-^ 



oioqi 



MARCH, 1879. 



No. 8. 



Coues on the Nest and Eggs of 



the Water Thrush (Siurus 



naevius).* 



[From '• Birds of the Colorado Valley."] 



fUNE is the lieiglit of the breeding sea- \ 

 son with this bird. During this 

 month, egg-laden nests hiive been 

 found so fur apart as are Maine and Ahis- 

 ka — early in the month in the New Eng- 

 land locality just mentioned, and later on 

 the Yukon River. Doubtle.ss only one 

 brood is reared in the higher latitudes to 

 which the birds resort ; the case may also 

 be the same in other localities, and proba- 

 bly is so, considering how soon — by the 

 fore part of August — these birds reappear 

 in places where they are not known to breed, 

 as in Illinois and Jamaica. In the few in- 

 stances which have come to the knowledge 

 of naturalists, the Water Thrush's nest was 

 built on the ground or its equivalent. The 

 Alaskan nests to which I have alluded were 

 placed by the river bank, at the foot r)f wil- 

 low-bushes, one of them beneath a small 

 pile of drift-wood, and contained four to six 

 eggs. These and other Arctic nests, as 

 preserved in the Smithsonian Institution, 

 are about four inches across by two-thirds 

 as much in depth ; they are composed chief- 

 ly of moss, compactly matted and mixed 

 with little sticks and straws, one of them 

 having also a large amount of circularly- 

 woven fibrous material in a state of disin- 

 tegration. A nest found in Maine by Prof. 

 A. E. Verrill, and described with particu- 

 larity by Dr. Brewer, was built in an ex- 

 cavation in the side of a decayed log, which 



*Siiitrux novcboracenain in former publications. 

 Dr. Coues gives preference to "Aquatic Accentor'' 

 as the English term. 



overarched the structure somewhat as the 

 domed portion of the nest of the Golden- 

 crowned Thrush covers the main part of 

 the structure. It was a beautiful fabi'ic, 

 built chiefly of green Ili/pnum mosses, with 

 which a few withered leaves and plant-stems 

 were mixed, having a compact iiuier por- 

 tion or lining of the fruit-stems of the same 

 Hypnum, and showing a number of slen- 

 der black rootlets intertwined around the 

 outer circumference. It was flatter and 

 shallower than the nests I have seen, being 

 four and a half inches across, but only one 

 and a half high, with a cavity half an inch 

 less in depth. "This nest contained five 

 eggs, the brilliant white grtjiuul of which, 

 with their delicately shaded spots of red- 

 dish brown, contrasted with tiie bright gi-eeii 

 of the mossy exterior, and set off to advaii- 

 tage by the conspicuous and uiii(|ue lining, 

 produce a very beautiful efl'ect." 



The numerous eggs I have examined — 

 I all, however, after they had been emptied 

 I oftheir contents-measure from three- fourths 

 to four-fifths of an inch in length by a little 

 more or less than two-thirds of an inch in 

 breadth — more exactly, two selected spec- 

 imens give respectively the measurements 

 0.75x0.58 and 0.82x0.60. The ground- 

 color of the shell is brilliant crystal-white ; 

 this is marked all over, but in most cases 

 more thickly at and around the larger end 

 : than elsewhere, with small spots of reddish, 

 of quite dark brown, and of lilac or laven- 

 der — sometimes all the spots being dots 

 ' and mere points ; sometimes many of them 

 beinir larirer, and more or less confiuent to 

 enwreathe the greater end of the egg. Oc- 

 casionally the other end, or evQU some con- 

 siderable part of the egg, is nearly free from 

 markings, but the shell, as a rule, is pretty 

 thoroughly speckled. 



