THE BIRDS OF HELIGOLAND 207 



astonishing how exact they are in discovering the particular 

 potatoes that have not 3'et sprouted, or in some way or other pick 

 out the spot where they are buried in the ground to a depth of 

 about three inches. The birds do not by any means rummage 

 about till they find a potato, but dig their beaks exactly into the 

 spot where one is buried. They appear, therefore, merely to be 

 guided by an extremely keen sense of smell. In the autumn this 

 sjx'cies continues to pass through this island till very late in the 

 season, sometimes even after frosty weather has set in. Contrary to 

 the habit of the preceding species, which alights here only in excep- 

 tional cases, the Rook very frequently interrupts its journey on this 

 island, the flocks dispersing over the upper plateau of the rock in 

 search of food. But, Hke the preceding species, and perhaps in a 

 greater degree still, flocks amounting to thousands in number, may 

 be seen on fine calm spring days passing across the island at such 

 a height that they appear no larger than very minute specks. Often 

 indeed they entirely disappear from sight, and only their calls, still 

 faintly audible from above, give indication of the vast crowd of 

 wanderers speeding on their way at heights far above the range of 

 human vision. 



The breeding range of the Rook extends from England and 

 northern France, through Germany, up to central Scandinavia, and 

 in the same latitude through and beyond central Asia. 



41. — Jackdaw [Dohle]. 



CORVUS MONEDULA, Linn. 



Heligolandish : Kaiik. Name for Jackdaw. 



Corvus monedula. Naumann, ii. 93. 

 Jackdaw. Dresser, iv. 523. 



Corbeau choucas. Temminck, Manuel, i. 1 1 1, iii. 60. 



This meriy little bird occurs here in greater or smaller com- 

 panies during the two migration periods of the year. Frequently 

 too it travels in swarms, numbering thousands of individuals, 

 with which those of related species may or may not be mixed, 

 at a great height past and across the island. Sometimes small 

 companies make a day's stay, but in most cases they pursue 

 their journey without taking any further notice of Heligoland. 

 Frequently too a densely-crowded flock of from eighty to a hundred 

 individuals will come rushing, at lightning speed, and at a low 

 elevation, through the streets and among the hou.ses, disappearing 

 again later on. At other times they may be seen sitting calmly, 

 and crowded together in a row, on the weathercock of the church 



