260 BRITISH BIRDS. 



pond " have afforded several interesting records. Of those 

 that took the westward route (c/. British Birds, Vol. III., 

 pp. 207-220), two were recorded from Norfolk and the Isle 

 of Wight respectively, as already noted in these pages (III., 

 pp. 220-399), and one reached the Balearic Isles. Those that 

 went south overland seem to have gone less far than in 

 former winters ; more definite information of this sort would 

 be of undoubted value, and it is quite within the possibili- 

 ties of the method. An interesting record also, has just 

 been discovered in a Russian paper, of a Gull hatched and 

 marked at Rossi tten in 1905 and shot at a colony near 

 Libau (Russia) — 95 Enghsh miles away in a northerly 

 direction — on June 20th, 1907. 



Several hundred Herring-Gulls (L. argenfatus) were marked 

 in 1909 on the great protected colony on the Memmert on the 

 North Sea coast. Owing to the great amount of shore- 

 shooting in that region the terrible proportion of 10'6 per 

 cent, was recovered in the fir&t winter. Of the 71 birds, one 

 had travelled 128 miles, one 100, and the rest 73 or less ; no 

 evidence of real migration. 



Of the others, tlis Dunlins [T. alpina) marked on passage 

 at Rossitten in early autumn, have proved of special interest. 

 The Essex record has already been noted in British Birds 

 (III., J). 293) ; it extended the route already marked by 

 several records (c/. II., p. 367) westwards along the south 

 coast of the Baltic. A still further extension is to the mouth 

 of the Gironde on the west coast of France, and again (since 

 publication of the report) to near the mouth of the Rhone on 

 the south coast. The theory that these points trace out a 

 route is based on the assumption that there is a single, fixed, 

 and definite route. This may seem unsatisfactory, but of 

 course it is merely a provisional hypothesis which remains to 

 be contradicted or confirmed and elaborated by later records. 



Lastly, Dr. Thienemann gives an account of a very 

 elaborate series of observations made in the autumn of 

 1909, on the velocity of migratory flight. Direction and 

 strength of wind, and inclination to line of flight, and all 

 such factors, have been duly taken into consideration. We 

 can quote only the average results for the various species, 

 approximately calculated to English miles per hour : — Hooded 

 Crow, 31;^ ; Rook, 32J ; Jackdaw, 38|; Starling, 46^; Sparrow- 

 Hawk, 25| ; Peregrine Falcon, 37 ; Lesser Black-backed 

 Gull, 31 ; Great Black-backed Gull, 31;^ ; Chaffinches and 

 Bramblings, 32| ; Siskins and Linnets, 34| ; and Crossbills, 37^. 



A.L.T. 



