GULLS 
219 
The amount of fish they consume is relatively unimportant, as it is 
usually only very abundant small species occurring in great schools that 
attract their attention. They are not patient fishers like Herons, content 
to stalk their prey and take one fish at a time, but want them in abundance 
so that they can gulp them in quantities. They search low tidal shores 
for crabs and other shell-fish, showing considerable ingenuity in breaking 
the hard shells and extracting the contents, in many cases carrying them 
into the air and dropping them on the hard ground and rocks to shatter 
them. The food supply from these sources is economically insignificant. 
Gulls annually dispose of vast quantities of garbage and offal in the harbours 
and waterways and hence are beneficial scavengers. On the British Colum- 
bia coast they frequent the salmon rivers and gorge themselves on the 
spent and dying salmon. (The western salmon, unlike those of the east, 
after completing their mission of procreation die by thousands in the 
streams.) Undoubtedly at times some species destroy salmon eggs, but, 
as most of these are laid at the heads of streams rather than at the mouths 
where the greatest number of gulls congregate, their opportunity for serious 
damage is not great, except under exceptional circumstances or on short 
streams where the spawning grounds are within easy reach of the coast. 
Another charge against them is their egg-stealing proclivities when in 
the vicinity of rookeries of other species such as murres and cormorants, 
nor do they confine themselves to eggs alone, helpless unguarded young 
birds being equally welcome to them. It is apparent that when gulls 
attack economically valuable species, objection may be taken to too great 
numbers of them, but their normal activities in this direction can as a rule 
be disregarded. 
Gulls also frequent agricultural land for insect food. Indeed, some 
species are characteristic of the broad inland prairies. At times gulls 
have been instrumental in stopping small mammal and grasshopper plagues 
and the Mormons of Utah have erected a monument to gulls that appeared 
at an opportune moment and destroyed the crickets that were ravaging 
the fields and producing famine. Gulls must be considered, therefore, as 
beneficial on the whole, and should be protected, although they do some- 
times destroy eggs, young birds, and fish, and occasionally thieve from 
the fishermen. 
42. Glaucous Gull, burgomaster, le goeland bourgmestre. Larus hyper- 
boreus. L, 28. One of the largest of the gulls. Of Herring Gull type of coloration, but 
mantle very pale and wing tips white (Figure 318). In the adult the mantle is only tinged 
vath grey and younger specimens are nearly white, being only clouded with brownish or 
brownish cream. Birds of the year are slightly barred with ashy brown. 
Figure 318 
Wing of Glaucous Gull; scale, about £. 
Iceland Gull the same but smaller. 
