324 THE GANNET 



and suppose a census taken at every Gannetry on the 1st 

 of May, 1910, which would be before any of the eggs would 

 have had time to hatch. It seems simpler to take the 

 month of May than to suppose a census done in August, 

 and to let it include the young ones, of which a very large 

 percentage appears to die a natural death during the first 

 twelve months — that is, if they have not already been 

 killed for eating by human beings. 



ESTIMATED NUMBER OF GANNETS (Sula hassano) IN THE 

 NORTHERN HEMISPHERE. 



England — 



Lundy Island . . . . . . . . . . — 



Wales — 



Grassholm Island . . . . . . . . 400 



Ireland — 



Bull Rock, CO. Cork 500 



SkelligRock 16,000 



— 16,500 



Scotland — 



Ailsa Craig . . . . . . . . . . 6,500 



St. Kilda— 



Borrera 16,000 



Stack Lii 8,000 



Stack Armin 6,000 



30,000 



