146 MIGRATION. 



have now the greatest reason to suppose it does these 

 chafers, I no longer wonder at the use of its middle toe, 

 which is curiously furnished with a serrated claw. 



Swallows and martins, the bulk of them, I mean, have for- 

 saken us sooner this year than usual ; for, on September the 

 22nd, they rendezvoused in a neighbour's walnut tree, where 

 it seemed probable they had taken up their lodgings for the 

 night. At the dawn of the day, which was foggy, they rose 

 all together in infinite numbers, occasioning such a rushing 

 from the strokes of their wings against the hazy air, as 

 might be heard to a considerable distance ; since* that, no 

 flock has appeared, only a few stragglers. 



Some swifts staid late, till the 22nd of August ; a rare 

 instance ! for they usually withdraw within the first week.* 



On September the 24th, three or four ring-ousels appeared 

 in my fields for the first time this season. How punctual 

 are these visitors in their autumnal and spring migrations ! 



LETTER XL VIII. 



TO THE HON. DAIKES BAREINQTON. 



SELBORNE, February 8, 1772. 



DEAR SIR, "When I ride about in winter, and see such 

 prodigious flocks of various kinds of birds,t I cannot help 

 admiring at these congregations, and wishing that it was in 

 my power to account for those appearances, almost peculiar 



* See Letter xcvir. to the Hon. Daines Barrington. 



"j* Mr. Bennett seems to think that the flocking of birds in winter is 

 occasioned by hunger. Starlings, finches, linnets, and other birds, however, 

 flock early in the autumn when food is plentiful. I have always thought, 

 however, that birds flock by a benevolent arrangement of Providence, for self- 

 preservation. Whenever they are gregarious, they are much more easily 

 alarmed than when there are only a few together. Thus it is well known to 

 sportsmen that when partridges and grouse assemble in large packs, it is very 

 difficult to get within shot of them. Besides many gregarious birds, such as 

 rooks, wood-pigeons, &c., plant sentinels on a tree who give an alarm when 

 danger is apprehended. Large flocks of wild geese and ducks are generally 

 very wild. ED. 



