Letters, Announcements, fyc. 333 



the estuary, and found on that occasion between 150 and 200 

 Glaucous Gulls flying about in the immediate vicinity of 

 Kincardine, besides a number of Iceland Gulls, the two species 

 being easily recognized as they flew past. The first-named 

 bird has a soft Owl-like flight, which is very different from 

 that of the Great Black-backed Gull ; while the Iceland Gull 

 is distinguished by its quick flapping motion, resembling the 

 flight of some of the larger Terns. After examining upwards 

 of twenty Glaucous Gulls, shot in the Firth between the date 

 I have given and the 4th of January, I find the following 

 results : — I. Size extremely variable, the total length ranging 

 from 25 ^r inches to 30 inches, and the breadth from 58 to 64 

 inches. II. The birds were chiefly in the plumage of the 

 first year, the proportion of adult birds being even less than 

 in the case of the Kittiwake. The same variation occurs in 

 the measurements of the Iceland Gull, so far as I can judge 

 from an examination of four or five specimens which have 

 been shot by my friend Mr. Harvie Brown. 



This unprecedented influx of Sea-Gulls is evidently due to 

 the presence of shoals of sprats or garvies (Clupea sprattus), 

 which at full tide swarm near the surface. The fish are taken 

 in very large quantities in the firth, and disposed of in cart- 

 loads to the farmers in the neighbourhood, who use them as 

 manure. No doubt, I think, need be entertained as to the 

 origin of the invading Gulls. They can scarcely be regarded 

 as offshoots from British nurseries ; indeed the presence of 

 so many Glaucous and Iceland Gulls clearly shows that they 

 are migrants from arctic waters. 



I am, Sir, yours, &c, 



Robert Gray. 

 Glasgow, January 9, 1873. 



The following extracts are from a letter received from our 

 Editor, dated " Off St. Domingo, May 3rd." 



"We have had a first-rate passage, so far as regards weather, 

 but one very destitute of ornithological interest. Starting as 

 we did, in the middle of April, I certainly thought we should 

 come across a good many migratory birds in the Channel and 



