EXCEPTIONAL MIGRATION PHENOMENA 119 



year at which these birds make their appearance i.e. almost exclu- 

 sively in June and July partly by the motive which prompts their 

 migratory flight. 



When we consider the time of their appearance, and the fact 

 that they are, almost without exception, old breeding birds, we may 

 perhaps, as already intimated above, not have far to seek for the 

 motive which prompts these south-eastern species to take up anew 

 their migratory journey ; at a time when their spring migration 

 ought to be at an end ; and thereafter to continue it in the same 

 north-north-westerly and north.- westerly direction which had been 

 pursued by them during the latter movement. The only explana- 

 tion of this irregularity may probably be found in the assumption, 

 that all such summer visitors are individuals which have lost their 

 spouses during the earlier stages of the breeding season, and which 

 have then sought to satisfy the persistent impulse towards accom- 

 plishing the act of propagation, by proceeding farther in the same 

 direction which they had previously pursued during the said spring 

 migration. This view derives considerable support from the fact 

 that most of these birds are old males, who are less exposed to the 

 risk of falling victims to birds of prey than the females, since the 

 latter, while sitting on the nests, engaged either in laying or hatch- 

 ing their eggs, are much more liable to meet with a fate of this 

 description. 



A consideration of the regions which are inhabited by these 

 species during the summer and winter months absolves us from 

 the necessity of furnishing a proof of the fact that their spring 

 migration proceeds in a north-westerly direction ; nevertheless, in 

 regard to such of these species as occur more numerously, a few 

 instances, such as the following, may be brought in evidence. 

 The Rose-coloured Starling, which in favourable weather is seen 

 here almost every summer, breeds very numerously in Asia Minor, 

 the Crimea, and the Caucasus, and winters in myriads in the east of 

 India. The Black-headed Bunting (Emberiza melanocephalcC), 

 which I have obtained here about fifteen times, nests in Greece and 

 Turkey and Asia Minor, and has its winter quarters in the east of 

 India. In the case of the Short- toed Lark, which I have handled in 

 the fresh state from forty to sixty times, though its breeding range 

 extends too far west to be of much value to the question under 

 discussion, there can nevertheless be little doubt that the examples 

 which have occurred here from the middle of May to July origin- 

 ated from Greece and the neighbouring districts. I have, however, 

 also obtained various examples of this small Lark in completely 

 moulted plumage during the autumn migration, which, considered 

 in the light of analogous occurrences, could only have reached 



