The Great Fall of Migrants - A Special Report

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THE GREAT F A L L OF MIGRANTS—A SPECIAL REPORT by H . E . AXELL a n d D . J . PEARSON

THE largest landfall of migrant birds ever recorded in this country occurred along the northern half of the Suffolk coast in the afternoon of 3rd September, 1965. It was remarkable not only for quantity but also because so great a variety of birds, seventy-eight species, was involved. The bulk were night-migrant passerines which are usual at that time of year but numbers of ducks, waders, terns, and finches also occurred. By far the most concentrated arrivals were seen between Sizewell and Hopton, with very few indeed to the south of this twenty-four mile coastline. Much less spectacular numbers arrived in Norfolk and representative species were seen on parts of eastern Britain as far north as Shetland. The movement was part of the peak departure of some millions of birds which had begun their migration from north-west Europe in fine, anticyclonic weather in the previous night and had become halted and concentrated on the north side of a depression moving north-west from Italy to the southern North Sea. Having lost their orientation under thick overcast and heavy rain, a large proportion of the massed migrants was moved towards Britain in the easterly airflow. A similar deployment of weather systems occurred on lst/2nd September, 1956, when the last fall of any size of disoriented migrants was seen on the Suffolk coast. T i m e s (BST) and Densities of Arrival The low pressure to the south-east had brought a dry overcast on a light north-north-east wind during the latter half of the night of 2nd/3rd September and those conditions had deflected only a few migrants to the Suffolk coast by early morning. At first light on 3rd, in the Minsmere sluice area there were ten wheatears*, smaller numbers of other chats, pied flycatchers and warblers and no noteworthy arrival was reported in the early morning from other parts of the coast that were later to be affected by the great rush. The approaching depression brought a thunderstorm at 7.30 a.m. and at 1.15 p.m. with the wind quickly freshening from the southeast and rain now heavy and continuous, the first of the avalanche of birds arrived in the Minsmere area. As the depression moved steadily northwards up the southern North Sea, so the coast began to experience the on-shore wind and the birds that came with it, the northernmost part of the Suffolk coast being affected a little more than an hour later than the onset of the rush at Minsmere. Two nights later, 5th/6th, the northward moving depression brought a change of wind and a record concentration of birds to Heligoland Light. The Netherlands coast also experienced a heavy landfall. The arrival of birds in the afternoon of 3rd was well covered by observers : • F o r scientific names, see Systematic List.


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Minsmere. The sudden appearance of large numbers, at 1.15 p.m., was a few minutes after the wind had freshened from the south-east. The large variety of species involved was immediately apparent but most obvious were the small passerines being blown in over the dunes, in very heavy rain, and soon Coming to ground. These, especially whinchats, redstarts, robins, garden warblers, spotted and pied flycatchers and willow warblers began to congregate in the bushes for shelter while wheatears kept to the open grass or flew a little further inland to perch on the tops of tall trees. As others, which had been Aying higher, dropped down, and ducks, black terns and sea terns, waders, swifts, and finches, appeared overhead in the sheets of rain, it was evident that some tens of thousands of birds were arriving. Observation over c. 150 acres of marsh and dunes was maintained until dusk when chats, warblers, and flycatchers were still arriving in the bushes at the coast ; few were now Coming in from the sea and many were seeking food in suitable habitats after the heavy rain began to ease and cease at 7 p.m. when the wind had then backed to north-west force 3. Counts were made at different times of certain species in selected areas and amongst the fifty-two species which had arrived over only a three-quarters of a mile front of the R.S.P.B, reserve's coastline, the most numerous of the small passerines were: wheatear 4,000, whinchat 750, redstart 7,000, garden warbler 2,000, willow warbler 500, pied flycatcher 1,500. Waders included golden plover 250, whimbrel 150, wood sandpiper 30, greenshank 60, little stint 20, and Curlew sandpiper 30. Of the rarer birds, dottereis, Temminck's stints, wrynecks, bluethroats, icterine warblers, tawny pipits, red-backed shrikes, and ortolan buntings, more were discovered next day when there was less confusion of species in other than typical habitat (see Table I and Systematic List). Observations over a wider area on the following day, 4th, indicated that, especially in the case of the chats and flycatchers, about twice the number of small passerines than had been counted and estimated in the one small sector on 3rd had in fact arrived on the reserve as a whole or had become concentrated in favourable habitats after arrival in areas adjacent to that covered during the actual fall. Counting on the 4th was impossible in the wellwooded areas of the reserve but multiplying up densities in some areas showed that, very approximately, some 10,000 wheatears, 15,000 redstarts, and 5,000 pied flycatchers, amongst thousands of other small birds, were present over 1,500 acres (HEA, RGHC, EH, PJM). Walberswick. Large numbers of birds were seen Coming in off the sea but details were not recorded on 3rd. However, between 6 and 8 a.m. on 4th, DJP and GLC made estimates of densities in an area from two miles of coastline south of Walberswick to three to four miles inland. The greatest density of passerines was just inland of the shore, rapidly decreasing west-


