20A. Barrows on Birds of the Loiver Uruguay. [October 



Blanca where it was occasionally seen running over the roofs of 

 the houses. Of its breeding habits I know nothing, but most of 

 the birds undoubtedly breed further south. 



78. Furnarius rufus {G?fi.). Hornero (Oven-builder). 

 — This bird has been so often and so thoroughly described that 

 I do not feel like saying much about it. Its familiarity with 

 man, its curiosity, its piercing notes and its strange, dome- shaped 

 mud nest are all well know^n. At Concepcion it is one of the 

 commonest residents and its nest may be seen in almost any 

 street. 



The nest is built of such mud as can be found near at hand, 

 and if the mud contain grass-roots or similar fibres so much the 

 better, but I do not think the birds worry themselves much 

 about the quality of the materials. Although the eggs may not 

 be laid until September or October, the birds often begin work 

 on the nest as early as the middle of June, thus occupying three 

 months or more in its completion. In fact I doubt if there is 

 any month in the year when one cannot find Oven-birds at work 

 on their nests. If the w^eather is dry they, suspend work for a 

 week or two until a shower refills the muddy pool from which 

 they draw their building material, when they go on leisurely as 

 before. This is the case only in winter, and when there is nothing 

 to cause haste. In spring and summer the case is entirely other- 

 w^ise ; a nest may then be begun and finished within a week. 

 But a winter-built house is usually much the best, and not a 

 few such withstand the rain and heat for a year or more if not 

 sooner pulled down by boys, iguanas, or birds of prey. The 

 clayey mud bakes almost to brick and it is no easy matter even 

 to break out a hole large enough to extract the eggs. The nests 

 are rather less than a foot in greatest diameter, and though the 

 eggs are not visible from the enti^ance the common statement 

 that there is an "ante-chamber" to the nest seems to me not 

 quite accurate. The nest is built very much like a spiral shell, and 

 if one could remove the inner whorls from such a shell as Ampu- 

 laria he would have quite a fair miniature of the Hornero's nest. 

 The eggs are seldom more than three in number, and are orig- 

 inally pure white, but being laid directly on the muddy floor of 

 the nest they soon acquire about the same color. I have taken 

 them from September 16 until January 15, but the larger 

 nvimber are, I think, laid during October. 



