n6 



the preceding season ; in like manner I expect that 

 their third and fourth year birds will be discovered 

 to be of the same age. 



The graceful manner in which the Gannet 

 takes it prey, steadying itself for a moment in the 

 air, and then darting headlong beneath the waves, 

 must be seen to be thoroughly understood. 



The amount of fish that these birds consume is 

 something enormous. It has been estimated that 

 the Bass Gannets number about 50,000, and as 

 each bird will readily devour ten herrings in a day, 

 it can be easily calculated that the market value of 

 the fish required for one day's consumption by -this 

 colony alone would be considerably over 1,000. 



The specimens in the case, representing the 

 birds at one and two years old, were obtained at the 

 Bass Rock during August, 1874. 



See "Kough Notes," Vol. III., Plates 29, 30 and 31. 



GEEAT BLACK-BACKED GULL. 



(IMMATURE). 



Case 155. 



The adult specimens represented as attacking 

 the Highland lamb are only introduced to illustrate 

 the destructive habits of this rapacious bird. 



A weakly ewe is no sooner discovered than 

 she is set upon, and after being either forced into 

 some crevice among the rocks, or slowly butchered 

 by thrusts from their powerful bills, the lamb next 

 falls an easy victim. 



This is by no means an uncommon occurrence, 

 still this interesting Gull receives the benefit of the 

 Act for the preservation of sea birds. 



The specimens in the immature stages, shewing 

 the third or fourth, and also the second year's 

 plumages, were shot in the Highlands in 1877. 



See " Kough Notes/' Vol. III., Plate 37. 