252 Transactions of the Suffolk Naturalists', Vol. 13, Part 4 wards and in this area there were at least 8,000 wheatears, 15,000 redstarts, 3,000 garden warblers, 1,000 willow warblers, 4,000 pied flycatchers and 1,500 tree pipits. Of the waders, many whimbrels had been heard on 3rd ; on the morning of 4th in the Walberswick area there were, new, 35 ringed plovers, 40 greenshanks, 10 little stints, 350 ruffs, and 400 dunlins as well as a sprinkling of common, green and wood sandpipes, Temminck's stints, curlew sandpipers, and a Kentish plover (RGB, GLC, DJP). Southwold. The arrival was seen to occur mostly between 2 and 2.30 p.m. with some birds still arriving up to 6 p.m. The predominence of species was about the same as had occurred to the south, with estimates, on the morning of 4th, of over 1,000 redstarts, several hundred wheatears. more than a hundred each of whinchats, pied and spotted flycatchers and small numbers of robins, warblers, and tree pipits. At least ten wrynecks, 2 bluethroats, and 12 black terns were seen (BAC). Waders heard included many whimbrels, greenshanks, spotted redshanks, green, wood and common sandpipers, and ruffs (GBGB, BAC). Covehithe. In the afternoon of 3rd, of a hundred small passerines per acre in a garden near the shore, most were redstarts (DR). Benacre Pits. Exceptional to the experience in other areas, the most common passerine in the afternoon of 3rd was pied flycatcher, half of the birds trapped by AGH being this species. Redstarts, some thousands seen, were less numerous and over 1,000 wheatears, hundreds of whinchats, garden warblers, and willow warblers, with small numbers of robins, whitethroats, spotted flycatchers, and tree pipits arrived along a few hundred yards of coast. Most of the birds came in between 2.20 and 2.50 p.m. with wheatears and redstarts, especially, arriving from just above the waves and many landing, nearly exhausted, on the beach. Only a small arrival was thought to have occurred after 3 p.m. Many hundreds of waders also occurred along the coast, principally grey and golden plovers, whimbrels, greenshanks, and dunlins (AGH). Lowestoft. At 2.16 p.m. on 3rd, a huge cloud of small birds appeared moving southwards over the town and beaches, some of the birds dropping down from this mass as it passed. What may have been the same great flock was observed at Corton and Hopton (per HEJ) and was seen to disappear south over Pakefield. It was considered by HEJ, who was on the front of Pakefield/ Lowestoft for the rest of the day, that after this landfall, which lasted for only a few minutes, little more arrival took place that day. As at Minsmere, this landfall occurred in heavy rain with a sudden change of wind to south-east.


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M r . F. Muddeman, describing the arrival on to Kensington Gardens, said that as he stood on the bowling green he noticed an intensely black cloud of birds overhead and the lower part of it suddenly broke away and descended where he stood, redstarts actually alighting upon his shoulders and arms. T h e groundsman of the Denes Oval had an exactly similar experience, seeing birds drop out of a great flock and having redstarts alight upon him. As well as thousands of small passerines, many waders arrived on the front of the town, including oystercatcher, curlew, green and common sandpiper, redshank, purple sandpiper ( 6 + ) , d u n l i n ; ducks, including teal, a great skua and several little gulls were also seen i n the arrival. O n the 4th, E W C J and H E J , inspected the arrival f r o m early m o r n i n g and BB and RB made estimates separately. Every patch of cover f r o m N o r t h Lowestoft to Pakefield contained small passerines and chats were everywhere common on open ground, to a necessarily roughly-estimated total of at least 30,000. Redstarts, several thousand, were the most numerous w i t h thousands also of wheatears and pied flycatchers. Whinchats were less numerous and hundreds each of garden warblers, w i l l o w warblers, whitethroats, and spotted flycatchers were seen, also c. 100 each of tree pipits and lesser whitethroats. A few wrynecks, ring ouzels, bluethroats, wagtails were also seen on 4th but more wrynecks (24) were located next day i n the Lowestoft Denes area (BB, RB, RC, FC, E W C J , HEJ). T h e d r i f t migration evidently thinned out very considerably to the north. A l o n g the three miles between W i n t e r t o n Gap and Horsey Gap, i n N o r f o l k , observations made by G . R. South early on 4th showed that only 1,000-1,500 redstarts were present i n this large area, w i t h several hundred wheatears, 500-700 pied flycatchers, good numbers of w i l l o w warblers and fewer whinchats, garden warblers, whitethroats and lesser whitethroats. O n the 3rd, the main landfall of drifted migrants is thus seen to have occurred on the Suffolk coast down to the dunes of Minsmere Level. Immediately south of this area there were unusual numbers of wheatears, whinchats, and redstarts near Sizewell power Station at early m o r n i n g of 4th but beyond this the arrival on 3rd was negligible. There was apparently no significant arrival at Aldeburgh on 3rd but by 7 a.m. on 4th E F C found 27 wheatears, 3 or 4 each of whinchats, redstarts, pied and spotted flycatchers, and willow warblers, and only one garden warbler, i n an area of four acres. A t Havergate, however, RJP reported many chats and pied flycatchers, some wrynecks and an influx of waders on 3rd but at Shingle Street, nearby, i n the early m o r n i n g of 4th, P R C and G E D found only 30 or 40 wheatears, 5 to 10 whinchats " and little eise " along a mile of the coast. B E reported no sign of any passerine migration at Boyton on 4th and there was a nil report by GJJ and F J F at Felixstowe.


