290 
BIRDS OF NEW MEXICO 
apparently non-breeding birds were seen at Lake Burford, May 24 and 30 and June 
5-7, 14, and 17, 1918 (Wetmore).] In fall, one was taken September 27, 1904, 
at Lake Burford (Bailey); several large gulls, probably this species, were seen 
September 15, 1905, at a large pond near El Rito (Hollister); and one at Thirteen- 
mile Lake, Chaves County, October 26, 1896 (Barber). 
In winter, on the Carlsbad Bird Reserve, 300 were estimated January 1, 1915 
[and 500 December, 1916 (Willett)]* 
A few were noted in migration along the Rio Grande near Fort Thorn in the early 
days by Henry, and a few gulls of undetermined species have been noted in recent 
years passing up and down the Rio Grande in spring and fall (Leopold). One was 
taken April 20, 1901, at Albuquerque (Birtwcll); and one May, 1903, at Mangas 
Springs (Metcalf).—W. W. Cooke. 
Nest. —In colonies, often on islands, on the ground, generally scantily lined with 
grass. Eggs: 2 to 3, clay-color, buffy or whitish, spotted with chocolate. 
Food. —Dead fish, frogs, salamanders, crawfish, and small mollusks; insects and 
their larvae, especially locusts and grasshoppers, together with mice and other small 
rodents. In times of “mouse plagues” they do effective work in destroying the pests, 
and near towns do important work as scavengers. When McMillan Lake was 
drained in September, 1916, they did away with the fish left stranded by the receding 
water. 
General Habits— The beautiful snowy and pearly robed gulls and 
terns are so familiar that we forget to ask why they are so differently 
clad from other birds that we know. A suggestive explanation has 
been offered by Abbott Thayer. As he points out, they have an 
“obliteratively disposed combination of soft water and cloud-like 
pearly gray, with bright shadow-absorbing white,” which, whether 
flying or swimming, gives them “the greatest average inconspicuous¬ 
ness.” On the other hand, their black wing markings shown in flight 
and displayed by holding up the wings for a moment on alighting, as 
in the case with plovers and sandpipers, make good recognition marks. 
As Mr. Seton points out, “all birds with ample wings and habits of 
displaying them, bear on them distinctive markings” (1897, p. 396), 
including not only the gulls and plovers, but hawks and owls, in con¬ 
trast to birds like the hummingbirds, which move their wings too 
rapidly to be seen and so lack wing patterns. 
The Ring-billed Gull, which formerly was one of the most widely 
distributed of gulls, Mr. Bent explains, “could never survive the egging 
depredations which the Herring Gull has withstood successfully.” It 
“yields readily to persecution, is easily driven away from its breeding 
grounds, and seems to prefer to breed in remote unsettled regions, far 
from the haunts of man,” being now “mainly restricted to the interior, 
in the lakes of the prairies and plains of the Northern States and 
Canada” (1921, p. 132). 
Highly gregarious, both on its breeding grounds and in its winter 
resorts, it congregates in large flocks of its own kind, associating also 
with a variety of others. 
