LIFE HISTORIES OF ]SrORTH AMEKICAN GULLS AND TEKNS. 133 



Courtship. — According to Audubon (IS-tO) mating takes place be- 

 fore the birds reach their breeding grounds. He says : 



When spriug has fairly commenced, our common gulls assemble in parties of 

 hundreds, and alight on mud flats or sandy beaches, in out eastern estuaries 

 and bays. For awhile they regularly resort to these places, which to the gulls 

 are what the scratching or tooting grounds are to the pinnated grouse. The 

 male gulls, however, although somewhat pugnacious, and not very inveterate in 

 their quarrels, making up by clamor for the deliciency of prowess in their 

 tournameuts. The males bow to the females with swollen throats, and walk 

 round them with many odd gesticulations. As soon as the birds are paired they 

 give up their animosities, and for the rest of the season live together on the 

 best terms. After a few weeks speut in these preparatory pleasures, the flocks 

 take to wing, and betake themselves to their breeding places. 



Nesting. — ]My first experience with the nesting habits of the ring- 

 billed gull was on " the enchanted isles " of Stump Lake, North 

 Dakota, three small islands in a western arm of the lake, now in- 

 cluded in the Stump Lake Reservation. On May 31, 1901, and again 

 on June 15, 1901, I visited these interesting islands, with Mr. Her- 

 bert K. Job (1898) who had previously described and named them. 

 Two of the islands contained breeding colonies of ring-billed gulls, 

 consisting of about 100 pairs each; one held a colony of about 75 

 pairs of double-crested cormorants; and one a large colony of com- 

 mon terns. All of them offered suitable nesting sites for various 

 species of ducks, of which we found no less than 40 nests on June 15. 

 Certainlj^ the bird population of these little islands warranted Mr. 

 Job's title. The gulls' nests were placed upon the ground along the 

 upper edges of the beaches and among the rocks and bowlders which 

 were scattered all over the islands. They were made of dried grasses 

 and weeds, sometimes of small sticks; were lined with finer grasses 

 and were often decorated with feathers. On May 31 all the nests 

 contained eggs, many of which had been incubated a week or 10 

 days; on June 15 not over one quarter of the eggs had hatched and 

 many of them still held incomplete sets. 



One of the most interesting gull colonies I have ever found was 

 on a small island in Big Stick Lake, Saskatchewan, on June 14, 

 1906, where large numbers of this and the preceding species were 

 l)reeding, together with a number of other water birds. I have 

 already described this colony more fully in my account of the nest- 

 ing habits of the California gull. The nests of the ring-billed gulls 

 were on the higher portions of the island, somewhat apart from those 

 of the larger species, but mingled with them to some extent. The 

 nests were made of dead weeds, straws, rubbish, and feathers; they 

 measured from 10 to 12 inches in diameter, and the inner cavity 

 was about 9 inches across and 2 inches deep. Most of the nests were 

 in open situations, but some were partially hidden among the rocks 



