280 
Correspondence. 
that, the Missel Thrush and Fieldfare failed to rear the two young ones. 
They lived for eleven days and could not have had better parents, whose 
one fault seemed to be over feeding . The young ones grew rapidly, 
but on the eleventh day one wa^ pioke 1 up dnad twenty yards from tha 
nest, while the other was dead in the cartridge box in which the nest 
had been built. They appeared to be well nourished and showed no signs 
of a violent death. I have been forced to the conclusion that wh'^n birds 
nest under the somewhat unnatural conditions of an aviarj% 'hey lose 
their brains. Grey and Yellow Wagtails and Larks; Gold, Bull, Green, 
and Bramble Finches; Siskins; King Ouzels; Chaffinches, et'"., all nest, 
but almost invariably desert or let their young die during the second 
week . 
The Silky Cowbird ha^i b 'en a 'great nuisance this year with h^'r 
Cuckoo-likc habits of dropping on? of hiT large eggs in nests of Gold 
Finches, Siskins, Hedge Sparrows, etc. FRANK JOTINSOy. 
Hove, 4-vii-'14. 
[It would be most interesting if Major Johnson would describe 
the eggs of the Silky Cowbird and state if they varied to any extent 
in th.' respective nests. — Ed.]. 
AN INTERESTING OBSERVATION 
Sir. — On the evening of July 3()th, while walking across some 
fields, my attention was attraided by a loud and continuous screeching, 
and on looking up I noticed thousands of Swifts circling above iny liead 
at all altitudes from fifty or sixty feet, to some hundreds of feet up. 
The wind was light and easterly in direction, and the time <3 p.m. 
The Swifts extended in a northerly dircdion as far as the eve could 
reach, and were a|)par('ntly moving in a South-easterly di/'cc(ion (■)- 
wards Eastbourne, which is abuut twelve miles distant from Ihe place 
they were seen at . 
After gazing in wimdvr at such a, vast concourse of birds, I 
wended my way westwards and rapidly passed out of the belt of birds, 
and saw no more until retracing my route homewards and to the jiorth, 
when at 7 o'clock I f;aw about twenty or thirty circling very high up, 
but rapidly disappearing towards Eastbourne to the south-easL ["'inally 
at 7-5 p.m. I saw the last tv,-o Swifts that evening, and thc^'- 
too rapidlj- disappeared in the same direction. 
An interesting feature was that I never remember being so 
bothered by small flies while ri<ling my motor-bicycle. There were 
myriads of them and they nearly formed a cloud in the air. 
Car. this be the summer migration of Swifts If so it is earlier 
than usual. L. LOVELL-KEAYS. 
AN INTERESTING NEST. 
Sir. — I am sending you photos of a nest of the Black-headed 
Weaver (Hijphaiiloni's mrlanorcpfiaius'), which may prove of some little 
interest. 
This nest was woven over a Canarj-\s ncsf, while incubation was 
going on, but the Canaries continued their duties uniriti'i-ruptiMlly . 
