56 
Field Marks. Except the even red coloration of the bill, which is not an absolutely 
reliable guide, there is no field mark that can be described by which this species can be 
recognized with certainty. As in eastern Canada it is a sea coast species, it should be 
recorded on eyesight evidence only where it is known to occur commonly. 
Nesting. Depression in sandy beaches. 
Distribution. Nearly cosmopolitan, but of eastern and Arctic distribution in Canada 
and rarely if ever seen in the Great Lakes region. It is notable from having perhaps the 
greatest migration range of any species of bird. Though found in summer north close to 
the pole, it winters as far south as the Antarctic continent. 
The remarks made under the heading of the Common Tern will very 
well apply here, bearing in mind that this species is regularly only of extreme 
eastern and Arctic distribution. 
Economic Status. The small size of the fry it takes and the known 
abundance of such fish in the sea, renders this species as harmless as any 
of the other Terns. 
77. Black Tern. FR.—LA STERNE NOIRE. Hydrocheledon nigra. L, 10. (Forking 
of tail, 0-8)! The smallest of our Common Terns, dark slate-grey deepening to dull black 
on head, neck, and underparts. 
Distinctions. The above diagnosis is sufficient to separate summer adults. Winter 
and immature birds have a dirty white face, throat, neck ring, and underparts and the 
grey above is suffused with more or less brownish. It is, however, always considerably 
darker than corresponding plumages of other species. This fact and its small size should 
be sufficient to differentiate it at all times. 
Field Marks. Size and coloration make this species easy to recognize in life. 
Nesting. On slight elevations such as old muskrat houses or floating debris in wet 
marshes, nest of vegetable matter. 
Distribution. The American Black Tern is a bird of the interior, breeding from the 
Great Lakes region westward. 
SUBSPECIES. The Black Tern occurs in both Europe and America in allied sub- 
specific forms of which the European is the type. The American Black Tern H.n. sur- 
inamensis is the only subspecies with which we are concerned. 
This is a bird of the inland marshes. It is rarely seen on the larger 
bodies of water, but within its regular range no extensive expanse of 
watery marsh is without it. Its general habits are much like those of the 
other Terns. 
Economic Status. The insect content of this bird’s food is probably 
larger than that of the other Terns. In the south it is known to consume 
the larve of the cotton-boll weevil and probably retains some insectivorous 
habits with us. Therefore, we can venture to state that it is probably 
actively beneficial. At any rate the fish it takes, if any, are mud-inhabiting 
forms of small economic importance. 
Order—Tubinares. Tube-nosed Swimmers. 
General Description. ‘Tireless fliers of the deep sea, of various sizes from the large 
Albatross to the small Petrel. Usually dull and evenly coloured birds. 
toy Nostrils are encased in tubes laid on top of the bill proper (Figure 10, 
p. 19). 
Field Marks. General flight habits and coloration. Familiarity with the various 
species is necessary to recognize members of the order. 
Nesting. On ground or in burrows in out-of-the-way localities, often on rocky islets 
far out at sea to which they find their way in some mysterious manner that we cannot as 
yet explain. 
1See footnote, p. 54. 
