86 The Irish Naturalist. August, 



NOTES, 



ZOOLOGY. 



Variation in Size of Eg:gs of the Little Tern. 



With reference to Mr. F. W. Jeffers' note (p. 52 ante), fifteen eggs of 

 this species which I had opportunity of measuring were fairly uniform in 

 size, ranging from i- 24 inch — i- 3 inch in length by • 9 inch — • 97 inch in 

 breadth — averaging i- 264 inch by • 939 inch. When on the Clare Island 

 Survey in company with the late R. J. Ussher, we found 25 nests of this 

 species on an island — merely a sandy spit at high tide — in Clew Bay 

 (R.I. A. Proc, vol. xxxi, Sect. 2, p. 40). Most of these nests contained from 

 I to 3 eggs, but none of them were taken nor measured. My recollection, 

 however, is that they all appeared of normal size. I possess two eggs, 

 taken in Co. Down, which measure i- 5 inch by i* 05 inch and i- 44 inch by 

 I inch, respectively. These were submitted to the late H. E. Dresser, 

 who was of opinion that they were abnormal eggs of the Arctic Tern, the 

 eggs of which average about i • 6 inch by i inch. 



Nevin H. Foster. 

 Hillsborough, Co. Down. 



^ Swifts in May, 1923. 



The Swift was first observed here this year on 3rd May, when about 8 

 were observed, but during the next few days there were further arrivals 

 till the number reached about 40—50. In the following week arctic 



conditions prevailed and continued for a fortnight, This caused an 

 almost disappearance of the Swifts^ — some days none were seen, generally 

 2 or 3 were on the wing, and one evening 7 were observed. With the advent 

 of the fourth week, weather conditions improved, and gradually the 

 number of Swifts increased, though I consider that there are now, 3rd 

 June, barel}^ as many as were present about the beginning of second week 

 in JNIay. I think this cold snap with biting northerly winds was general in 

 Ireland during this period, and wonder if a like disappearance of Swifts 

 has been noticed in other districts. 



Nevin H. Foster. 

 Hillsburgh, Co. Down. 



I noticed a very similar disappearance of most of the Swifts in Dublin 

 from May 9th to i6th, after their arrival in force on the 3rd, and a like 

 diminution in numbers was observed by one of my brothers in Liverpool 

 about same time. I suspect the birds do ze away a good part of the cold 

 weather in their sleeping holes, but some further notes from other observers 

 would be of interest. 



C. B. Moffat. 

 Dublin. 



