246 THE GANNET 



Another way to estimate these Gannets is by taking as 

 a standard of comparison the piebald, or two-year-old birds, 

 whose mottled backs render them very conspicuous, 

 especially when viewed from above. During the three days 

 that I was at the Bass in 1905 there may have been on an 

 average fifty of these piebald Gannets. After looking round 

 and making a mental computation, I held that it was fair 

 to say that for every piebald Gannet there were a hundred 

 white ones, that is, adults. This would give 5000 adult 

 Gannets, but Mr. Laidlaw, of the lighthouse, says that every 

 evening many more adults come in from fishing. Let us 

 put this nightly accession at 750, and if we hazard a guess 

 that 750 more belonging to the Bass remain at sea, the 

 majority of which would be male birds or non-breeders, we 

 get a net result of 6500 Gannets forming the Bass Rock 

 community. 



A third way of forming an estimate is by calculating from 

 the number of young ones which used to be killed, and here 

 we are on safer ground. These Bass bird-harvests are of 

 very old date, and fortunately we have returns for so 

 far back as the seventeenth century.* We learn from 

 them that in 1674, 1118 young Gannets were gathered; 

 in 1675, 1060; in 1676, 1150, and in 1677, 985. From that 



* See p. 215. 



