LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 217 
Nesting—Mr. W. Elmer Ekblaw contributes the following ex- 
cellent account of the nesting habits of the dovekie: 
The nesting sites are determined probably by several factors, perhaps of 
equal significance. These sites are always along cliffs with rather steep talus 
slopes, of rather large fragments, among which the birds can find entrances, 
and cavities well enough within shelter to be safe from winds and weather 
and predatory animals. In suitable talus slopes its nests extend from near the 
high tide water mark to the top of the slope, in every possible place. Because 
of the slow disintegration of the rocks, as compared with the breaking off of 
the fragments from the cliffs, the talus slopes are piles of coarse rocks with 
cavities, passages, crevices, and tunnels everywhere among them. In these 
cavities and passages at various distances from the outside, according to the 
convenience and safety of the place, the nests are placed. Frequently a mat 
of grass grows over the surface of the rocks, but since it is only a superficial 
mat, and as long as openings are left for the ingress of the birds, this does not 
detract in the least from the desirability of the site. Along Foulke Fjord, 
on the cliffs south of Cape Alexander, and near Sonntag Bay I have found 
thousands nesting on what was apparently only a grass slope with an occa- 
sional projecting rock, but examination revealed the fact that it was only a 
concealed talus slope after all. Where the breaking down of the cliff above, 
or where there is considerable rolling of the surface rocks, the grass does not 
form, though upon the margins of the talus tongues, and in a semicircle about 
their terminations when they do not reach the sea the grass mat encroaches. 
In a few cases the grass mat has so deeply covered the talus that the auklets 
have abandoned it, because they could not enter. Not only in the talus piles 
does the dovekie nest, but also in crevices—almost without exception in hori- 
zontal crevices—it makes its home as well; but this only when talus slopes 
near at hand have nests too, for this little bird is most socially inclined, nest- 
ing, feeding, swimming, flying, and migrating in great gregarious flocks. 
It builds no nest. Its one egg, or rarely two, is laid on a rock or shelf in a 
passageway or cavity, usually in a niche along, or at the end of, a passageway. 
This rock, after many generations of auks have nested there, is covered with 
moore or less damp dung, upon which the egg or eggs are laid. Several nests 
may be very close together, or considerable interval may occur between a nest 
and its neighbor. The entrance to a nest is usually marked by a white patch 
on the rock, where more than the usual amount of dung is deposited, for when- 
ever one of the old birds alights at the entrance, he, or she, almost invariably 
defecates. The earliest eggs are laid in the last week of June, but it is during 
the first week of July that laying is at its height, at Etah. In the last week in 
June the Eskimo women begin gathering the eggs, but they are not so plentiful 
as they become a week later. Each female lays one egg and this is the usual 
number. Rarely two eggs are laid, and in four cases of this that I saw the 
eggs were slightly smaller than the normal egg. 
Eggs—tThe single egg is “ ovate” or pointed ovate in shape. Its 
shell is smooth but without luster. All the eggs that I have seen are 
plain bluish white and immaculate; I have never seen any of the 
alleged spotted eggs of this species. The measurements of 44 eggs, 
in various collections, average 48.2 by 33 millimeters; the eggs show- 
ing the four extremes measure 51 by 34, 49 by 35.5, 45 by 33, and 46 
by 32 millimeters. 
