Peron Roserts, Nesting Habits of Franklin’s Guill. 273 
Preston on ‘ The Breeding of Franklin’s Gull in Minnesota,’ pub- 
lished in 1886 in the ‘ Ornithologist and Oologist’ (Vol. II, p. 54). 
Preston’s notes were based upon observations made during a visit 
to the Heron Lake colony several years previous to the first visit 
made by the writer. The material for the present article is the 
accumulation of three trips in three different years to the same 
general locality. On the last visit the Gulls were studied at 
intervals for a period of fifteen days, under most favorable and 
varied conditions, and a series of photographs embracing about 
one hundred negatives was secured, a selection from which is 
presented herewith. My companion on this latter expedition 
was Mr. Leslie O. Dart, and I wish here to acknowledge a by 
no means inconsiderable indebtedness to him for the successful 
issue of our work, especially in the photographic line. To his 
able coéperation is due very largely the beauty of the best of 
the illustrations accompanying this paper. 
About the time of the final loosening of the ice in mid-April 
the vanguard of the Rosy Gulls arrives, and by the time the sur- 
face is clear they are coursing back and forth in great numbers over 
the broad expanse of open water that presents itself at this season 
of the year. The transients soon pass on or scatter to neighbor- 
ing sloughs, and the Heron Lake Colony, proprietors by right of 
no one knows how many years of occupancy, select with much 
noisy consultation the location for the year. The mating contests 
over and settled, the busy, turbulent throng then begin the work 
of nest-building, which consumes the first few days of May, so 
that by the middle of that month the laying of the eggs has 
begun, and in three or four days thereafter the sets are complete, 
and the tedious task of incubation has begun. These dates are 
sometimes anticipated a little, while on the other hand a late 
season may cause delay, so that the depositing of the eggs may 
occur as early as the end of April or be postponed until the latter 
part of May. The Rosy Gull, like others of its family, nests 
strictly in colonies, and even on a lake as large as Heron Lake, 
all the individuals there resident congregate at one place and 
build their nests close together. But, unlike most birds breeding 
in colonies, the site chosen is rarely the same on any two succes- 
Sive seasons. Just why this should be so is not evident. It 
