58 
BULLETIN 
U. S. DEPARTMENT OF AGRICULTURE. 
eggs have been reported. It breeds south to the lakes on the upper 
Pelly River in Yukon (Pike) and to Atlin in northern British Colum- 
bia (Anderson) ; these five places seem to be the only sure records of 
actual nesting. Although the species has been reported as nesting 
at various places south to southern British Columbia, Alberta, Mani- 
toba, southern Keewatin, and even to North Dakota, Minnesota, 
Wisconsin, and Michigan, it is very suggestive that it is not known 
Bonaparte's gull (Larus Philadelphia). 
to nest on any of the large lakes in southern Mackenzie, where it 
would certainly breed if it did at these much more southern locali- 
ties. The probabilities are that Bonaparte's gull is an arctic- and sub- 
arctic-breeding bird which finds its most congenial home on the Arctic 
lakes and rivers at the farthest north it can find the evergreens on 
which it places its nest. 
During summer, nonbreeding individuals of the species occur com- 
moniv on the coast of southeastern Alaska (Swarth) and not rarely 
