Breeding-grounds of the Rosy Gull. 135 



taking a regular bath. It dipped its head under, while 

 sitting deep in the ice-cold lake, and, throwing the water 

 over its back, moved its wings quickly below the surface, 

 holding them somewhat apart from the body. Then it 

 lifted itself almost clear and threw itself forcibly head down- 

 wards into the water. Once a Rosy Gull flew over the 

 surface of the lake with a cry of " carvac-wa " and took up 

 water with its beak on the wing, as Swallows do, but subse- 

 quently it settled on the surface for some two or three 

 seconds without folding its wings, which were elevated over 

 the back, and drank after the usual fashion. 



From June the 3rd onwards Rhodostethia became scarce on 

 the river and was dispersed over the delta, though the snow 

 was still deep in the bushy portions and the ice had only 

 melted for a distance of a fathom or two from the banks. 

 1 did not think that the birds had begun to lay their eggs, as 

 the female which was killed on May the 31st had the yolks 

 in the ovaries not more than 8 mm. in diameter ; but several 

 clutches were brought to me — all somewhat incubated — on 

 June the 13th, the very day on which the ice on the Kolyma 

 at last broke up. The last four clutches, taken by myself 

 on June the 26th, were so much incubated that the embryos 

 were covered with down, and would have been hatched in 

 a very few days. At this time of the month the bushes 

 of Alnus and the Salices became perceptibly green, and 

 mosquitos appeared in considerable numbers, but the middle 

 of the lake not immediately connected with the river was 

 still covered with ice. 



I found the Rosy Gull nesting in little colonies of from 

 two or three to ten or fifteen pairs, in company with the 

 common Black-capped Tern of the delta, which, however, in 

 nearly every case exceeds it in numbers *. 



* This Tern is of the Sterna Jliiviatilis type, hut has the whole hill 

 red to the tip, and the breast and belly (not the vent) nearly as grey as 

 the back. Tail with outer webs of two outer pairs of feathers grey; outer 

 web of first primary blackish ; dark shaft-stripes on inner webs of primaries 

 not wider than their outer web. So far as I can judge, without books or 

 other materials, it is not Sterna paradisea. 



