34 
BULLETIN OF THE NUT TALL 
NOTES ON THE BREEDING OF THE BLACK TERN (HYDRO- 
CHELIDON LARIFORMIS) IN MINNESOTA. 
BY T. S. ROBERTS. 
The Black Tern is the most abundant representative of its family 
in this State, making its appearance in the vicinity of Minneapolis 
about the middle of May. Stragglers remain until the first week 
in September, but the majority leave during the latter part of 
August. For a short time after their arrival they are to be seen 
flying leisurely around the larger lakes ; but as the nesting-season 
approaches they select some prairie slough or marshy lake, and 
there spend the greater part of their time until the young are able 
to fly. Late in May or early in J une the nest is built and the eggs 
are laid, or the eggs are deposited without any nest, as the case 
may be. Dr. Cones mentions (Birds of the Northwest, 1874) meet- 
ing with a colony breeding along the Red River, and states that 
there w^ere no nests whatever, the eggs being placed on beds of 
decaying reeds. Such is their habit under some circumstances, but 
only two instances of the kind have come under my notice as yet. 
Once, I found three eggs laid directly on the mud on an abandoned, 
broken-down muskrat house in the midst of a large slough. The 
same day I found another set of two* eggs on a bed formed by the 
bending over of the tops of some tall dead grass. They were thus 
raised more than a foot above the water, which w'as of considerable 
depth. There was no indication of a nest, the eggs being held in 
place by resting among the coarse grass. A very interesting and 
valuable note on this subject occurs in a short article by Dr. P. L. 
Hatch, published in the Bulletin of the Minnesota Academy of 
Natural Sciences for 1876. It is an extract from a letter written 
by Mr. E. W. Nelson of Chicago, and although the observations 
were not made in this State, I will introduce them here : “ I have 
seen the eggs of Sterna plumhea deposited on masses of floating 
weeds in several instances, but only for the third brood, the bird 
having previously built two nests and deposited the eggs in both, 
which had been removed by myself to ascertain how many they 
would lay. The result was almost invariably as follows : first nest, 
three eggs ; second nest, two eggs ; and the third, one egg. In 
