VELOCITY OF THE MIGRATION FLIGHT 67 



in undiminished multitudes and while still subject to the full force 

 of the migratory impulse, whereas in the high northern latitudes 

 which it has been Dr. von Middendorff s good fortune to investi- 

 gate, the spring migration of many species either terminates, or, at 

 any rate, is approaching its close. It no doubt often happens that 

 birds relax their normal migration speed and advance more slowly 

 in these high northern latitudes, owing to their breeding quarters 

 close at hand not yet being in the enjoyment of a summer tem- 

 perature; but too many facts of a conflicting nature prevent us 

 from accepting the statement of the last observer that the average 

 distance accomplished by migrants per day is thirty-two geograph- 

 ical miles. If such were the case, species wintering, for instance, in 

 Middle Egypt and breeding within the Arctic Circle, would require 

 nearly three months for their migration journey, which, in itself, is 

 out of the question, and, moreover, contradicted by the already 

 instanced case of the Bluethroat. If this bird travelled at the slow 

 rate above indicated, one ought to meet with it during its spring 

 migration in Italy and the whole of Germany as numerously as in 

 Heligoland ; whereas, as already stated, it has been met with only 

 as an extremely rare and exceptional occurrence in all the countries 

 situated between this island and its winter quarters. 



Almost all the instances of migration velocity hitherto adduced 

 in evidence relate to the spring migration which birds are known 

 to perform with considerable haste. The desire to reach the 

 nesting homes is, however, by no means the only stimulus pro- 

 vocative of these extraordinary feats of flight; for the journey to 

 the winter quarters, in which less haste is manifested, likewise 

 affords a sufficient number of proofs, both as to the velocity of 

 bird-flight generally, as well as to the actual daily speed at which 

 their migrations are performed. In this connection we may con- 

 sider somewhat more hi detail the already- mentioned case of the 

 Hooded Crow. This bird, which, without question, must be classed 

 among the less expert flyers, travels in autumn in innumerable 

 droves across Heligoland and past both sides of the island. The 

 first flocks arrive at about eight in the morning, and are succeeded 

 in undiminished numbers by flock upon flock until two o'clock in 

 the afternoon, all travelling, without interrupting their flight, in a 

 westerly direction. 



According to the reports of my esteemed friend, John Cordeaux 

 with whose observations, conducted on the opposite east coast of 

 England, I am in the habit of regularly comparing my own the 

 first flights arrive at that coast about eleven in the morning, and 

 the last at about five in the afternoon, the latter being followed 

 sometimes by solitary stragglers. It has been repeatedly shown. 