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Relative abundance of the most numerous passerines Along the twenty-four miles of coast between Sizewell and Hopton it would appear, f r o m the counts and estimates made at various points, that more than half a million small passerines made a landfall in the afternoon of 3rd September. Redstarts easily predominated, their numbers all along the coastal area being in the neigbourhood of 250,000. Wheatears, some 100,000 were next in abundnace and were also generally distributed forming a high proportion of the fall at its southern limit. Pied flycatchers, numbering tens of thousands, were the next most numerous species in all areas and at one point of Observation, Benacre Pits, outnumbered any others at the time of arrival. Garden Warbiers were particularly numerous only in the southern half of the area affected by the great fall and spotted flycatchers appear to have arrived at separated points, as at Lowestoft, Southwold, and Minsmere, almost none occurring at Walberswick. Most of the 2,000 tree pipits occurred in the southern area, being more concentrated at Walberswick and somewhat fewer at Minsmere.

Further arrival At early morning of 4th, the coastal areas still held vast numbers of small birds and thousands of migrants were in areas inland. It is probable that the quantity which actually had arrived in the previous afternoon was greater than had been Seen in the poor visibility during the time of the landfall. T h a t the initial arrival had been augmented by any large further immigration seemed improbable because of the weather during the night of 3rd/4th when the light north-west wind backed south-west and the sky remained overcast—conditions which do not bring any numbers of small land birds in from the North Sea. During the first daylight hours of 4th, a very few passerines were observed to come in and these, still having been over the sea at nightfall on 3rd, would have remained disoriented by the absence of stars and would have been able to make a landfall when day brought the coast within sight. T h a t many were less fortunate and feil into the sea from complete exhaustion or killed themselves against lightships was evidenced from the n u m b e r of bodies later found on the tide-line.

Movement of passerines inland from the beach-head T h e very tired condition of a large proportion of the small birds was commented upon by all observers at the coast in the afternoon of 3rd. Apart from movement into the shelter of bushes and other cover during the heavy rain and selection of feeding habitat suitable to the various species when the weather improved, most of the small passerines remained in their area of arrival for the rest of the day. Birds which had landed on bare ground on t h e coast moved to the nearest suitable roosting sites at dusk. Noticeable


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exceptions, however, were wheatears w h i c h seemed i n much better condition and move about freely after their landfall. By 3.30 p.m. on 3rd, some were one and a half miles inland f r o m Benacre ; many, w i t h a few redstarts and pied flycatchers, were at Westleton, Blythburgh, and H i n t o n i n the evening and wheatears were Aying across the Westleton-Dunwich road between 6.30 and 7.00 p.m. D ü r i n g 4th, many thousand of chats and flycatchers were seeking food at least five miles inland f r o m the shore f r o m M i n s mere northwards to the B l y t h reaching the A.12 main road at Saxmundham, Y o x f o r d and Darsham, and as far inland as Haiesworth and Heveningham. Only comparatively few were further inland, odd redstarts being seen as far west as Härtest and Redgrave and also at M o n e w d e n and Kettleburgh ( W H P ) . A t Leiston and Snape, only wheatears were numerous. A t Benacre, pied flycatchers were found to have moved inland more quickly and more completely than other small species ; in the northern sector (Lowestoft area), pied flycatchers also spread inland more quickly o n the day after their arival. Other species were numerous up to three miles f r o m the coast f r o m Oulton Broad to the Blyth. O n the second day after their arrival, 5th, wheatears, redstarts, whinchats, and pied flycatchers were extraordinarily numerous up to four miles f r o m the affected coastal strip and were present in uncommon numbers several miles further inland f r o m Minsmere and Walberswick and to the south and south-west. Overnight, the sky has been mainly clear w i t h a light w i n d backing f r o m west to south and f r o m the Minsmere area, the only small passerine to have moved away almost completely was garden warbler. Except for the departure of this one numerous species, it could have been supposed that a complex of low-pressure systems around Britain might have inhibited the onward migration of the bulk of the other species ; the good weather was, in fact, mainly local. Indeed, it is possible that the garden warblers, most of w h i c h had landed i n one small sector of the landfall area, had had a less rigorous migration than the other species and had sufficiently restored their resources to enable them to move on after one night of rest and one f ü l l day of finding food. O n 5th September, whilst so many thousands had reduced the congestion by spreading inland to find food, only slight decreases were apparent at Lowestoft, Southwold, Minsmere and other areas w i t h good feeding habitats. Considerably fewer birds were present on Benacre Denes and a great decrease had occurred i n the open shore and heathland areas around Walberswick, though gardens, hedges, and copses still held numerous redstarts, warblers, and flycatchers. I n l a n d generally, and for a further distance than


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on the previous day, there were still as many chats and flycatchers on 5th as there had been on 4th. Apparently fewer whitethroats and willow warblers were still present but these may have been less conscpicuous because of their relatively lesser abundance. A wryneck was seen at Heveningham on 5th, with another found dead at Weston the same day. Twelve pied flycatchers were reported at Heveningham on 4th and one well inland at Hoxne next day.

