176 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



Nesting. — I have never succeeded in finding its breeding grounds 

 and must quote from what scanty accounts of its nesting habits have 

 been published. Mr. Roderick MacFarlane (1891) writes: 



Thirty-seven nests arc recorded as having been talsen, with eggs in them, be- 

 tween 10th June and 10th July, in the wooded country in the neighborhood of 

 Fort Anderson and on Lower Anderson River. They were all built on trees at 

 various heights (from 4 to 15 and even 20 feet) from the ground, and, with 

 one exception, which was composed of down and velvety leaves held together 

 by some stringy turf, they were made of small sticks and twigs lined with 

 hay and mosses, etc. The parents always fly about in close proximity to the 

 nest, and scream vehemently when explorers, in the Interests of science, are 

 obliged to deprive them of their eggs or young, and not infrequently shoot one 

 of them. They seldom lay more than three eggs. 



The following account is published by Baird, Brewer, and Ridg- 

 way (1884) : 



Mr. Kennicott found this gull nesting in the neighborhood of Fort Yukon, 

 and describes the nest as being of about the size of that of Zenaidura carol- 

 inensis; but the cavity is rather deeper. It veas placed on the side branch of 

 a green spruce, several feet from the trunk, and about 20 feet from the ground, 

 near a lake. Mr. Kennicott saw several nests near this one, all alike and in 

 similar positions, except that some were not over 10 feet from the ground, and 

 were on smaller trees ; but all were on spruce trees. One nest which he exam- 

 ined contained three young birds of a dirty yellowish color, thickly spotted with 

 dark brown. He saw between 25 and 50 gulls about that breeding place, but he 

 found only a few of their nests. These birds were said by the Indians always to 

 breed in similar situations. 



This species apparently bred formerly as far south as Michigan 

 and Wisconsin, in the region of the Great Lakes. Mr. W. H. Col- 

 lins (1880) was told by hunters living at St. Clair Flats that Bona- 

 parte's gulls bred "in Baltimore Bay and the North Channel, and 

 that they lay their eggs on old logs with no signs of a nest." Kum- 

 lien and Hollister (1903) write: 



In 1880 a few were said to breed on Chambers Island, Green Bay, and we 

 saw on some small islands in Big Bay de Noquet, Michigan, a number of nests 

 like pigeons' nests on the flat branches of low coniferous trees that without 

 question had been used by these birds. 



Eggs. — The Bonaparte's gull lays from two to four eggs, ordina- 

 rily three, frequently only two, and rarely four. The eggs somewhat 

 resemble those of the Franklin's gull, but are considerably smaller. 

 In shape they are ovate, pointed ovate, or pointed elongate ovate. 

 The ground color varies from " buffy citrine " or " Dresden brown " 

 to " dark olive buff " or " deep olive buff." They are more or less 

 evenly spotted or irregularly blotched, rarely scrawled, with various 

 shades of brown, " brownish olive," and " brownish drab," too numer- 

 ous and variable to be definitely named. The measurements of eggs, 

 in various collections, average 49.5 by 34.9 millimeters; the eggs 



