CONTOPUS BOREALIS, OLIVE-SIDED FLYCATCHER. 243 



"So Strong is the attachment of birds to the nests of their own con- 

 struction, that the parental instinct is often lost sight of. Proofs could 

 be cited to sustain this assertion. One, however, will suflice. Two 

 years ago, in Atlantic Count)', New Jersey, I came across a nest of the 

 Robin, which, on account of its curious arrangement, I desired to pos- 

 sess. Unable to wait until the unfledged brood had taken their depart- 

 ure, I conceived the plan of removing them to another nest of the same 

 species, not so neatly constructed or so tastefully arranged. But, as I 

 had anticipated, the mother deserted her offspring ; the love for home 

 predominating over every other feeling. 



•'These deviations from the usual style of nest-building by the Pewee 

 would seem to argue against the belief generally entertained, that in- 

 stinct, being a positive determination given to the minds of animals for 

 certain purposes, must necessarily be perfect, when viewed in connection 

 with those purposes ; but to say that they doubtless imply a change of 

 instinct is to perplex the understanding by a perversion of language. 

 But to ascribe these changes to the operations of reason influenced by 

 motives, does seem to be the most rational view to take of the subject. 

 That reason does enter into the inferior creatures, and dictate many of 

 the changes of habit which mark their career, has been shown in many 

 instances ; but I cannot forbear to record one which came under my 

 observation in the spring of 1871. While watching a pair of Ampelis 

 cedrorum, engaged in the building of a nest on a branch of an apple- 

 tree, it occurred to me that, by supplying them with materials, I might 

 secure a nest neater and more compact than those usually made. The 

 birds entered into the project with readiness, and carried away every 

 l)iece ol" colored string and cotton fabric with which 1 supplied them. 

 After I had ceased to furnish the materials they would fly repeatedl)' to 

 the branch where the articles were dei)0sited, as if imploring my serv- 

 ices. The result was a nest firmer, more symmetrical, and more elegant 

 in proportions than any I had ever observed. If instinct had been the 

 controlling principle in this case, the birds would not have given my 

 labors so much attention ; but admitting that they had been actuated 

 by leasoning faculties in their selection, the whole thing is perfectly 

 plausible. Instinct is always the same thing ; it never advances, never 

 retrogrades ; but reason tends to improvement, when it can serve a good 

 pur])ose. 



"As the nests which form the subject-matter of this paper were found 

 within a short distance of each other, it would seem that circumstances 

 peculiar to the neighborhood had nnidered a deviation from the common 

 form tu'cessary. Observation tea(;hes us thiit when danger or any other 

 circumstance renders a change in the character of the nest necessary, 

 that deviation is made in an equal degree and in the same manner by 

 all the birds of one species, and that it does not extend beyond the 

 limits of the region wliere alone it can serve a good purpose.'' 



CONTOPUS BOREALIS, (Sw.) Bd. 

 Ollve-slded Fljcatclier. 



Tiirarnim borealis, Sw., F. B. A. ii, 18:11, 141, pi. 35. 



ili/iuhiti.t borealiit, Gkay. Gt;n. of IJ. i, 248. 



Cdiilopux borealis. Bo., B. N. A. 1858, 188.— Coop. & Sv'CK., N. IT. Wash. Tor. 18G0. 169.— 

 ScL., Cat. IHti-i, y:?0 (not of T. Z. S. 1858, :}U1 ; 18r)'.». 4:5; wliidi aro C. pir- 

 tiiiax). — Vkuk., I'r. Ess. Inst. iii. 145 (Norway. Mi-.. probaMy hn-cdinu;. not 

 very roinnion ; ijuite connnon about Unilja^oj;). — Ai.i.ic.N, I'r. Ess. Inst, iv, 

 1804, 54 (Massat'lin.sctts, not vt-ry rare; May 15 to Sfjit. 15). — CouES, ibid, v, 

 1868, 264. — McIlwi:., ibid, v, 1866^ 84 (Toronto, two siiccimeus). — L.vwH., Ann. 



