REPORT ON THE MIGRATION OP BIRDS. 171 



The line of flight of the Anatidce is generally from N. to S., 

 as explained further on by Mr. Cordeaux. I may mention here 

 that this holds generally also on the west coast of Scotland, but 

 that the lines of flight of the Insessores are influenced by local 

 causes, and configuration and trend of the west coast. Thus the 

 direction, according to previous experience, is often from N.W. 

 to S.E. When migrating over or near land the lines of flight 

 follow the great valleys and then the coast-lines, often cutting off 

 promontories, as at the Boss of Mull. These are probably birds 

 having a starting-point more to the N.W., — the Hebrides, Iceland, 

 .and North America, — and others which in their migrations from 

 east to west overshoot the land and "hark back"; but we will 

 speak more of this in our remarks under "West Coast." Land 

 birds have passed at all hours of the day and night, flying 

 generally low, and in almost all kinds of weather. The Anatidce, 

 as a rule, fly much higher, and consequently are only seen, or 

 almost only, in clear weather. 



Almost all records of birds caught or killed, or striking at 

 the lanterns, are noted on dark or cloudy nights, with fog, haze 

 or rain, or snow and sleet. The isolated stations, such as the 

 Bell Eock, are most deadly ; many are stunned and killed, and 

 blown into the sea, at such localities. Birds on such nights often 

 remain around the lights all night or rest on the window-sills of 

 the tower and the balconies, or endeavour to obtain entrance to 

 the tower. Whenever dawn appears they resume their flight 

 towards the nearest land. 



A great northward rush appears to have taken place at Bell 

 Rock lighthouse between the 2nd and 11th of March, 1880, as 

 noted in the duplicate schedule by Mr. James Jack, lately received 

 by me. On the 2nd March great numbers of birds were seen 

 flying about the lantern, apparently of various species, of which 

 Blackbirds, Thrushes, and Mavises were recognised ; wind S., 

 light breeze, heavy sleet ; sexes unidentified ; a great number 

 continued to strike hard on lantern all night from 10 p.m., and 

 rebounding ofi", fell into the sea. On the 9th, great numbers, 

 including Lapwings, Thrushes, Mavises, " Snowflecks," Rooks and 

 " Sea-piets," from 5 a.m. till good daylight, when all disappeared 

 in the fog ; observer could not say in which direction they flew ; 

 wind S.E.J light breeze, fog, and rain. This has been the largest 

 migration seen this year; very large numbers of each species 



