BIRD NOTES 103 



(with thunder) working in an opposite direction : 

 the sky being lighted up below the storm-cloud; 

 for this brighter spot they were evidently heading. 

 They appeared lumps of bedraggled feathers, and 

 scarcely able to ply their wings. At the rate of 

 60 or 70 per minute, I computed some 2000 birds 

 must have passed in half an hour. 



A very similar incident occurred on Ormesby 

 Broad the August previous, when I and a friend 

 were fishing. A terrific thunderstorm, and probably 

 the heaviest downpour of rain I was ever caught in, 

 had, as it were, drawn into its midst a confused 

 cloud of Swifts, Swallows, and Martins ; these were 

 struggling towards the horizon, where there was an 

 apparent break in the leaden skies. Whether they 

 ever reached it I am unable to say. It is probable 

 that in such unexpected storms many of these 

 delicate birds perish. Their soaked plumage at 

 anyrate reduces them to sore straits. 



On one occasion I saw a gunner bring down a 

 Swift. Opening its mouth, I saw in its gullet a mass 

 quite a teaspoonful of a species of small dipterous 

 insect. The favourite item in its bill of fare is the 

 St. Mark's Fly (Bibio marci). 



On 13th May the arrival of the first Swifts is 



