THE GREAT BLACK-BACKED GULL. 177 



on its domains, it keeps over him at a safe distance, not sailing so much as 

 moving to either side with continued flappings. To secure the fishes on 

 which it more usually preys, it sweeps downwards with velocity, and as it 

 glides over the spot, picks up its prey with its bill. If the fish be small, 

 the Gull swallows it on wing, but if large, it either alights on the water, or 

 flies to the nearest shore to devour it. 



Although a comparatively silent bird for three-fourths of the year, the 

 Great Black-backed Gull becomes very noisy at the approach of the breed- 

 ing season, and continues so until the young are well fledged, after which it 

 resumes its silence. Its common notes, when it is interrupted or surprised, 

 sound like cack, cack, cack. While courting, they are softer and more 

 lengthened, and resemble the syllables cawah, which are often repeated as it 

 sails in circles or otherwise, within view of its mate or its place of abode. 



This species walks well, moving firmly and with an air of importance. 

 On the water it swims lightly but slowly, and may soon be overtaken by a 

 boat. It has no power of diving, although at times, when searching for 

 food along the shores, it will enter the water on seeing a crab or a lobster, to 

 seize it, in which it at times succeeds. I saw one at Labrador plunge after 

 a large crab in about two feet of water, when, after a tug, it hauled it ashore, 

 where it devoured it in my sight. I watched its movements with a glass, 

 and could easily observe how it tore the crab to pieces, swallowed its body, 

 leaving the shell and the claws, after which it flew off to its young and dis- 

 gorged before them. 



It is extremely voracious, and devours all sorts of food excepting vege- 

 tables, even the most putrid carrion, but prefers fresh fish, young birds, or 

 small quadrupeds, whenever they can be procured. It sucks the eggs of 

 every bird it can find, thus destroying great numbers of them, as well as the 

 parents, if weak or helpless. I have frequently seen these Gulls attack a 

 flock of young Ducks while swimming beside their mother, when the latter, 

 if small, would have to take to wing, and the former would all dive, but 

 were often caught on rising to the surface, unless they happened to be among 

 rushes. The Eider Duck is the only one of the tribe that risks her life, on 

 such occasions, to save that of her young. She will frequently rise from the 

 water, as her brood disappear beneath, and keep the Gull at bay, or harass it 

 until her little ones are safe under some shelving rocks, when she flies off in 

 another direction, leaving the enemy to digest his disappointment. But 

 while the poor Duck is sitting on her eggs in any open situation, the 

 marauder assails her, and forces her off, when he sucks the eggs in her very- 

 sight. Young Grouse are also the prey of this Gull, which chases them 

 over the moss-covered rocks, and devours them before their parents. It 

 follows the shoals of fishes for hours at a time, and usually with great success. 



Vol.VII. 26 



