356 FRANCIS H. HERRICK 



the female sat over the eggs for three-quarters of an hour, but 

 then retired and was not seen at the nest again until the follow- 

 ing day. After the third egg was laid in the morning of June 

 6, the female was at the nest almost constantly, and incubation 

 was regularly established. On this day one of the eggs was seen 

 to be nicked, and the next day it had disappeared, presumably 

 removed by the bird. In respect to such conduct there is great 

 difference in individuals. iVs nearly as could be ascertained 

 incubation lasted i6 days. 



Building of the Oriole's N^est. — The Baltimore oriole (Icterus 

 baltimore) is undoubtedly our greatest nest-builder; it is a 

 " weaver " of one of the most secure and durable nests known, 

 and so intricate is the product of its "loom," it is perhaps not 

 to be wondered at that remarkable feats of engineering skill 

 have been attributed to it, especially by popular writers. I 

 was naturally on the lookout for any marked exhibition of in- 

 telligence above the usual plane of association, but in this respect 

 w^as disappointed. The oriole works throughout as if stirred 

 by the same kind of impulses which spur a robin or a vireo 

 to their peculiar tasks. There is a method of working char- 

 acteristic of each, and upon the whole there is the same type 

 of behavior repeated for the hundredth or the thousandth time, 

 with slight variations, as in the many instances already re- 

 corded. If my account seem tedious, some allowance must be 

 made for this fact. 



The observations which follow give a fairly complete history 

 of the construction of a single nest which was strung at a height 

 of 20 feet, to the pendent spray of an elm on a frequented street 

 in Cleveland Heights Village, Ohio. These notes are illustrated 

 by four sketches (figs. 19-22) made on the spot, and revised 

 by comparisons with the completed nest which was taken down 

 after the birds were through with it. Such drawings are nec- 

 essarily diagrammatic, and serve only to record general im- 

 pressions. When first observed at 6.10 p. m., May 14, a few 

 gray bast fibers had been wound to one tvvig only, number I 

 in figure 19." A year later I saw a female oriole laying her 



" It may be that the primary point of support was on the twig to the riglit, ( No. ii) 

 but this does not matter for purposes of description, only it should be noted that if 

 this were the case the other twigs (Nos. iii-vi, fig. 19) were taken up in reverse order. 

 The fact of particular interest was that the final gap of the nest wall to be filled 

 in, as in the case of the vireo, was on the side opposite the primary points of support. 



