OCT. 1906. 
HERRING GULL AND CASPIAN TERN. 
119 
conspicuously unlike the almost equally large Royal Tern 
(S. maxima), the Caspian Tern appears to breed in isolated pairs 
instead of large colonies, its nest being usually far removed from 
that of any other bird, and consisting merely of a shallow de- 
pression scooped in the sand, with little if any lining, though a 
few grass, or sedge, blades or other vegetable substances are 
sometimes added." 
Both these authors mention the addition of grass, of which 
we saw none ; and Ridgeway has found it a solitary breeder, while 
we. found it in a colony of probably fifteen hundred birds, and its 
nests frequently less than a yard from its nearest neighbors. 
Baird, Brewer and Ridgeway say : "The nests consisted of 
slight hollows in the sand, with a few sticks gathered round." 
The sticks could hardly be useful, and seem to indicate a remnant 
of a nest building instinct ; or they might even be considered deco- 
rative. The subject should be investigated farther. 
Variation is less marked in the tern eggs than in those of the 
gulls. Three specimens selected from a small number measure, 
in millimeters, 59x46, 60^2x41^ and 64x42^. The ground color 
varies from cream to chalky white. The markings from fine dots, 
through spotted to blotched. One specimen noted is materially 
different in markings on one side than upon the other. 
The laying of the Herring Gull at Gravel Island appears to 
• be later than in many parts of North America, and its average 
number of eggs appears to be less. Hornaday writes of a pair 
nesting in the New York Zoological Park: "During the whole 
nesting period, lasting from April 1 to May 15, he either bluffed 
or fought to a standstill everything that came within ten feet of 
that nest." Several authors, without specifying locality, mention 
May as the laying month, while Audubon, writing of these gulls 
at the Bay of Funday, says : "Some individuals begin to lay about 
the 19th of May or a few days earlier, while others have not 
finished the process until the middle of June." 
There is an unanimity among authors in assigning "three as 
the proper number of eggs, yet in 1905 I noted that about half 
the nests had but two, and this year, out of five sets taken, four of 
them with large embryos, but a single set was of this larger num- 
ber. Coues, writing of the gulls in Labrador, says : "The eggs, 
in all instances that came under my observation, were three in 
