LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 29 
again out in the open water. And numerous chicks just from the egg dove 
hastily out of sight and escaped in the thick grass. So close together were the 
nests that often three or four sets could be taken without moving the boat. 
Most of the eggs were so far advanced in incubation that they were not taken, 
e put by selecting the cleanest sets and testing them by putting them in the water 
we secured about 75 sets, about 60 of which were saved in fair condition. 
The sets ranged from 1 to 5 (mostly 3) while those found at the other end 
of the lake were from 6 to 10. The nests exhibited surprising regularity and 
not a little ability on the part of the architects. The rafts all consisted of a 
number of stems of the long marsh grass, laid in the form of a triangle, with 
the ends crossed to keep them from floating apart. A second triangle was 
Jaid across the first so as to make a six, or often a five, pointed star, between 
the points of which several stems of grass were left growing acting as a 
mooring, and so preventing the nest from floating away. In the center an 
open space was left, in and over which was built the nest itself, which was a 
mass of mud and moss brought up from the bottom (apparently). A hollow 
in the center which contained the eggs usually also contained an inch of water, 
as the nests were almost submerged. 
Mr. Robert B. Rockwell (1910) says of the nesting habits of the 
eared grebe in Colorado: 
The eared grebes’ nests were easily distinguishable by the flimsy and ap- 
parently careless manner in which they were constructed, being very slight, 
straggling platforms of large, rank, green dock stems, cat-tails stalks, rushes, 
weeds, and grass, usually floating in comparatively open water, or in very 
sparse growths of cat-tails, with no apparent attempt at concealment. The 
nests were very flat, the nest cavity often being actually below water level, 
and the eggs in most cases being wet. How these eggs with damp shells retained 
enough heat either from the parent or from the sun’s rays to hatch them, is a 
problem which I have been unable to solve. And as a matter of fact quite a 
perceptible per cent of old nests examined contained addled eggs. 
On June 12, 1905, while exploring an extensive breeding colony of 
Franklin’s gulls in a marshy lake, near Crane Lake, Saskatchewan, 
I found a large number of eared grebes scattered about among the 
gulls’ nests and well concealed in the thick growth of bulrushes 
(Scirpus lacustris) with which that end of the lake was thickly over- 
grown. The nests were the usual small floating masses of rotten 
reeds, water mosses and other vegetable rubbish, with which some of 
the eggs were wholly or partially covered; the nests measured from 
12 to 14 inches in diameter externally and 5 to 6 inches internally ; the 
eggs were not more than 2 to 8 inches above the water, usually less. 
Dr. T. S. Roberts (1900) relates a similar experience: 
This colony of Franklin’s gulls has as associates and intimate neighbors 
many coots, pied-billed grebes, black terns, a few Forster’s terns, and, most 
notable of all, because so unexpected in this place, a colony of American eared 
grebes (Colymbus nigricollis californicus). There were a hundred or more 
of these latter birds and they had established themselves in the very midst of 
the gull colony. Their nests, which were the very poorest structures that 
could be called by such a name, were disposed in two or three principal groups, 