Departure of passerines The main departure occurred overnight on 5th/6th. At Minsmere, where several observers were in the field each day throughout the period, wheatears were estimated to be down to a quarter on 6th, whinchats to one fifth but redstarts to only one third. Spotted flycatchers were only slightly reduced but pied flycatchers were down to one third. Robins and whitethroats were greatly reduced in number and tree pipits had largely disappeared, as they had done at Walberswick. Everywhere along the " invasion coast " a large general decrease was noticeable on 6th but the number remaining was still extraordinary. T h e 7th saw a still further reduction, particularly of redstarts and the departure of the remainder of the drifted migrants occurred progressively until 12th/13th after which night an approximately normal Situation was restored. Some southward movement over short distances had been observed. On the evening of 4th, some hundreds of wheatears and fewer whinchats appeared to be moving south near the shore and a similar general drift of these and other small species was apparent on 5th, more noticeably along Lowestoft Denes. Over 200 tree pipits and 40 flava wagtails were seen Aying south along the shore at Walberswick early on 5th. More flava wagtails were moving slowly south, pausing to feed, along the dunes from Minsmere to Sizewell next day. Spotted flycatchers, which had been few ?.t Walberswick on 4th, increased there on 5th and 6th. From 5th, species began to appear in areas to the south of those experiencing the original fall, e.g., on Sutton Heath three wrynecks, a few wheatears, redstarts, whitethroats, and pied flycatchers and tree pipits appeared where none had been seen on 4th; at Aldeburgh, more migrants, apart from wheatears, were present on 5th than on 4th ; Snape experienced unusual numbers of pied flycatchers, redstarts, and whinchats on 6th when only wheatears had been numerous on 4th ; at Bawdsey, redstarts and willow warblers, which had not been seen on 4th, appeared in small but increasing numbers up to 7th and a wryneck was seen on 6th and two next day. No drift migrants were observed by BE at Tunstall and Sudbourne on 4th, whereas D W saw good numbers of wheatears and redstarts in that area between 6th and 8th. At Shotley, increased numbers of wheatears appeared during the week after the 3rd


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Departure of waders Soon after their arrival on 3rd, many of the smaller waders had begun to search for food in unlikely places such as rain puddles in gravel pits, on roads and lawns. But by 4th, most of them had found more typical habitats and there were excellent mixed concentrations, including several purple sandpipers, at the north end of Lowestoft and Over 100 ruffs and several wood sandpipers on the Town Marshes at Southwold. The Blyth held, amongst many other waders, 120 ruffs and 200 golden plovers ; there were good numbers and variety at Walberswick where most of the birds were seen to depart southwards later in the day. At Minsmere, where some 2,000 waders of 19 species had arrived on 3rd, all the larger plover species, the curlews, whimbrels, bartailed godwits, common sandpipers, and redshanks had gone by 4th and numbers of other species were lower but little stints had increased to 25, ruffs to 150 and three dottereis were new. No movement of waders was observed by EFC at Aldeburgh but at Havergate on 4th there were many, including 40 ruffs. Some green sandpipers appeared at Snape on 4th and at Shingle Street on the same day there were 40 common sandpipers, some green sandpipers, 30 ruffs and a few greenshanks. Details of departure dates were not available from the most favoured feeding habitats except from Minsmere where perhaps the Situation after the arrival would have been typical of the rest of the area. After the big reduction found on 4th, numbers at Minsmere on 5th were about the same and on 6th only the knots had entirely gone. Thereafter there was a general daily diminution until 13th when the numbers and variety present were average for a normal year ; exceptionally, however, up to 20 little stints remained until 6th October. In broad terms, the length of stay and eventual departure of the drifted waders corresponded to that of the small passerines. Departure of other non-passerines Exceptional numbers of mallard and teal were not seen after the initial movements during the rush on 3rd, nor were the common, little, and Sandwich terns which had arrived at Minsmere. Black terns, however, stayed longer than any other species involved in the arrival of 3rd ; at Minsmere where by far the biggest flock, 150, had arrived, numbers feeding over the meres were down to 20 to 30 by 5th and c. 20 were present until 19th, c. 15 until 23rd and the last, four, were seen feeding over the same waters on 27th. Arctic skuas and great skuas which had occurred at Lowestoft on 3rd and Walberswick on 4th were seen again at those places on 5th. Two Ospreys were in the Minsmere-Westleton area early on 4th, one occurring later at Havergate and the remaining


