226 NORTH AMERICAN IHRDS. 



The woiuU'vt'ul sagacity displiiyi'il by this Warhkn- in avoiding the disa- 

 ureoahk! ahrinativo of I'ithcr iiavinu; to ahandon its own lu'st or of vcarinij; 

 tlic yinnij; of the intnisivo Cow r)iai'l\l)iiil, wht'n oni' of liii'si' I'gij.s is drui)]ied 

 in hor nest, was liisl notiied liy Mr. Niittall. Tiit; ogg ol' tiie parasite, heing 

 too hirge lor ejeetnient, is ingeniously incareerati'd in the hottoni of the nest, 

 and a new lining liuilt over il. Oceasionally, either hy aeeident or design, 

 the intrusive egg has been fractured. Mr. Xuttall states that where the 

 ])arasitie egg is laid after her own. tlie Summer Vellow-liird acts faithfully 

 the])artofa foster-parent. This, however, is not aeeording to my oiwrva- 

 tions. lu several instances I have known the Summer Vellow-l>ird utterly 

 refu.se to act the part of a foster-jiarent, and, rather than do so, saeritice iier 

 own eggs. So far as I know, this \\ arhler will never it upon or hatch out 

 the egg of the Cowliird, under any circumstances. Some ])owerful instinct, 

 bordering closely upon reason, seems to teach the.se intelligent Warblers the 

 character of the iutnuler, and they sacritii'e their own eggs rather than rear 

 the ]iarasite. In this dilennna they will always, so far as 1 know, iiu-arcer- 

 ate their own eggs with the ('o\\bird's and reconstiuct the ni'st alnive them. 

 In oni? instance the sanu' jtair of VeUow-Uirds twice, in the .same nest, cov- 

 ered u]) alien eggs in tiiis manner, liuildiug, in fact, three nests one above 

 the other, between the walls of which iiad been successively included two 

 eggs of the ("owbird. Tiiis ihree-storied nest measured seven inches in 

 lengtJi, and was built almost exclusively of raw cotton. The covering of the 

 imju'isniied eggs was about two thirds of an inch thick. In both instances 

 the Cowliird's eggs had been broken, a]i]iarently iiy design. 



So far as I am aware this \Vari>ler rai.ses but one brood in IMassachusetts 

 in a season. In rennsylvania it is said to raise ^wo, and even three. The 

 eggs are usually live and (H'casionally si.\ in numlier. 



This Warbler is conspicuous in its devotion to its yiaiiig, evincing a strong 

 attachment ami an anxiety in regard even to an unoccupied nest, and be- 

 traying the site by this solicitude. They will also resort to various exi>edi- 

 ents to draw one away from their nest, by feigned lameness and other strata- 

 gems aiul mano'uvres. 



The song of the Sumnu'r Ycllow-Iiird is simple but |ilensiiig, and is easily 

 '•ecogni/ed when once known, though liable to be ciuifoiuidi'd with that of the 

 Maryland ^'ellow-Tllroat, and also said (o resemble the son,g of seveial other 

 Warblers, 



In conliuement they usually beconu' very tauu>, fMuiliding, and reconciled 

 to their imprisoinueiit, and have been known to perch on an outstretched 

 linger, and to catch Hies in a room. 



Their eggs vary in length from .01 to .7" of an inch, and in Ipivadth from 

 .4'.) to .oL'. They have a ground-color of a light green. Their dots and 

 bhttches vary greatly in nundicr, si/e. and maimer of distribution. Their 

 colors are light purple, ilarki'r pui'iilish-brnwu, and other shades of brown 

 and lilac. 



