188 THE ZOOLOGIST. 



generally renders it a difficult matter in arriving at any conclu- 

 sions as to what species, rare to Ireland, may have been migrat- 

 ing in company with the common species on some of these 

 diurnal flights. The evidence already given, regarding the 

 circumstances under which I collected the two Tree-Pipits,* 

 leaves little doubt in my mind that these two birds alighted 

 directly on the Eock in daylight, having abandoned their com- 

 panions as the latter passed by in the vicinity. On this point 

 I shall have something more to say presently. The speed at 

 which both Wagtails and Pipits flew was about twenty miles 

 an hour. I made my calculations, which I claim to be only of 

 approximate value, by measuring one of the major axes of the 

 Ptock, an axis which at the same time corresponded to a favourite 

 path pursued by the birds overhead. Then, with a stop-watch, 

 I noted in seconds the time taken by the birds in traversing this 

 axis. I took a vast number of these time-observations, and found 

 that in favourable weather, with light wind, the speed of flight 

 altered but little. The average height at which Meadow-Pipits 

 flew was about seventy feet or two-thirds the height of the light- 

 house tower. Wagtails flew higher, passing, as a rule, well over 

 the lighthouse dome ; and the average elevation was about one 

 hundred and twenty feet. However, the altitude of flight was 

 subject to considerable variation. 



As in the case of Meadow-Pipits, the chirp of Wagtails was 

 dominant and oft repeated, thereby affording me much aid in 

 distinguishing the different species flying past. 



Swallows, in making a diurnal passage, swept by the Eock 

 with rapid twisting flight. They did not seem to heed my 

 presence, and often flew close over my head. Now and again a 

 bird or two would forsake its companions and take up a 

 circuitous route round the Eock for the greater part of the day, 

 all the while hawking for insects. Only very exceptionally 

 would a bird alight; when it did it was usually for the pur- 

 pose of seeking shelter in a large cavern-like crevice. Very 

 different was the case when Swallows, affecting a nocturnal 

 journey, were held up at the lantern in thick weather. These 

 birds, possessed of a marvellous faculty for not striking, wearied 



:;: Vide " Discovery of the Tree- Pipit on the Tuskar Rock, Co. Wexford," 

 1 Irish Naturalist,' vol. xxi. November, 1912, pp. 209-213. 