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Minsmere bird moving off to the south next day. The large flock of swifts at Minsmere on 3rd was Seen only briefly at the beginning of the main arrival and a smaller group occurred at Southwold at about the same time ; the only later occurrence of a flock during the period was of one at Walberswick on 4th. Systematic list of species involved Mallard (Anas platyrhynchos). On 3rd September, many moved south at Lowestoft and c. 150 came in from the sea during the initial rush at Minsmere. Teal (Anas crecca). Incidence was about as mallard. 200 on the shore at Walberswick early on 3rd were before the main arrival. Osprey (Pandion haliaetus). Two at Minsmere and Westleton early (HEA, RGHC et al) and one later at Havergate (RJP) on 4th. One at Minsmere on 5th. Kestrel (Falco tinnunculus). Two at the shore at Minsmere on 3rd. Oystercatcher (Haematopus ostralegus). Fourteen at Minsmere and some at Lowestoft on 3rd. Lapwing (Vanellus vanellus). 110 came with the rush at Minsmere on 3rd. 400 on the Blyth on 9th. Ringed plover (Charadrius hiaticula). Local populations rose at Minsmere by twenty on 3rd and until 5th and by thirty-five at Walberswick on 4th. Kentish plover (Charadrius alexandrinus). One at Walberswick on 4th (GRB). Grey plover (C. squatarola). On 3rd : many south at Benacre ; sixty landed at Minsmere. Golden plover (C. apricarius). On 3rd : many south at Benacre ; 250 at Minsmere ; c. 200 present in the Blyth area on 9th. Dotterel (C. morinellus). Two on the shore and one put up from the dunes at Minsmere on 4th (HEA). One north of Sizewell on 6th (CC, DM). Turnstone (Arenia interpres). Fifty with the main rush at Minsmere on 3rd. Small parties at Lowestoft on 3rd and 4th. Curlew (Numenius arquata). Fifty at Minsmere and several at Lowestoft on 3rd. Whimbrel (N. phaeopus). On 3rd : many heard moving south at Benacre and Walberswick ; many at Southwold. 150 landed at Minsmere. Black-tailed godwit (Limosa limosa). One feeding on a flooded tennis court at Lowestoft on 3rd. One at Walberswick on 4th. One at Herringfleet on 5th.


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Twenty landed at Minsmere

Green sandpiper (Tringa ochropus). On 3rd : small parties on flooded lawns, etc., at Lowestoft and Southwold ; on 4th : a few still present at Lowestoft ; four on a flooded gravel pit at Westleton ; four at Walberswick ; several at Snape and Shingle Street. Twenty in the Blyth area, 5th to 1 Ith. Wood sandpiper ( T . glareola). Only record on 3rd was of thirty at Minsmere (down to twenty on 4th and ten until 6th). On 4th, several at Southwold and two to three at Walberswick. Sixteen in the Blyth area, 5th to 1 Ith. Common Sandpiper (T. hypoleucos). On 3rd : small number at Lowestoft (some on tennis courts) ; many heard at Southwold ; sixty landed at Minsmere (not present next day). On 4th, heard at Sibton at 5.30 a.m. ; twenty-five at Walberswick ; forty at Shingle Street and several at Westleton. Redshank (T. totanus). On 3rd : many at Lowestoft and Southwold, 100 at Minsmere. On 4th : many still at Lowestoft, fifty at Walberswick but the Minsmere birds down to twenty-five. Spotted redshank (T. erythropus). Several heard at Southwold on 3rd ; fifteen at Walberswick on 4th. Greenshank ( T . nebularia). On 3rd : several heard at Benacre and Southwold. Sixty landed at Minsmere, this number reducing to forty on 4th and twenty on 5th and 6th. Forty at Walberswick on 4th. Knot (Calidris canutus). 100 at Minsmere on 3rd, down to sixtv on fourth and 5th. Twenty at Walberswick on 4th. Purple sandpiper (C. maritima). Six on a flooded tennis court and others elsewhere at Lowestoft on 3rd. Several still there and one at Walberswick, on 4th. Little stint (C. minuta). Twenty landed at Minsmere on 3rd, increasing to twentyfive on 4th and until 13th, then up to twenty until 6th October. One on rain puddles in the road at Westleton on 3rd (GH). Ten at Walberswick on 4th moved off south in the afternoon. Up to eight on the Blyth, 5th to 1 Ith. Temminck's stint (C. temminckii). Two at Minsmere on 3rd, three there on 4th and until 16th and one until 21 st. Two to three at Walberswick on 4th and one 5th/6th. Dunlin (C. alpina). On 3rd Lowestoft and Benacre ; 700 were 200 on 4th, 150 on 5th and many were local on 4th when

: many moving south at sea off landed at Minsmere where there 6th and 100 on 7th. At Lowestoft, there also 400 at Walberswick.


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Curlew sandpiper (C. testacea). Thirty at Minsmere on 3rd, twenty on 4th and 5th, ten on 6th and 7th. Three at Walberswick on 4th. Sanderling (Crocethia alba). On 3rd : a few were feeding with the other waders on flooded tennis courts at Lowestoft ; twenty landed at Minsmere. Some still present at Lowestoft on 4th but none at Minsmere. Ruff (Philomachus pugnax). On 3rd : only sixty were seen at Minsmere but on 4th and 5th there were at least 150, dropping to sixty on 6th and 7th. At Walberswick there were 350 on 4th, most leaving on 5th. Exceptional numbers at Havergate on 4th| when there were 100 on the Town Marshes at Southwold and thirty at Shingle Street. Up to 120 on the Blyth, 5th to 1 Ith. Red-necked phalarope (Phalaropus lobatus). gravel-pit at Westleton on 4th (MB).

One on a flooded

Arctic skua (Stercorarius parasiticus). Sveral at Walberswick on 4th and at Lowestoft on 4th and 5th. Great skua (S. skua). One or two at Lowestoft, 3rd to 5th (HEJ) ; one at Walberswick on 4th (GRB). Little gull (Larus minutus). rush on 3rd (HEJ).

