46 MEMOIRS OF THE NUTTALL ORNITHOLOGICAL CLUB 



SO it is probable that it arrives on our coast at least as early as May. William 

 Eagle-Clarke^ says that the date of arrival of the Wilson's Petrel at the breeding- 

 grounds in the South Orkney Islands is a very constant one, the nth or 12th of 

 November. How much time is needed for this seven-thousand-mile migration 

 from the Essex County coast to the antipodes I cannot say. 



[lis] Sula leucogastra (Bodd). Booby.— Erroneous record. 



38 [117] Sula bassana (Linn.). 



Gannet. 



Common transient visitor. March 26 to June 7; August 28 to December 21. 



The Gannet is always well worth watching in his fishing operations. In the 

 original Memoir I described these in detail and by comparison with the masts of 

 schooners judged that the plunge was made from a height of from thirty to 

 one hundred feet. Eagle-Clarke^ was enabled irom the top of the tower of the 

 Eddystone Light to gauge the height from which these birds dived with a degree 

 of accuracy not usually attainable. He witnessed many thousands of dives, but 

 in no case did the drops exceed a height of from 130 to 140 feet. The height 

 of the dive is so directly proportionate to the depth of the fish, that herring fisher- 

 men are guided by watching the birds and set their nets accordingly. 



On October 11, 1908, I saw a flock ofif Ipswich Beach of about seventy-five 

 of these birds plunging with a feeble splash from a height of only two or three 

 feet. Their prey was evidently near the surface. On October 16, 1910, I 

 counted 230 of these splendid birds off the beach ; about two-thirds were in adult 

 plumage. At times in the fall the proportion of immature birds is much larger. 



I stated in the Memoir that the bare skin at the base of the bill is yellow. 

 This is an error; it is blue black. 



39 [119] Phalacrocorax carbo (Linn.). 

 Cormorant; Common Cormorant. 



Uncommon transient and winter visitor. November 13 to April. 



Even the severe winter of 1917-18 did not drive these birds from their fishing- 

 grounds at the Salvages off Rockport. They were seen there by Mr. Charles R. 



1 Eagle-Clarke, W. " Birds of the South Orkney Islands." Ibis, ser. 8, vol. 6, p. 145, 

 1906. 



2 Eagle-Clarke, W. Studies in Bird Migration, vol. i, p. 302-303, 1918. 



