[33] Migration is a voluntary, and not a compulsory, movement; and it must not be imagined that recurring bird waves actually push each other forward. Young Blackbirds and Thrushes leave some weeks in advance of the great rush of their continental allies; and it is well known that Woodcocks, which breed in Great Britain, leave in the autumn, before the arrival of the northern flights, a distinct interval elapsing between the two events—the going and the coming.
One of the last schedules received, at the time of going to press, from the Cockle L.V., off the Norfolk coast, records immense flights of Crows (probably Rooks), passing in a southeasterly direction to the Continent early in March, 1885, commencing on the 2nd at 7 a.m., in large numbers on the 6th at 6 a.m., and continuous from 6 a.m. to 8 a.m. on the 8th; large numbers again on the 9th at 5.30 a.m.
The notes under the head of separate species in the East Coast report for 1884, indicate several movements of special interest. Blackbirds, as has been already stated, have crossed the North Sea in extraordinary numbers, commencing on September 12th and throughout October, and immense numbers in November; on the 11th, 12th and 13th the rush appears to have been continuous, night, and day, over the whole coast line; after this intermittent to the end of the third week in January, 1885.
Another very interesting feature is the occurrence of the Arctic Bluethroat in considerable numbers between September 8th and 16th; eighty to one hundred were observed in one locality on the Norfolk coast on the 12th.
The migration of the Gold-crested Wren was very pronounced. The first are recorded on August 28th, and after this at various stations in large numbers up to November 22nd. Eighty-seven days against ninety-two in 1882, and eighty-two in 1883. The visible migration of this little wanderer across Heligoland has been considerably below the average of other years.
Pied Flycatchers arrived in large numbers from August 10th to September 17th. Across Heligoland also there was a great migration between August 10th and September 18th.
Immense numbers of Bing Doves are shown to have crossed from the Continent between the 21st of October and the end of November. This immigration appears to have covered the coast between Berwick and Yarmouth. On our northern coasts for nine days, between November the 20th and 28th, the rush was continuous. Large numbers of Stock Doves also crossed during the same period.
The main body of the Woodcocks generally arrive in two flights, known to East-coast sportsmen as the "first flight," and after this the "great flight." In the autumn of 1884 the immigration of this species was most prolonged, commencing on September 1st, and continued onward to January 20th, 1885, or 142 days. Four distinct rushes or flights are also indicated,—October 5th and 6th; another on the 10th to the 16th; a third, probably the "great flight," on the 28th; and again a very large flight between November the 11th and 13th. Independent of these there has been a constant dropping in by two or three together, or singly, throughout the autumn and winter. Woodcocks have also crossed Heligoland in the same desultory fashion; and the dates of the chief flights will be found to correlate closely with the rushes on to our East Coast.
In the latter part of November and early in December there was a considerable arrival of Bitterns on the East Coast, probably driven across by the severe weather on the Continent between November the 28th and December 2nd.
Besides the Bluethroats, already noticed, several rare and casual visitants have been recorded during the autumn. Two examples of the Barred Warbler, one at Spurn Point and another on the Norfolk coast. The Icterine Warbler, also on the Norfolk coast; and an Ortolan Bunting, likewise from the same locality. The Lapland Bunting, in Lincolnshire and Norfolk; Tengmalm's Owl, in Holderness; and a rose-coloured Starling, near Spurn.