200 THEIR NUMBERS FLUCTUATE. [P ART II* 



increase in the cultivation of the turnip-crop, the 

 immigrants, finding that there was an ample 

 supply of food for them, as well as the native 

 birds, and finding the place suit them in other 

 respects (as, for instance, affording plenty of 

 covert, and that, or at least a large proportion of 

 it, but little disturbed), were induced to prolong 

 their stay throughout the winter, and thus became 

 naturalized there. 



Their numbers still occasionally vary. During 

 the years 1849 and 1850 I noticed that they ap- 

 peared to be not nearly so numerous as during 

 some preceding and the subsequent years. Why 

 this should have been the case I do not know, for 

 there was no perceptible diminution in the usual 

 turnip-crop, nor apparently any other reason by 

 which it could be accounted for. 



Still, each year, about the end of October or 

 the commencement of November, a large propor- 

 tion of the Woodpigeons appear to leave the island, 

 returning again in about two months to their old 

 haunts. During this period they are, I have but 

 little doubt, absent on an excursion to the New 

 Forest in search of beech-mast, perhaps their 

 most favourite food, which is supplied there in 

 greater quantities than the Island affords, and 



