210 THE SKUAS 



would have been unendurable, and, as it was, they made the experi- 

 ment far from agreeable. The attacks were delivered by birds that 

 had almost fledged young. 1 If the nesting-area is intruded upon after 

 the young have left it, the parents, if there, will still attack, though 

 not so viciously, and probably from force of habit. 



The attacks of the Arctic-skua are of the same nature, except 

 that the species prefers to make them from the flank or rear rather 

 than from the front. Not that the great-skua always makes a frontal 

 attack ; it appears, however, to do so more frequently than the smaller 

 species, but why is not clear, unless it be that its greater strength 

 makes it feel superior to indirect methods. Both as to this and 

 as to the occasions on which the birds make no attack, it is at 

 present impossible to generalise with any assurance, owing to the 

 varying behaviour of individual birds a factor not infrequently 

 underestimated. 



According to Howard Saunders, Naumann, and others, 2 the Arctic- 

 skua strikes with the wing-tips. If this is correct, it constitutes a note- 

 worthy difference between the two species. It seems, however, hardly 

 credible, and is not supported by detail sufficient to show that the 

 observers saw as well as felt the blow delivered. It is quite possible 

 that a blow with a bird's foot, if not seen, might be mistaken for a 

 blow from the wing-tip. 



In making their attacks upon intruders, the great and Arctic-skuas 

 are comparatively silent birds ; they do not end their charges with the 

 discordant shrieks indulged in by Gulls and Terns. The final assault, 

 or swish over the head, is indeed usually made without any uttered 

 sound. 3 Before this, or afterwards, the great-skua may be heard utter- 

 ing its croaking " ag ! ag /" or "ak! akf" and the Arctic the mewing 

 note already referred to. The latter has also a querulous note syllabled 

 as " mee, mee" which has been heard from it when its young were being 



1 Bird Watching, p. 123. 



2 Manual of British Birds, 2nd ed., p. 692 ; Vogel Mitteleuropas, xi. 327 ; Evans and Buckley 

 Fauna of the Shetlands, p. 196 ; Naumann even makes the species strike with the beak. 



' Of. E. Selous, Bird Watching, p. 121. 



