59 
Nesting. Nest of dead rushes and debris in wet marshes adjoining prairie lakes and 
doughs. 
Distribution. The interior, from Manitoba to Alberta. Not known to breed north 
of the prairie sections and not recorded from British Columbia. 
This is a characteristic Gull of the prairies. Nesting in large colonies 
in the marshy sloughs and lakes, these Gulls appear in clouds of thousands of 
individuals and follow the heavy gang ploughs in flocks that almost hide 
the driver and team from view. 
They settle on the freshly turned black earth, packing into their eager 
crops the grubs, worms, and larvae that are scurrying to new shelter after 
the upheaval. One surface quickly exhausted, they rise to air again, beat 
over their companions still busily at work, whirl once or twice about the 
ploughman so closely that he might cut them down with his whip, and settle 
on freshly turned clods again, to repeat the operation over and over. Thus 
it goes from daylight to dark and the destruction carried into the insect 
ranks on these fields preparing for cultivation is enormous and well appre- 
ciated by the husbandman. Later in the season when the green, half- 
grown grain waves in the wind, there is a constant procession from the 
breeding sloughs out over the farmland. Beating across the soft green 
fields, a flock of a hundred or more will pause, hover a moment, and then 
drop into them, sinking from sight — one, a few, or many at a time, in a 
little spot that makes the onlooker wonder that so many can find shelter 
and concealment in so small a space; but the sea of grain closes over them 
so that no sign is visible of the eager activity below. Presently a black 
wing is raised, a white body flashes in the sun; others follow, and for a 
moment there is a white outboiling that presently resolves itself into the 
flock, wing-borne to again circle away over the many-acred field and repeat 
the performance. At times a number of such aggregations can be seen at 
once over a single field. The attraction is generally grasshoppers and the 
number of these insects that a few hundred Gulls can devour on a long 
summer day, and day by day throughout the season, is an important factor 
in insect control. 
Again, in the evening, they may mount the upper air over or near lake 
shores and, high up, gleaming like jewels in the last rays of the setting sun 
while the ground below perhaps is lost in blue evening shadows, they weave 
intricate aerial patterns in pursuit of the “lake flies” that blow in smoke- 
like clouds about them. 
In the autumn, they often unite with flocks of Bonaparte’s Gull, form- 
ing incredible numbers, and drive up and down over the harvest fields, 
rising on whistling wings to pass over obstructions and again descending 
to barely a man’s height from the ground as they gather the insects from the 
air. What species forms their special pursuit at this time has not been 
definitely ascertained, but undoubtedly the great majority of their tiny 
prey are better placed in the crops of hordes of Gulls than peaceably per- 
mitted to prepare for next season’s crops. 
Economic Status. On the whole, the western farmer probably has 
no more efficient friend than this little Gull of tireless wing, and the indigna- 
tion of the community should be experienced by those who disturb their 
nesting or interfere with their security. In many localities, a swamp 
where these Gulls breed is worth far more as insect insurance to the sur- 
