232 STUDIES IN lilRD-MIGRATION 



perish, even in its most favourable areas, during an 

 abnormally protracted winter. It has already been 

 stated that Ireland ordinarily receives numbers of 

 Skylarks in autumn, and as it is again sought by 

 multitudes of refugees from the snows and frosts of 

 Great Britain, it follows that the Skylark population of 

 Ireland is at its maximum at a period when that of 

 Great Britain is at its lowest. 



When the winters are exceptionally severe on the 

 Continent, there is a renewal of the movements of 

 Skylarks (together with Starlings and Lapwings) 

 across the southern waters of the North Sea to the 

 south-east coast of England. 



During these cold-weather movements, many of the 

 emigrants perish at the lanterns of the light-stations. 

 Thus, on 2nd December 1882, the Bell Rock light- 

 house was visited by what is described as being the 

 greatest multitude of Skylarks ever known. It was 

 impossible to estimate the number, but they were 

 " striking hard for a couple of hours like a shower of 

 hail." 



If the statement that the winter emigration depends 

 wholly on the state of the weather needs any confirmation, 

 it may be furnished by the fact that in the mild seasons 

 1881-82 and 1885-86 very little was recorded. There 

 are, however, usually spasmodic and partial movements 

 in November ; but it is not until cold weather sets in 

 that any general exodus takes place. If there has been 

 much snow in December, as in 1879 and 1882, there is 

 little or no movement later in the season, because the 

 birds have already departed. On the other hand, after 

 the uneventful December of 1880, there were pronounced 

 emigrations in January 1881, when a cold period set in. 



