Birds by Land and Sea 



time they began to congregate, forsaking the chimneys 

 and houses, they roosted every night in the osier beds 

 of the aits of that river (the Thames). Now, this 

 resorting toward that element, at that season of the 

 year, seems to give some countenance to the northern 

 opinion (strange as it is) of their retiring under 

 water." 



Writing again in February of 1769, he states : 

 "If ever I saw anything like actual migration, it was 

 last Michaelmas Day. . . . We were then on a large 

 heath, or common, and I could discern, as the mist 

 began to break away, great numbers of swallows 

 clustering on the stunted shrubs and bushes, as if 

 they had roosted there all night. As soon as the air 

 became clear and pleasant, they all were on the wing 

 at once ; and, by a placid and easy flight, proceeded 

 on southward, towards the sea. After this I did not 

 see any more flocks, only now and then a straggler. 

 I cannot agree with those persons who assert that the 

 swallow kind disappear some and some, gradually, as 

 they come ; for the bulk of them seem to withdraw 

 at once ; only some stragglers stay behind a long 

 while, and do never, there is the greatest reason to 

 believe, leave this island. Swallows seem to lay 

 themselves up, and to come forth in a warm day, 

 as bats do continually of a warm evening, after they 

 have disappeared for weeks. For a very respectable 

 gentleman assured me that, as he was walking with 

 some friends under Merton wall on a remarkably 

 hot noon, either in the last week in December or 



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