The Zoologist/4th series, vol 1 (1897)/Issue 672/Stone Curlews as observed around Thetford

by William George Clarke

 

STONE CURLEWS AS OBSERVED AROUND
THETFORD.

By W.G. Clarke.

 

The first Stone Curlew graphically described to British ornithologists was a specimen killed near Thetford in 1674, a drawing of which was forwarded to Ray by Sir Thomas Browne of Norwich. Since that time the "breck" district of Norfolk and Suffolk, of which Thetford is the centre, has been known as the great stronghold of this bird in Britain. Although the number of Stone Curlews breeding in the district has doubtless greatly diminished since that period, it still seems probable that the numerical loss has been little since the time of Salmon in the early thirties. This year they are certainly far more plentiful than they have been during the last ten years. A belt of heathland from four to eight miles wide surrounds Thetford—which for this reason has been designated "the town on the heath"—and hereon the Stone Curlews nest yearly.

J.D. Salmon, F.L.S., recorded the first arrivals of the bird in the district as on March 27th, 1834; March 15th, 1835; and March 28th, 1836. My own dates are April 2nd, 1892; March 31st, 1893; March 28th, 1894; March 31st, 1895; and March 24th, 1897. This year, however, they were noted by a very accurate observer at Great Fakenham, Suffolk, during the last week of February. The main body has generally departed by the middle of October, but Salmon started one on December 9th, 1834, and on December 12th, 1894, I distinctly heard one whistling almost incessantly for fifteen minutes from Barnham Cross Common, a mile from Thetford. A pair were also observed here in March, 1853, during deep snow.

On March 25th last, the day after their arrival in the district, these birds seemed to be extremely plentiful upon the heaths and upland "brecks" north and west of Thetford. Their whistling was almost continuous, albeit blurred, as it always is for a few weeks after their arrival. During this period, too, they seem to frequent the uplands by night in preference to the riverside marshland, their querulous notes sounding from all quarters. After this period, when the duties of nidification are in full swing, these birds may be seen following their accustomed lines of flight from the heaths to the river side, generally about two hours after sunset. Stevenson was unable to determine what amount of truth there was in this nocturnal "flighting" to the alluvium, but it is an undoubted habit in this district. Although the Stone Curlew is a bird of extreme wariness, it is possible on Thetford Warren to get within ten yards of flocks numbering from twelve to twenty in the months of May and June. In the 'Fauna of Norfolk,' Lubbock says that they were sometimes observed in flocks of from eighty to a hundred prior to their autumnal migration, but personally I have never seen a flock containing more than twenty-five. This may possibly be accounted for by the fact that, whereas in Lubbock's time the country was practically bare, and formed one vast heath, now, by the extensive planting of quick-growing trees, numerous plantations divide the heathland into sections, and it may be that only the birds of these smaller sections at present collect together, where of yore their area was much more extended. These flocks may be seen and heard together in the daytime, but after dark one never hears more than a pair calling together from any one quarter. A commonly accepted idea is that the Stone Curlew is disinclined to utter its note during the day, but is with regard to whistling essentially a bird of the night. In this district they always when disturbed,—whatever the hour of the day,—fly off whistling. Another curious fact may be noticed during a shower of rain in summer. A few minutes after the commencement of the downfall the majority of the Curlews fly down from the upland heaths to the nearest water, where I presume the rain has the effect of driving their food out of its haunts, thus enabling them to more easily capture it. From Knettishall and Stonehouse Heaths, and Thetford Warren and Abbey Heath, these birds fly down to the Little Ouse river, but on the heaths north of Thetford—Roudham, Bridgham, Wretham and Croxton—the Curlews invariably fly towards the meres, which are small sheets of water situated in the wildest portion of the Norfolk heathland. This, however, is more noticeable late in the season, in August and September, when they may find greater difficulty in always obtaining a sufficient food-supply by night. Each individual seems to whistle its loudest during this day-time flight to the feeding-grounds.

Their whistle has several variations soon after their arrival. Until May it is blurred, and often consists merely of a hoarse chuckle incessantly repeated for a short time. But about the first week in May their note is "curlew"; first short and indistinct, and then shrill and continued, the first short note being gradually dropped until only the full note remains. It has been suggested that their whistling by night is a call to inform one another of their whereabouts during cloudy weather. My own experience is that they are incomparably more noisy on moonlight nights than when the sky is overcast, and that therefore this reason is not the correct one. In this district the brood is generally hatched off by the commencement of June; but so well do the colourings of the young birds harmonise with those of the heathland that it is a matter of extreme difficulty to detect them. The eggs are usually laid in a slight hollow, sometimes on the open heath, but more generally on the upland "brecks." There is no material for the nest save a few of the previous year's dried bracken fronds, and search how one will, it is practically only by accident that the two eggs can be found. After the young ones are hatched it seems to be their rule to take care of themselves on the approach of danger; their parents doing likewise. It is at this time that one or other of the parent birds may occasionally be seen with head and neck extended, as in the beautiful life-group in the British Museum of Natural History. A remarkable fact of the authenticity of this nest and its surroundings struck me as a prehistoric archæologist. On the slab of heathland turf is a prehistoric flint flake, such as one may find on any of the local heaths. Locally the Stone Curlew is generally called the "Cullew," but is occasionally termed the "Sandpiper" or "Willie Reeve."

What effect the planting previously mentioned may have upon the Stone Curlew cannot yet be determined; but certainly the more heathland there is covered with trees the more circumscribed must their haunts be in future. One cannot but hope that this characteristic breckland bird, with its once-heard but never-forgotten whistle, will long continue to occupy the haunts of its extinct companion, the Great Bustard.