22G NOKTII AMKKICAN IHRDS. 



The woiiiU'itul sntiacitv disijlawd bv this Wiirhh'i' in avoidinu: the disa- 

 ijreeabh' alternative ot" eitlier havinij tn altandon its own nest or nt' rearini: 

 the yonnu of the intrusive ('«»\v lilaekliird. wlien one of these ei,'«^s is dro})]»ed 

 in lier nest, was lirsl notieed hv Mr. Nuttall. The e^i; of the i»ara.site. heinu 

 too Liri^e for ejeitnii'nt, is ingeniously inearei'rated in the bottom of the nest, 

 and a new lininu huilt over it. Oeeasionallv, either hv aeeident or desii^n, 

 the intrusive eu;^ has heen fraetureil. Mr. Nuttall states that where the 

 parasitie eyi; is laid after her own. the Sunnner Velh»w-l)ird aets faithfully 

 the i>art of a foster-])arent. This, however, is not aeeordinu; to my olt.serva- 

 tions. In several instances I have known the Summer Vellifw-Uird utterly 

 refuse to act the part of a foster-]»arent, and, rather than do so, sacrifice her 

 own ejij^s. So far as I know, this \Varl»ler will never sit upon or hatch out 

 the e«j;g of the Cowliird, under any circumstances. Some ])owerful instinct, 

 honlerinn clost'lv uimn reason, seems to teach these intelligent Warhlers the 

 character of the intrudi-r, and thev sacrifice their own emjjs rather than rear 

 the parasite. In this dihMuma they wili always, so far as I know, incarcer- 

 ate their own eiigs with the ('owhird's and reconstruct the nest ai>ove them. 

 In one instance the same pair of Vellow-Uirds twice, in the same nest, cov- 

 ered u]) alien ej^ujs in this maimer, luiildini;, in fact, three nests one above 

 the other, between the walls of which had l»een successively included two 

 egjis of the C'owbird. This three-storied nest measured seven inches in 

 len^^th, and was built almost exclusively of raw cotton. The coverin<^ of the 

 imprisoned eijiis was about two thirds of an inch thick. In both instances 

 the Cowbinl's e^us had beiMi broken, a])]»arently by desiLiu. 



So far as I am aware this Warbler raises but one brood in Massachusetts 

 in a season. In IVnn.sylvania it is said to raise two, and even three. The 

 e«r«js are usually five and occasionally si.\ in nundier. 



This Warbler is eonspieuous in its devotion to its vounj'", evincini; a stronu 

 attachment and an an.xiety in regard even to an un«)ccuj)ied nest, and be- 

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

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

 gems and manieuvres. 



The sonu: of the Summer Yellow- liird is sim])le but ]ileasint:, and is easily 

 reco«4nized when o»ieo known, thou'di liable to be confounded with that of the 

 ]\Iaryland YeUow-Thniat, and also said to resemble the song of several other 

 Warblers. 



In confinement they usually })ecome very tame, confidin«j, and reconciled 

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

 fintrer, and to catcii Hies in a room. 



Their etyrs vary in leni]:th from .01 to .70 of an inch, and in breadth from 

 .49 to .02. They have a ground-color of a light green. Their dots and 

 blotches yary i^reatlv in numb(q-. size, and nsanner of distribution. Their 

 colors are light purjjle, ilarker ]>urj)lish-brown, and other shades of brown 

 and lilac. 



