231 



THE TWITE {Linotajlainrostns). 



Several Twites were noticed passing south on the soutli coast of Yoik- 

 shire on the 25th and 2C)th of October. 



THE CROSSBILL {Loxia curvirostm). 



Although not strictly within the bounds of our investigation, mention 

 should be made of the irruption of Crossbills that took place throughout 

 the country during the autumn of 1909. The movement, which was very 

 well marked, was first noticed on the Faroes and Shetlauds during the 

 last week of June, when many birds, both old and young and of both 

 sexes, made their appearance. These individuals or subsequent arrivals 

 remained in these unaccustomed localities from two to five weeks, sub- 

 sisting on various abnormal foods, such as unripe crowherries, grass-seeds, 

 thistle-heads, daisy-centres and sea-pinks. Tliroughout Scotland, and 

 still more noticeably throughout England, especially in the eastern 

 and southern counties, with the exception of Devonshire and Corn- 

 wall, these wandering birds appeared early in July and remained 

 in some numbers till the end of the year. Thei-e can be little 

 doubt that many simply passed through this country, while others, 

 finding suitable food and environment, settled down and commenced to 

 breed early in the following year. In some localities they were only seen 

 occasionally at more or less lengthy intervals, whereas in other places tbey 

 seem to have settled down early in the autumn. As the period treated 

 of in this Report only covers the first arrival, it would be out of place at 

 present to discuss either the possible causes of this immigration or tlie 

 results which have followed from it. We are, however, of opinion that 

 if the true cause of these sporadic irruptions of certain species were 

 known, we might have a clue to the beginnings of the migratory instinct. 



This particular irruption seems to have covered a large portion of 

 Europe, and the fact that several Two-barred Crossbills {Loxia bifasciata) 

 accompanied their commoner allies seems to indicate that it had its 

 origin iu N.E. Russia and Siberia. This points to the general direction 

 of flight having been a westerly or south-westerly one, which is still 

 further borne out by many individuals having reached the Flaunan Isles 

 and Western Hebrides, Avhile still unrecorded from the north of Scotland. 

 Birds were also observed crossing the North Sea and many were taken 

 at the Outer Dowsing Light-vessel, some miles from the Lincolnshire 

 coast, which again points to a marked westerly trend. 



Herr Ritter von Tschusi zu Schmidhofien, a well-known Austrian 

 ornithologist, is working the matter out thoroughly, a'ld we shall look 

 forward with interest to his conclusions. As far as this country is 

 coucerned, all notes and observations on this species have been collected 

 and published from time to time in Wltherby's ' British Birds,' to 

 which periodical we would refer those in search of the full details. 



