Why a flock of these smart-suited Scan­di­na­vians could be head­ing your way!

Bird Watching (UK) - - Contents -

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.

HAND­SOME THRUSH All thrushes are hand­some, of course, but par­tic­u­larly the colour­ful Field­fare

WIN­TER VIS­I­TOR Field­fares are clas­sic win­ter vis­i­tors, able to tough out a bit of snow, if we ever get any...

BERRY EATER These thrushes eat a lot of berries, but not of a great va­ri­ety of types, stud­ies have shown

MATCH­ING HEAD AND RUMP Field­fares have a dis­tinc­tive match­ing blue-grey head and rump

BOLD COLOURS Field­fares are the most strik­ing of Bri­tish thrushes, their colours set off against a tail of black

AWK­WARD FEED­ERS Although pri­mar­ily berry feed­ers, Field­fares have a rather un­gainly style, lack­ing great agility

HARSH WEATHER Field­fares par­tic­u­larly ap­pre­ci­ate fallen fruit such as ap­ples in the cold­est weather

FLOCK FEEDER Gen­er­ally, Field­fares are flock­ing birds, tol­er­ant of other Field­fares and Red­wings when feed­ing

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