184 MOLOTHRUS PECORTH, COW-BIRD. 



circumstances, devoid of conscious design, lacking recognized prevision ; 

 totally inadequate to the requirements of the first special emergency. 

 What bird, possessed of only such a faculty as tbis, could buikl a two- 

 story nest to get rid of an objectionable deposit in the original single- 

 story fabric ? It argues as intelligent a design as was ever indicated in 

 the erection of a building by a human being. No question of inherited 

 tendency enters here ; and if it did, the issue would be only set back a 

 step no nearer determination, for there must have been an original 

 double nest, the result of an original idea. Nor is this wonderful fore- 

 thought very rarely exhibited; considering what proportion the double 

 nests discovered bear to the ordinary ones brought to our notice, among 

 the millions annually constructed, we can easily believe that the inge- 

 nious device is in fact a frequent resort of the birds plagued by the 

 Cow-bunting. And how can we sufncieutly admire the perseverance 

 and energy of a bird which, having once safely shut up the terrible egg 

 in her cellar, and then having found another one violating her premises, 

 fortJticith built a third story f She deserved better of fate than that her 

 house should at last be despoiled by a naturalist. This was a Summer 

 Yellowbird, to whom the price of passing thus into history must have 

 seemed hard. 



The Cow-bird's foster-parents are numerous ; the list of those so deter- 

 mined is already large, and when completed will probably comprise 

 pretty much all of the species nesting within the Cow-bird's breeding 

 range, from the size of a Thrush down to that of the Guatcatcher. It 

 is unnecessary to recite the long list ; Iwill mention, however, the Wood 

 Thrush, Yellow-breasted Chat, and Towhee Bunting, as showing that 

 the foster-birds are not always smaller than the Cow-bird itself. The 

 Summer Yellowbird, the Maryland Yellow-throat, and the Eed-eyed 

 Vireo, are among those most persistently victimized. On the prairies- 

 of the west, where the Cow birds are very numerous, and breeding birds 

 restricted in number of species if not of individuals, I had almost said 

 that in a majority of the nests taken in June will be found a Cow- 

 bird's Qgg. 



In the nature of the case it is impossible to say what is the normal 

 number of eggs usually deposited each season by a single bird — that is 

 if more than one be laid, as is probable. We can only presume, quite 

 reasonably, that the laying is of four or five eggs, as usual among the 

 allied species. Neither do we know whether the same individual ever 

 deposits more than one egg in the same nest — at least I am not aware 

 of observations on this score, and they would be necessarily very difii- 

 cult, if not impossible, to make. Finding several Cow-bird's eggs in a 

 nest, as frequently happens, proves nothing to this effect, for the same 

 nest might easily enough be used by different Cow-birds in succession. 

 It is rare to find more ihau two of the alien eggs together ; I have found 

 three in a Towhee-Bunting's nest, and even Jive have been discovered 

 in the same nest. Singularly enough, these unusual numbers were in 

 the nest of the same species. Thus ]\Ir. T. ]\Iartiu Trippe, in his inter- 

 esting article on the Cow-bird (Am. Nat. iii, 291), cites a remarkable 

 case : "I never heard of more than two instances where there were more 

 than two eggs of the Cow-bird in a single nest. Prof Baird and Dr. 

 Brewer once found three eggs in the nest of a Black-and-white Creeper, 

 and I once had the good fortune to discover a nest of the same bird 

 containing Jive eggs of the parasite, together with three of her own. In 

 the latter case incubation had begun, and all of the eggs contained em- 

 bryos." We may consider this pair of Creepers relieved, on the whole, 

 by Mr. Trippe's visit — the mother-bird rescued from drowning in the in- 