Several at Lowestoft durintr8 the

Black tern (Chlidonias niger). On 3rd : one at Benacre, 150 at Minsmere and sixty at Havergate. On 4th : twelve at Southwold and ten moving south at Walberswick. Remained longer than any other species at Minsmere where up to twenty were present until 19th, c. fifteen until 23rd and four until 27th (HEA et al). Common tern (Sterna hirundo). Minsmere on 3rd. Little tern (S. albifrons).

150 came in with the rush at

C. twelve arrived at Minsmere on 3rd.

Sandwich tern (S. sandvicensis). C. twelve arrived at Minsmere on 3rd. Cuckoo (Cuculus canorus). On 4th : one at Benacre, two at Walberswick, three at Minsmere, one at Shingle Street. Swift (Apus apus). On 3rd : a flock of 300 came in with the other migrants at Minsmere and there were thirty to forty at Southwold Thirty at Walberswick on 4th. Wryneck (Jytix torquilla). That only few were seen on 3rd (one at Benacre, two at Southwold, two at Minsmere) could well have been due to the good Camouflage of these birds when sheltering in very bad weather. On 4th and 5th, an extraordinary number


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was disclosed : over thirty at Lowestoft (R.B 6t (il)> over twenty at Benacre (AGH), forty in the Walberswick area (DJP, GLC, FKC et al), ten at Southwold (GBGB), six at Westleton (MB, GH), twenty-five in 150 acres at Minsmere (HEA, RGHC, FKC et al), three together at Sizewell (HEA, PJM), and six between Sizewell and the north side of Thorpeness (CC, DM). With 150 individuals known at only eight points along a coast of c. twentyseven miles, it is evident that many hundreds must have arrived. At four places, forty-nine were trapped and ringed. Dßring their protracted stay, many singles began to be seen inland and further south, e.g., three on Sutton Heath on 5th and one at Bawdsey on 6th, two on 7th (GED), one at Tunstall on 7th, and one at Butley, Sept. 9th (PAB). Near the coast, numbers feil considerably on 8th, a few still being present at Walberswick on 16th and at Minsmere on 17th. Wood lark (Lullula arboreä). Four on the shore at Minsmere on 3rd and two on 4th (HEA et al). Song thrush (Turdus philomelos). Two came in from the sea at Minsmere at c. 5 p.m. on 3rd (HEA). Ring ouzel (T. torquatus). At Lowestoft Denes, four on 4th, two on 5th ; Benacre Pits, one on 3rd ; Southwold, one on 6th and 9th ; Walberswick, seventeen came in from the sea on 3rd and twenty were present on 4th ; Minsmere, three to five from 3rd to 5th ; Snape, one on 4th ; Bawdsey, one on 5th. Records of one to three in many places at about mid-September were probably relative to a second influx on more normal dates. Wheatear (Oenanthe oenanthe). The second most numerous small passerine, arriving on 3rd in greatest density at the north and south ends of the affected coast-line. Observations at various points suggest that an average of 4,000 per mile crossed the coast between Lowestoft and Minsmere, amounting to some 100,000 having arrived in the initial rush in the afternoon of 3rd. The species was apparently in better condition on arrival than the other small passerines and spread more quickly inland and to the south. Most resumed their migration during the night of 5th/6th and comparatively small numbers were present between lOth and 18th. Whinchat (Saxicola rubetra). The fourth most numerous small passerine, most occurring in the northern sector with c. 3,000 in one mile in the Lowestoft area and 1,000/mile at Walberswick and Minsmere. Departure was about as wheatear.


262 Transactions of the Suffolk Naturalists', Vol. 13, Part 4 Redstart (Phoenicurus phoenicurus). Easily the most abundant of all the drift migrants arriving on 3rd between Lowestoft and Minsmere, totalling more than 250,000. Large numbers were near exhaustion. Time and rate of departure was about as the other chats but many remained for a very long period, e.g., 100 still present at Minsmere on 15th. Black redstart (P. ochruros). Two at Southwold (GBGB) and three on the dunes at Minsmere on 3rd ; two at Aldeburgh on 4th (EFC) ; one at Southwold on 5th (RJR). Nightingale (Luscinia megarhynchos). One at Lowestoft on 3rd. In view of the Scandinavian/Baltic origin of most of the migrants involved in the arrival, this could, however, have been a Thrush Nightingale (L. luscinia). Bluethroat (Cyanosylvia svecica). The few ad. m. seen were of the red-spotted form. Extraordinary numbers of a species hitherto rare in Suffolk : Lowestoft, seven on 3rd and 4th (RB, RC, HEJ) ; Benacre, one on 4th (AGH) ; Covehithe, one on 3rd (DR) ; Southwold, two on 3rd and 4th ; Walberswick, c. twenty on 5th (fewer on 4th) (GLC, FKC, GJJ, DLP) and three were two miles inland on 5th ; Reydon, one on 9th. At Minsmere there were c. twelve on 3rd, twenty on 4th, twenty-five on 6th and 7th and last (two) on 13th, all in only 100 acres of marsh where individuals soon established and kept territories in damp corners of grass and reed at the edges of meres or along stretches of a muddy tractor path (HEA, FKC, RGHC, EH, PJM et al). Similar territorial behaviour was noted at Walberswick. Robin (Erithacus rubecula). Comparatively small numbers arrived between Lowestoft and Southwold but very many were concentrated between Walberswick and Minsmere, e.g., 400 on a three-quarter mile front at Minsmere on 3rd and 4th, 200 on 5th then a rapid further decline. No pale-breasted birds, from far distant breeding sites, were seen. Grasshopper warbler (Locustella naevia). Two at Southwold on 3rd (GBGB), one at Walberswick on 5th, one at Reydon on 8th (CDGC). Great reed warbler (Acrocephalus arundinaceus). Walberswick on 5th (DJP).

