26 
GULLS AND TERNS 
with subterminal band of dusky; rest of 
tail, under parts, forehead, and eyelids 
white. Length: 13.50-15.00, wing 11.25, 
bill 1.30, tarsus 1.60. 
Distribution. — Interior of North 
America, breeding’ from Iowa north into 
Canada; migrating south to Peru. 
Nest. — On broken-down rushes in shal¬ 
low water, made largely of grasses and 
rushes. Eggs: usually 3. 
In the northern plains and prairie country Franklin gulls are of 
the greatest economic importance, the immense flocks living mainly 
on grasshoppers and other destructive insects. At times a white 
horde will descend upon a ploughed field, a band of them following 
at the heels of the ploughman, while long white lines cover the 
mellow furrows. Recognizing the ploughman as a friend, the birds 
only get out of his way to let him pass, waiting for him to turn up 
a fresh supply of food for them. They walk in the furrows or 
hover low over the ground, diving quickly to pick up any squirm¬ 
ing morsel, either insect or rodent, that has been unearthed by the 
plow. One often sees flocks of fifty to five hundred catching grass¬ 
hoppers on the wing, wheeling, diving, and rising, till at a distance 
the white flock suggests a wild flurry of snowflakes. When the 
meal is over the birds disband, to scatter out among the sloughs, 
drift on lazy wings over the lakes, or float idly on the surface of the 
water. Vernon Bailey. 
60. Lams Philadelphia ( Ord ). Bonaparte Gull. 
Adults in summer. — Bill and head black ; mantle delicate pearl gray; 
three outer quills chiefly white, outer 
web of the first, and terminal portion of 
all, black ; tail and under parts white; 
feet orange red. Adults in winter : head 
white, tinged with gray behind and with 
a dusky spot on ear coverts ; feet pale 
flesh color. Young: top of head, back, 
and spot on ear coverts dusky ; sides of 
head, neck, and under parts white, in¬ 
cluding tail coverts and base of tail; 
band across end of tail blackish, feathers tipped with white. Length : 12- 
14, wing 10.25, hill 1.20. 
Distribution. — North America, breeding far northward; south to western 
Mexico. 
Mr. Henshaw states that the Bonaparte gull is not uncommon in 
San Diego Bay in December, though he thinks it winters mainly to 
the southward. 
Mr. Loomis has seen the gulls at Monterey during their migrations 
in November and May. He says that “although white-throated 
birds with the tail-band were in the majority, and pied-headed ones 
Fig. 44. Wing of Franklin Gull. 
