NOTES AND QUERIES. 393 



the flock of birds would concentrate and swoop down, and thus 

 drive it away, this being repeated as far as could be seen. Every one 

 of the party expressed the opinion that it was the most interesting 

 sight of its kind he had ever witnessed. Mr. Fred Booth, of Saltaire, 

 records, in the ' Yorkshire Observer,' that lately he saw a flock of 

 Swallows mobbing a Sparrow-Hawk near Bingley. On September 

 12th I noticed a Swallow's nest in a pig-cote, which contained un- 

 fledged young. On inquiry I ascertained the young left the nest on 

 or about the 21st of that month, after which they- lingered round the 

 place where they were reared for three or four days, and then dis- 

 appeared altogether. About this time they nearly all left the 

 district, although their food must have been nearly as abundant as 

 any time during the past summer. They were flying about Sher- 

 wood Forest on Saturday (September 24th) in some numbers, accom- 

 panied by House-Martins. I think it can be safely said that both 

 the Swallows and House-Martins are here double-brooded to a 

 large extent, but not the Sand-Martin. One would, however, be 

 inclined to think that the latter species is more likely to be double- 

 brooded than either of its two relatives. The Sand-Martin is decidedly 

 a more early arrival to this country than its allied species, but it is 

 no less true that it leaves earlier. — E. P. Butterfield (Wilsden). 



Great Crested Grebe Rearing Three Broods. — On Sept. 11th, on 

 the ponds in Eichmond Park, I saw a pair of Great Crested Grebes 

 (Podicipes cristatus) with two recently hatched young ones. A keeper 

 with whom I entered into conversation informed me that it was the 

 third brood they had brought off this season. — E. Fortune (5, Gros- 

 venor Terrace, East Parade, Harrogate). 



Records of Rare Birds. — On Aug. 15th, at Frensham Pond, in 

 Surrey, I was fortunate enough to see half a dozen Black Terns 

 hawking for insects over the water. They were mostly adults, and 

 very tame. There was one Common Tern with them, and a few 

 Black-headed Gulls. At the same place I watched a Spotted Fly- 

 catcher treating a moth much as a cat behaves with a mouse. It flew 

 with it to the top of a notice-board, and beat it or its own mandibles 

 several times on the wood, while the moth's wings whirred audibly. 

 It then released it, but caught it again as it made for some furze. It 

 then let it go once more and recaptured it, after which the bird flew 

 away with it out of sight. On Sept. 5th, at Cley, Norfolk, I saw a 

 Black-tailed Godwit, which passed quite close to me, the wind being 

 north-west at the time, after a gale during the night. On Sept. 20th 

 I had two good views of a Barred Warbler, once as it flew past me, 



Zool. 4th ser. vol. XIV., October, 1910. 2 h 



