GRINNELLS SMALL-BILLED WATERTHRUSH 491 



is one of tlie most common bush-frequenting birds throughout the 

 entire fur countries, extending north even beyond the tree limit." 



Its migration route seems to be mainly east of the Rocky Mountains, 

 as it is apparently only accidental in California and farther south 

 along the Pacific coast of Central America. 



Nesting. — Baird, Brewer, and Ridgway (1874) give us the following 

 short account of what were probably the first reported nests of 

 Grinnell's waterthrush : "Among other memoranda given me by the 

 late Mr. Kennicott was one furnished him by Mr. Lockhart, to the 

 effect that, at Yukon River, June 21, 1859, he had shot a female Water 

 Thrush as she flew from her nest. This contained five eggs, and was 

 concealed under a small pile of drift, close to the river, but under large 

 willow-trees. This was not lined with down. At the same locality 

 another nest with six eggs was also obtained. This also was on the 

 ground at the foot of some willows near the water. It was made of 

 moss, and lined with very fine grass." 



Henry C. Killingstad writes to me from Mountain Village, Alaska : 

 "These birds nest wherever there is brush or tree growth. The pres- 

 ence of water is a foregone conclusion here where everything is wet. 

 I found one nest on June 13, 1943, under the upthrust end of a piece 

 of driftwood 20 feet from the Yukon, Earlier in the same month I 

 saw several birds carrying nesting material along a spring-fed trickle 

 through the alders north of the village. This little stream is not more 

 than 2 feet across, but where it cuts into the tangled alders it makes 

 many tunnels and labyrinths through which the birds can be found 

 feeding day and night." 



Richard C. Harlow has sent me the data for a nest that he found 

 north of Belvedere, Alberta, on June 17, 1926 ; it was well-hidden in 

 the overhanging upturned roots of a spruce tree, a foot above stagnant 

 water, on the edge of a wet, swampy portion of the woods ; it was made 

 of leaves, weed stalks, mosses, and fern stalks. 



Eggs. — Grinnell's waterthrush lays from 4 to 6 eggs to a set. These 

 are apparently indistinguishable from those of the northern water- 

 thrush. The measurements of 21 eggs average 19. 1 by 14.4 millimeters ; 

 the eggs showing the four extremes measure 20.7 by 15.3, 19.8 by 15.4, 

 and 16.0 by 12.7 millimeters (Harris) . 



Voice. — Although he never made a record of it, Aretas A. Saunders 

 tells me that, from his limited experience with it, he believes that the 

 song of Grinnell's waterthrush is "distinctly different from that of 

 the northern waterthrush." But published accounts indicate that 

 there is a decided similarity in the songs of the two subspecies, which 

 one would naturally expect to find. And H. C. Killingstad adds : "At 

 Mountain Village, this bird does not act as it does in the States. Its 

 loud, clear, and pleasing song is heard from bush and tree tops, one 