One

at

Reed warbler (A. scirpaceus). A few were present in Lowestoft and Southwold at sites where not normallv seen and there was an apparent influx at Benacre. Icterine warbler (Hippolais icterina). One at Benacre on 3rd and two more on 4th (AGH), two at Minsmere on 4th (HEA, RGHC, EH, PHM, FKC), one at Walberswick on 5th (RJR).


GREAT FALL

263

Blackcap (Sylvia atricapilla). One at Lowestoft on 4th and two on 5th ; one near the shore at Minsmere on 3rd (cf garden warbler). Barred warbler (S. nisoria). One at Lowestoft on 4th and 5th (HEJ), one at Walberswick on 6th (DJP) and l l t h (JHC). Garden warbler (5. borin). Most arrived in the Minsmere area with progressively fewer northwards to Lowestoft. Some 2,000 were still present at Minsmere on 4th then almost the entire arrival had gone by next day, in contrast to the other small passerine species most of which were still present on 5th. Whitethroat (S. communis). Relatively small numbers arrived of this species which is often the most common in peak-time " rushes ". Of the 200 at Minsmere and 150 at Lowestoft, most had departed by 5th and 6th. Lesser whitethroat (S. curruca). Only very small numbers, most at Lowestoft (more seen on 4th than on 3rd) (EWCJ, HEJ, FC) ; c. twenty at Walberswick on 4th and 5th and c. ten near the shore at Minsmere on 3rd. Willow warbler (Phylloscopus trochilus). The sixth most numerous small passerine with 500 each at Lowestoft and Minsmere on 3rd and 4th and fewer at intermediate points. ChiffchafF (P. collybita). Identified only at Lowestoft (HEJ) and Southwold (GBGB). No evidence of any arrival at the trapping stations where many willow warblers were caught. Goldcrest (Regulus regulus). At the shore : one at Minsmere on 3rd (EH) and one at Walberswick on 5th (DJP). Spotted flycatcher (Aluscicapa striata). Most, c. 300, arrived at Minsmere, almost none at Walberswick then good numbers again further north at Southwold and Lowestoft (100). Most stayed until 6th and 7th. Pied flycatcher (Af. hypoleuca). Throughout the affected area, the third most numerous passerine, totalling some tens of thousands. Density was irregulär along the coast, outnumbering other small species at Benacre (AGH) and with twice as many arriving in the Lowestoft area than at Minsmere and fewer at Walberswick. A large exodus occurred overnight on 5th/6th and hundreds moved inland up to c. twelve miles. Small number still present up to 19th. Red-breasted flycatcher (M. parva). One at Lowestoft on 4th (HEJ). One at Oulton on 5th (per HEJ).


264 Transactions of the Suffolk Naturalists', Vol. 13, Part 4 Meadow pipit (Anthus pratensis). Small numbers, many fewer than tree pipit, occurred at Lowestoft and Southwold on 3rd and 4th. Tawny pipit (A. campestris). One at Minsmere on 4th (HEA, RGHC PJM), three on the dunes north of Sizewell power Station from 5th to 8th (RVAM, HEA, GJJ, FKC et al) and one at 9th (HEA). Tree pipit (A. trivialis). Most, several hundreds, arrived in the Walberswick area, 150 at Minsmere and fewer elsewhere, e.g., twenty-five at Lowestoft. Many fewer were present on 5th, some still being seen on the coast on lOth. Rock pipit (A. spinoletta). Three at Lowestoft on 3rd (HEJ). Alba wagtail (Motacilla alba). A 6mall number at Lowestoft on 4th and a white wagtail still present there on 8th (EWCJ, HEJ, RB). Grey wagtail (M. cinerea). Four at Lowestoft on 3rd and 4th (EWCJ,HEJ). Flava wagtail (M. flava). A small number arrived at Lowestoft, Southwold, and Minsmere on 3rd and an increase was noted at Walberswick on 4th. Red-backed shrike (Lantus collurio). Small number in the south, most at Minsmere where five were seen on 3rd, ten were present from 4th to 7th (HEA, FKC et al), five on 8th and the last staying until 17th (HEA). Two at Southwold on 4th, one at Walberswick 6n 6th. Siskin (Carduelis spinus). C. forty arrived at the coast at Minsmere on 3rd and smaller parties occurred at Walberswick and Lowestoft between 3rd and 5th. Redpoll (C. flammea). Small groups arrived at Lowestoft on 3rd (HEJ). Chaffinch (Fringilla coelebs). A flock of twenty-five came in from the sea during the rush at Minsmere on 3rd (HEA et al). Brambling (F. montifringilla). 5th (GLC, DJP).

