374 THE GANNET 



occasionally be seen with nest material in their beaks, but I have 

 no proof that the nest-building instinct is ever developed in them 

 beyond this stage. 



The one dirty yellow-stained egg is incubated by each of the pair 

 in turn for about six weeks. 1 Sometimes the sitting bird declines to 

 leave the eggs. On one occasion I saw one of a pair alight, proceed 

 to the sitting bird, and try to push it bodily off the nest, at the same 

 time seizing and wringing its head. The victim made no effort to 

 resist, but simply sat fast. After a while the newcomer desisted, 

 began to cosset the injured head, and presently the incident closed 

 with the usual lively interchange of marks of affection, one standing, 

 the other still seated. 



The gannet's method of incubation merits special attention. It 

 was first noted by Conrad Gesner in his Historic^ Animalium (1555). 

 He states that he learned from an " erudite Scotchman " that the 

 solan-geese "lay their eggs on rocks and cover them with one foot 

 during the process of incubation." The statement, subject to the 

 alteration of one foot to both feet, has been verified by E. T. Booth 

 from observations of birds in captivity, 2 and by Mr. J. M. Campbell, 

 the head-keeper of the Bass Rock light-station. 3 The bird places 

 over the egg the web of one foot and then the web of the other, and 

 lowers the body. The egg is not always wholly covered. The discolora- 

 tion of the egg originally chalky white is held to be due to this 

 habit, the underside of the webs being wet and dirty. The same 

 method of incubation has been observed in the case of Sula capensis 4 

 (S. Africa) and Sula serrator (Australia). 5 



The earliest date of hatching recorded is 10th May, by E. T. Booth, 

 but June is the most usual month. The latest record I have is 

 12th August. The young gannet is born naked, blind, and of a slaty 

 hue, a most unprepossessing little creature ; but in a few days it begins 



1 See " Classified Notes." * Rough Notes, vol. iii. 



3 The Scotsman, 28th June 1910 ; and in litt. 4 Ibis, 1904, p. 84 (W. L. Sclater). 



6 Victorian Naturalist, 1908-9, p. 18. 



