Fieldfare
Why a flock of these smart-suited Scandinavians could be heading your way!
NOW IS THE time of year when, opening your curtains in the morning, you might be surprised to see a flock of Fieldfares in your garden. Yesterday evening there might have been nothing on the lawn but damp fallen leaves, but this morning the grass is dotted with these colourful, sharp-suited Scandinavians.
They are an overnight arrival, quite unexpected, at a time of year when you don’t tend to witness sudden movements of birds, unless there has been severe frost or deep snowfall. These Fieldfares, though, just appear from nowhere. Tomorrow, or the day after, they might well disappear as abruptly as they came. Fieldfares can be difficult species to pin down. Think about your winter birding for a moment; in your experience, could you guarantee to see a Fieldfare at any location nearby, every time, between October and March? There are probably some places where this is the case, but you will probably note as many absences as appearances. Where I live, on the south coast, there are many places where it is a cast-iron certainty that you’ll see wintering Brent Geese, or Common Gulls, but you cannot be sure of Fieldfares. These winterers are ‘now you see me, now you don’t’ sorts of birds, teasing us. And yet, in terms of their migration, Fieldfares are well understood. They are studied thoroughly enough for us to know, for example, that Norwegian Fieldfares favour north-west England, Scotland and Ireland, while Swedish and Finnish Fieldfares are commonest in the south-east. And their mid-winter and late winter movements make sense, even if the birds themselves are full of surprises. In summary, you might say that they are predictably unpredictable. To understand properly what is going on now, it makes sense to go back to the autumn and take a closer look at Fieldfare migration. As most birders are aware, Fieldfares, along with their close allies Redwings, are non-breeding visitors to Britain, save for a very small population that remains in summer. Most of our birds come from Fennoscandia, but the species breeds widely in Central Europe and across much of Eurasia. Birders are often surprised to see Fieldfares on summer lawns in Germany and Poland. Another surprising statistic is that some individuals from Russia winter in south-east France and northern Italy, making an east to west migration of over 6,000km, one of the longest known in that direction for any bird. To be honest, seeing Fieldfares fly in their shallow, undisciplined, somewhat feeble looking style, one wonders how they make it across the North Sea, let alone any further! Anyway, our Fieldfares originate in Norway, Sweden and Finland and, in contrast to many an autumn migrant, they are in no hurry to leave
their breeding areas in the autumn. While your average Willow Warbler has left the vicinity of its nest before the end of July, most Fieldfares are still present within 50km of their breeding areas at the end of September. Only in October do they begin to fly over to us, often arriving in large numbers overnight during easterly winds. If there is a good crop of Rowan berries, many will be tempted to stay behind on the continent even longer. First-year birds may not make landfall in Britain until November or, perhaps, even December. This means that, throughout the last three months of the year, Fieldfares may still be arriving in Britain from overseas. So, not only do they migrate late as a species, but many individuals are still moving considerable distances in mid-winter, and this at least partly explains why these thrushes have a reputation for simply turning up unannounced. When they arrive here, Fieldfares make a bee-line for berry-bearing bushes, not only Rowan but also, in particular, haws. In contrast to Redwings, which easily take to the woodland floor, Fieldfares are exclusively open-country birds when foraging, preferring fields with lots of hedges. They do, however, roost in woodland and thick scrub. Although berries are their dietary mainstay, they will readily eat invertebrates from the soil at any time of year, particularly earthworms. They freely mix with Redwings on old pasture and, according to an intriguing recent study, they seem to gain information from the smaller birds about the location of food when feeding at such sites. The Redwings, meanwhile, don’t seem to gain from being in mixed flocks with the Fieldfares and, who knows, may be peeved by the presence of their relatives. Oddly, despite being larger than Blackbirds and breeding further north, Fieldfares are evidently not as good at surviving winter adversity as the more familiar bird. A study near Oxford found that there they only utilise four types of berries to any great extent (haws, rose hips, hollies and Ivy; Rowan was not abundant in the study site) and only 12 wild fruits in all in the winter months, whereas the local Blackbirds were able to feed on more than 30 different wild fruits.
On the whole, these thrushes are peaceable and sociable, but, under difficult conditions, some individuals go rogue
Fieldfares feed rather awkwardly on berries, perhaps without the agility to pursue different sources of fruit. At any rate, they seem to be limited in their berry-eating ability. What with an apparent dependence on Redwing know-how to feed well on old pastureland, the Fieldfare comes across as a somewhat clueless species at times! What Fieldfares can do, though, is move about, becoming the wayfarers of the fields. Once they have settled in a region after the middle of December, they then seldom move far, taking short, nomadic excursions around the immediate area. Ringing studies show that any movement in the new year of greater than 20km is quite unusual, until the birds begin their migration north in the spring. However, that still gives scope for a great deal of travelling around. They go, of course, in search of food. Having begun each nomadic movement in the morning, they settle when they have found something and remain until it is exhausted. And these small-scale movements inevitably take them away from their core habitat, and into those strange little parcels of land known as gardens. These movements will be the greater if the weather is harsh. By the early spring, the autumn production of easily obtained berries begins to run out, and this means that the birds are compelled to widen their search for sustenance. In the wild, when it is cold and the ground is frozen, Fieldfares turn to searching for rose hips around February and supplement these with Ivy. However, they appreciate apples at this time of the year. In harsh winter conditions, thrown-out apples are very likely to attract these birds. If you do provide them, you might observe an unusual piece of Fieldfare behaviour. On the whole, these thrushes are peaceable and sociable, but, under difficult conditions, some individuals go rogue, so to speak, and try to save all the berries or apples for themselves. Such individuals send most of the day driving other birds away from their precious fruit stores, rather than actually eating the food. Only about one in a hundred do this. Most of the population are off as soon as the berries are finished, or the ground thaws. The birds move on, not to be pinned down. And then they will appear, overnight, somewhere else.