28 



The Canadian Field-Naturalist 



[Vol. XXXVI 



were found in the marsh. 



These Grebes did not breed in colonies, but 

 each area of marsh contained its quota of nasts. 

 and, generally, they were thiity or foity yards 

 apart. As only a small port^lon of the lake was 

 visited, a correct census of the birds could not 

 be taken, but it was estimated that sev nty-five 

 pairs were breeding. 



Two years later, June 22nd, 1918, the numb?r 

 had been greatly reduced. During the autumnof 

 the previous year there had been a considerable 

 mortality through a parasitic disease which may 

 explain their relative scarcity in 1918. 

 Pied-billed Grebe: Podilymbus podiceps. 

 These were less common and much less in 

 evidence than the last. Sitting birds would steal 

 away from their nests without being seen and 

 did not show the solicitude for their eggs that 

 marked the behaviour of the larger species. A 

 nest containing seven eggs and another with one 

 egg were found on May 15th, 1916. The nests 

 were smaller than the Holboell's, but built of 

 the same material in similar situations. In both 

 nests the eggs were completely covered. Another 

 nest, containing eight eggs, was found on June 

 8th, 1916, and the covering of wet weeds was 

 removed, leaving the eggs exposed. Upon my 

 return to the nest twenty minutes later, it was 

 discovered that the bird had returned in the inter- 

 val and had covered the eggs again. 



Two nests, similar to the last, found on June 

 22nd, 1918, contained three and five eggs respec- 

 tively and the birds were seen gliding through 

 the rushes with only head and neck above the 

 water. These were the only occasions on which 

 I was able to obtain a glimpse of the birds as 

 they left their nests. 



Loon: Gavia immer. A pair seen on June 8th, 

 1916, were swimming back and forth in front of a 

 marshy point in one of the lagoons at the north 

 end of the lake. Their nest was quite close but 

 impossible to reach without the aid of a boat. 

 Two other pairs were seen at a distance in the 

 open water. On June 22nd, 1918, two downy 

 young were in the same lagoon. They dived 

 through the matted weeds on the surface, appeared 

 for a moment farther on, and then vanished in 

 the thick tules while the parents called to them 

 from the open water fifty yards distant. 



Black Tern: Hydrochelidon surinamensis. 

 Finding a breeding colony of Black Terns was 

 a decided surprise. I had no record of their 

 breeding in the Okanagan Valley and had known 

 them only as scarce migrants. When I was 

 approaching the marsh on May 18th a band of 

 thirty or more were seen flying over the lagoon, 

 and, as I neared the water's edge, they flew to- 



wards me, circling over my head with cries of 

 c.„ii.i. ii. iLorough search of the marsh was made 

 for nests, but nest-building had not started. 

 Three weeks later, on June 8th, the birds had 

 started laying and a number of nests contained 

 cne or two eggs. Most of these were on a float- 

 ing rraes of dead rushes which had drifted into 

 the lagoon and lodged against the tules. In a 

 few nests a scant lining raised the eggs above 

 this floating mass of debris, but the greater num- 

 ber consisted of a simple arrangement of dead 

 rushes, barely sufficient to keep their contents 

 from rolling out. In the play of light and shadow 

 diffused through the tall encircling tules, nests, 

 eggs and the immediate surroundings blended so 

 harmoniously that many nests would have escaped 

 observation had it not been for the excited cries 

 of the parents as they wheeled low over the 

 nesting sites. Several nests, and these were 

 conspicuous, departed from the usual in being 

 made of fine reddish roots of some water-plant, 

 probably brought to the surface by a muskrat. 

 One bird was seen brooding eggs on a small piece 

 of floating debris in one of the deeper portions of 

 the lagoon and she remained there quietly while 

 I watched at close range — close enough to see 

 the maroon-colored gape and the gentle brown eye. 



While I was wading through the tules, the 

 Terns flew around me on all sides, often within 

 arm's length, and were quite devoid of fear in 

 their parental solicitude. Often three or four 

 birds, following each other closely, would fly 

 straight towards me until within a few feet, 

 when they would rise slightly and pass over my 

 head, to circle back and repeat the manoeuvre. 

 While the birds were frequently all in the air at 

 the same time, they turned and wheeled or dropped 

 out of sight behind the tules so quickly it was 

 impossible to count them. Ten nests were found, 

 but it is thought the colony numbered twenty 

 pairs at least. The breeding ground was restrict- 

 ed to an area about two hundred yards square at 

 the north end of the lake. 



When I visited the marsh next, on June 22nd, 

 1918, the Terns were in the same place and the 

 colony was larger. The floating masses of rushes were 

 again in position and afforded the chief nesting 

 site. With the increase in the number of birds, 

 the nests had been built closer together and in 

 several places four or five were in sight at one 

 time. Twelve nests were examined, the majority 

 of which held three eggs, the maximum number. 



Cinnamon Teal: Querquedula cyanoptera. 

 Three drakes and two ducks were seen swimming 

 close to shore on May 18th, 1916, and on June 

 8th, 1916, two drakes and one duck were seen 

 together. It is probable that they were breeding 



