276 THE SCOTTISH NATURALIST 



and able to fly. On 16th August the breeding place was 

 found to be deserted, and many old birds were feeding their 

 young on the shore. A. R. G. 



Bird-marking and Mortality. 



It seems desirable to refute as completely as possible 

 the suggestion unfortunately made by thoughtless persons 

 in 1 910, that a connection was to be found between the 

 mortality described and the marking of the young birds of 

 this colony with the rings of the Aberdeen University Bird- 

 Migration Inquiry. The matter was even reported to the 

 Royal Society for the Protection of Birds, but Mr Lewis 

 Bonhote, corresponding with me on behalf of the Society, 

 expressed himself fully satisfied as to the groundlessness 

 of the accusation. I should like to make good the following 

 points : 



(1) No reasonable suggestion has been made as to how 



ringing could be the cause of death without leaving 

 visible signs of injury. 



(2) Similar conditions of high mortality have been reported 



to us from colonies where no ringing was in progress. 



(3) Ringing was carried out at Forvie in 1909, 191 1, and 



1913, and elsewhere in various seasons, without any 

 such mortality occurring. 



(4) In the seasons 1910 and 1912 ringed birds formed no 



more than a due proportion of the dead, considering 

 the large number that had been marked. Unfortun- 

 ately, we have not a sufficiently reliable estimate of 

 the total size of the colony to state actual percentages. 

 But in 1910 Mr Ramsay stated that the great majority 

 of the dead seen by him were unmarked, while in 

 191 2 Dr Galloway collected the following figures : 



The total number of dead young found on 21st July 

 was 125, of which only 4 bore rings; 105 young Terns 

 were marked that season, and of these only 1 1 were 

 discovered among the hundreds of dead examined 

 on various dates. The latter figures suggest a death- 

 rate of only 10 per cent., while the general death-rate 