One caught at Walberswick on

Ortolan bunting (Emberiza hortulana). One at Minsmere on 3rd (HE^), three on 4th (EH) then at least one until l l t h (HEA). One at Benacre on 4th (AGH), one at Walberswick, 4th and 5th (GLC DJP), at least three at Covehithe on 9th (RVAM) and two lOth and l l t h (FKC,GJJ). TABLE

I

Main Passerine Species involved in the Landfall of 3rd September, 1965


265

GREAT FALL

Counts and estimates were made in approximately comparable areas : Minsmere : 3rd September. The figures refer to birds which arrived over three-quarters of a mile of coastline of the R.S.P.B, reserve from 1.15 to 7 p.m., most in the first hour (HEA, RGHC, EH, PJM). Walberswick : 4th September. 7 to 8 a.m., estimates in an area of three-quarters of a mile of coast to one-quarter of a mile inland—mainly open shore, pure reeds and bushes (GLC. DJP). Lowestoft : 4th September. An area of three-quarters of a mile of North Denes to one-quarter of a mile inland, to include the trees along the Denes Oval (BB, RB).

Wheatear Redstart Whinchat G a r d e n Warbier Willow warbler Pied flycatcher T r e e pipit

Minsmere

Walber swick

4,000 7,000 750 2,000 500 1,500 150

700 2,000 400 600 200 400 500

Lowestoft 2,000 5,000 1,500 300 500 3,000 25

Trapping In the week following the arrival on 3rd, some 3,000 Scandinavian passerines were ringed at five points between Lowestoft and Sizewell, including 5 0 0 + redstarts, 3 0 0 + garden warblers, 300+ willow warblers, and 4 0 0 + pied flycatchers, as well as forty-nine wrynecks. Within the next few weeks, four redstarts and one pied flycatcher were recovered in Iberia. The sample weights taken at two stations (see Table II below) show a considerable ränge within each species, most being lighter than average for these night migrants when trapped at early morning. Exceptionally, garden warblers, whitethroats, and willow warblers were of average weight or slightly heavy and evidently their good fat deposits enabled these three species to continue their migration more quickly than most of the other small passerines. Redstarts weighed in the early morning of 3rd, some eight hours before the great fall in the afternoon, were heavier tnan those trapped next day (birds were not weighed on the evening of 3rd because of the wet conditions). A comparison of weights on 4th with those on subsequent days showed a slight decrease amongst those birds still near the shore ; the heavier, stronger birds would have been able to move on more quickly than the lighter, weaker ones and several emaciated redstarts and flycatchers were in fact found dead in the coastal areas between 5th and 8th.


266 Transactions of the Suffolk

Naturalists',

Vol. 13, Part 4

TABLE II

Sample weights from Minsmere and Walberswick

Species

Sept.

Number in sample

Wheatear

Average weight (§•)

5th 6th Redstart 4th 5th-8th Whinchat 4th-7th Bluethroat Sth Robin Sth Garden warbler 4th 5th-8th » „

5 10 31 20 8 6 5 17 21

19 21 14 13 15 17 15 18 16

9 6 1 6 8 1 4 7 9

18 19 10 12 12 14 13 16 14

Whitethroat

7 9 13 7 35 16 19

19 15 16 9 9 13 10

6 6 0 3 4 0 8

15 13 13 7 7 11 9

»»

4th 5th 6th-8th W i l l o w warbler 4th 5th-8th Pied flycatcher 4th 5th-6th >>

Remarks on average weight

Range (g.) 0-22 6-23 8-15 0-16 5-17 0-18 5-16 5-22 0-21

0 8 8 1 8 5 5 0 5

Very Iight Light

Slightly heavy N o r m a l breeding weight 8-21 1 Very heavy 1-18 0 Slightly heavy 5-1H 6 9-11 5 5-11 1 2-14 4 L i g h t 6-12 0 Extremely light

Observers R. Briggs, B. Brown, R. Coleman, F. Cook, E. W . C. Jenner, H . E. Jenner, F. M u d d e m a n (Lowestoft area). A . G. H u r r e l l

(Benacre).

Miss D . Raikes (Covehithe). G. B. G . Benson, Miss B. A . Coney (Southwold). G . R. Bennett, G. L . Clarke, D . J. Pearson (Walberswick area). F. K . Cobb, G. J. Jobson (Minsmere,

Walberswick).

H . E. Axel], R. G . H . Cant, E. Hosking, P. J. Makepeace (Minsmere, Sizewell). R. V . A . Marshall (Benacre, Minsmere, E. F. Crosby (Aldeburgh,

Thorpe

R. J. Rhodes (Walberswick, Blyth,

Sizewell).

Meare). Southwold).

C. Cuthbert, D . M o w e r (Thorpeness, Sizewell,

Minsmere,

Westleton).

P. A . S m i t h (Leiston, Snape). M . Packard (Shotley). C. G . D . Curtis (Reydon). M r s . M . Bale, Miss P. Barlee, Miss G. Houghton (Westleton, Minsmere). D . W h i t e , B. E b r i t t (Tunstall, Sudbourne). R. J. Partridge

(Havergate).

F. J. French, G. J. Jobson

(Felixstowe).

P. R. Catchpole, G . E. D u n n e t t (Shingle Street, Bawdsey, Sutton Mrs. H . Cole

(Weston).

Heath).


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