162 BULLETIN 107, UNITED STATES NATIONAL MUSEUM. 
‘CEPPHUS MANDTI (Mandt). a 
MANDT’S GUILLEMOT, 
HABITS. 
The northern “sea pigeon” is essentially a bird of the Arctic 
Ocean, though it also breeds in portions of Hudson Bay and the 
North Atlantic, where it can find practically Arctic conditions in 
summer. It has been seen as far north as 84°-in summer, and 
apparently pushes northwards in the spring as fast and as far as the 
leads open in the ice. 
Mr. W. Elmer Ekblaw writes to me as follows: 
If any water bird in the Smith Sound region merits the adjective ubiquitous, 
the guillemot certainly does. Throughout the entire extent of the northwest 
Greenland coast and along the shores of Hllesmereland this active, pigeon- 
like bird is found throughout the open season; in the open water of the sound 
it finds sustenance even in the dark of winter. There is no fjord so deep that 
the guillemot does not enter into its head; there is no promontory so stormy 
or so steep that the guillemot does not frequent it. As there is hardly a rock 
ledge on land that does not form the home or hunting ground of the snow bunt- 
ing so along the coast there is no ledge or cliff that does not afford a home and 
nesting site to one or many guillemots. 
This species has been said to breed in northern Labrador, and 
perhaps it may do so in the vicinity of Cape Chidley, but all the birds 
that we collected as far north as Nain proved to be Cepphus grylle. 
Mr. Lucien M. Turner did not find it breeding in Hudson Strait and 
saw only occasional pairs or solitary individuals. According to Rev. 
C. W. G. Eifrig (1905), the Canadian Neptune Expedition found 
this species “at Cape Fullerton, where they are common summer 
and winter, as also throughout Hudson Bay and northward; some 
were seen at North Devon.” 
Nesting—Mr. Ekblaw describes the nesting habits of Mandt’s 
guillemot quite fully, as follows: 
The birds begin mating about the 1st of June; the first eggs are laid about the 
10th or 15th of June, though some pairs begin more than a month later. The 
mating act takes place on the edge of the ice along the leads of the open water, 
or on the small pans of ice floating about. The mating antics suggest those of 
domestic ducks. It is not so gregarious in nesting time as are the kittiwakes, 
the murres. or the fulmars; single pairs not infrequently are the sole occupants 
of a ledge or cliff, but generally they have considerable company of their own 
species. It does not avoid the proximity of other birds, nor does it seek their 
company. It nests in crevices and joint fissures in the rocks rather than on 
ledges, and this choice of nesting place determines the assemblage of its own 
kind and other species with which it may be found. If the crevices be numerous, 
and near good feeding grounds, many guillemots may be associated; if ledges 
suitable to the nesting of other species are found about the crevices, then usu- 
ally the company is mixed; or if the right kind of talus slope be near, the 
dovekie may nest beside or above it. Because it thus frequents the crevices and 
deep niches in the rocks rather than the ledges, it is not so readily detected at 
