the availability of food throughout the winter, and certainly for those pairs nesting in towns and cities, the presence of feral pigeons all year round may mean there is no need to leave at all.
With many urban sites also able to offer an abundance of roosting sites, it is not difficult to see why available Peregrine territories in some British towns and cities may be in short supply, if not already at saturation. The fact that fledging Peregrines may be finding it more difficult to find suitable territories was recently revealed by one of the first confirmed
cases of co-operative breeding in Britain. As shown on the BBC wildlife programme
Springwatch
, a young male raised in 2011 from a well-known site in the city of Bath was then filmed helping to raise his parents' 2012 brood. While a touch clumsy and haphazard due to his inexperience, he was nevertheless able to beg a share of the food from his parents while also enjoying their protective custody. Helping to rear his own kin might also mean that he could be in a prime position to inherit a top piece of Peregrine real estate should any tragedy befall his parents in the future.
As only a tiny minority of ringed Puffins have ever been recovered away from their traditional nesting sites, until recently very little was known about the travels of these mercurial seabirds after the breeding season. When not tied to their colonies Puffins are rarely seen from land, and so were assumed to disperse widely offshore. Additionally, as no large flocks ever seem to be spotted, it is believed they must also spread out at a low density, possibly in small, scattered groups. In recent years there has been a major advance in our knowledge of their movements through the use of geolocators. While having limitations as a technique, due to any birds with the logging devices attached needing to be re-caught and an inherent geolocation error of ±185km, the work of Mike Harris
et al.
studying the Puffins on the Isle of May has revealed they are indeed very mobile. The data-loggers recovered for this breeding site off Scotland's east coast have revealed that after initially remaining in the north-west North Sea, and reasonably close to where they bred, a movement then takes place. The research work revealed that three-quarters of the birds successfully followed then moved around north Scotland, to spend most of the rest of the year well out into the Atlantic. By comparison, recoveries of ringed birds from populations in western Britain seem to suggest that they
may disperse even more widely than those Puffins from the North Sea, with west coast birds moving through the Irish Sea and recorded anywhere from Greenland and Newfoundland to France and the Western Sahara. It has also been suggested that the movement of Puffins from eastern colonies to the Atlantic may be a relatively recent phenomenon, brought about by worsening conditions in their traditional North Sea wintering grounds. With sea temperatures rising in the North Sea, this may have lead to the Puffins' food being driven further north, which in turn will have lead to the birds themselves being forced to follow.
For those Cuckoos, such as Chris, that entered Africa via Italy, the end of August should find the majority of these birds fattening up in and around the Eastern Sudanian savanna in southern Chad. The location of this sub-Saharan stopover appears to differ, however, from those Cuckoos that took the Spanish/Portuguese route into Africa. According to the satellite telemetry data these Iberian birds seem to prefer feeding and resting up at this stage of their journey in northern Nigeria, at least 1,000km further west of their Italian cousins. The feeding area for the more westerly Cuckoos seems to fall into the Western Sudanian savanna, a habitat that, while heavily fragmented due to the large human population in Nigeria, is considered broadly similar to the savanna habitat currently being used by the British-Italian Cuckoos.
Over 4,500km away, back in Britain, the adult Cuckoos' progeny should still be gorging themselves on a variety of caterpillars and other invertebrates as they too prepare to depart. A few weeks after gaining independence from their weary host parents, there does appear to be an element of dispersal from where they hatched, as the young Cuckoos spread out in all directions. With a couple of records of
British-reared juveniles observed as far away as Denmark and Germany during this period, this movement is believed to be different from the proper migration, which observations seem to confirm does not occur until early September.
If the movement of Nightingale OAD is representative of the migration of many British Nightingales currently on their way to Africa, then the end of the month should find them in transit towards the Iberian Peninsula. The data from the geolocator of Nightingale OAD certainly indicate that the slow progress of this bird seems to be because it will have been feeding en route, and with little of the haste that proved such a prominent feature of other tagged Nightingales followed to the breeding grounds in spring. Having taken a detour around Paris in the middle of the month, the fourth
week of August saw OAD skirt past the western end of the Pyrenees, heading down to Madrid before then taking a right-hand turn towards its third European capital city in the space of just a couple of weeks â that of Lisbon in Portugal.
The believed migration route of Nightingale OAD between England and north Africa in the autumn of 2009.
In most years the fledging of their second brood will mark the end of the breeding season for many British Swallows. Finally freed from the constraints of chick-rearing means the adults may keep this second family together for a longer period than would have been the case for their first brood, with some kin possibly remaining together until at least the point when migration gets under way. Still not terribly competent flyers, initially the newly fledged young will need any help they can get as they come to terms with the very real dangers posed by domestic cats, Sparrowhawks and moving traffic. However, after a few days of flying lessons the young should have become sufficiently proficient to spread their wings further afield as they begin a process of familiarising themselves with both the general area and the local Swallow population. Gaining a knowledge of their immediate neighbourhood is not only believed to aid with successfully navigating their return the following spring, but also to help pinpoint any potential breeding sites or roosting spots in future seasons. Certainly for Scottish Swallows, however, these âfact-finding' trips will not last long, as the deteriorating weather and shorter days combine to push the birds further south. Travelling initially short distances, as they migrate by day and roost by night, it won't be long before the Scottish Swallows begin joining forces with their English and Welsh cousins as the entire summer population prepares for a mass autumn exodus.
While the last wave of insects emerge and migrant moths and butterflies take their final fix of nectar before the frosts set in, the first official month of autumn will bring a feeling of change as the slow descent to winter begins in earnest. Bursting forth with nectar and foliage in spring and summer, our trees and shrubs will suddenly become laden with seductive seeds and fleshy fruits. This annual bonanza will have come just at the right time for dormice preparing for hibernation, squirrels stashing for winter and our resident birds looking to lay down fat for the lean times ahead, but too late for the vast majority of our summer visitors, which should by now be busily crossing continents. It's not all one-way traffic though as the relatively mild climate and abundant food offered here will draw a whole new cast of characters keen to spend the winter in Britain.
Early September