.Mr. W. Thompson on the Birds of Ireland. 173 



erted to the utmost*. Similar evolutions, in which a much greater 

 number of these birds participated, were witnessed on the 24th inst. ; 

 the weather being similar to what it was on the 22nd, in regard to 

 fineness and a cloudless sky. The barometer was very high and sta- 

 tionary on both evenings. The state of the barometer and weather 

 has been mentioned, that some idea may be formed whether or not 

 the atmosphere could have been "highly electrical" throughout the 

 varied weather described, or indeed daily throughout that of any two 

 months in this climate f. 



Swifts prefer to nestle in lofty edifices, especially when in a state 

 of dilapidation J ; but in the north of Ireland, where these do not 

 often occur, they content themselves with more humble dwellings. 

 I have remarked that in many of our northern towns §, where swifts 

 are as plentiful as in any country, that they select for their domicile 

 the eaves of the oldest houses, or those from which the fast encroach- 

 ing spirit of improvement has not yet banished the thatched roofs. 

 On the 8th of July 1833, I observed many of these birds flying un- 

 der the eaves and clinging to the walls of occupied two -story houses 

 of this kind in the town of Antrim, and although they and the mar- 

 tins appeared an indiscriminate multitude when flying about the 

 street, their places of nidification were quite distinct, the martins 

 building on the south, and the swifts confining themselves to the 

 north side : on a house just opposite the chief abode of the latter, I 

 reckoned about twenty nests of the martin. When in the town of 

 Ballymoney, on the same day, several swifts were observed to fly 

 under the thatch of a house similar to that described, whilst against 

 it appeared some inhabited nests of the martin. On the 24th of June 

 1 834, the swift was remarked to have similar nestling-places in Lis- 

 burn and Banbridge. In all the above-mentioned localities these 

 birds were flying about in groups and screaming violently, the wea- 

 ther being delightfully warm, and the sky not only " purely beau- 

 tifully blue," but not a cloud visible. For a week after the former 

 date the weather continued very warm and dry. 



In Belfast, where houses such as those described are not to be met 

 with, I have known the swift's nest to be placed under the window- 



* Mr. Macgillivray remarks, " that the loudest and most frequent cries 

 are heard when birds are evidently in active and successful pursuit." At 

 the times above alluded to they certainly were not feeding. 



f Mr. Macgillivray, in his ' British Birds,' vol. iii. pp. 619 and 622, enters 

 fully into the subject of the swift's screaming. His observations of 1837 

 very generally agree with mine, made a few years before. Dr. J. I). Mar- 

 shall, in his memoir on the Statistics and Natural History of the island of 

 Rathlin, where swifts are plentiful, states, that the result of his observa- 

 tions is opposed to the views of White and Selby. He believes the loud 

 screaming of these birds to be particularly induced by fine weather and an 

 abundance of food. 



% When on Ram's Island, in Lough Neagh, in the month of June 1833, 

 I remarked several of these birds flying in the vicinity of the ancient round 

 tower, whose " rents of ruin" were most probably their temporary abiding 

 place. 



§ Swifts especially delight in large open spaces in towns. 



