PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 163 



191. Plegadis guarauna, (Gm.) 



Resident, bat much more common in summer than in winter. On the 

 16th of May, 1877, Mr. G. B. Sennett and I visited a large patch of tule- 

 reeds growing in a shallow lagoon, about ten miles from the fort, in 

 which large numbers of this Ibis and several kinds of Herons were 

 breeding. The reeds covered an area of perhaps seventy-five acres or 

 less, growing in water three or four feet in depth. Irregular channels 

 of open water traversed the reeds here and there, bat the bottom was 

 comparatively firm, and there was little difficulty in wading in any 

 direction. Besides the Ibises, the Great and Little White Egrets, Lou- 

 isiana and Night Herons, and several other birds were breeding here. 

 Often nests of all these species were placed within a few feet of each 

 other, but there was a tendency towards the different kinds forming 

 little nesting groups of ten or fifteen pairs. The reeds grew about six 

 feet above the surface of the water, and were either beaten down to 

 form a support for the nests, or dead and partly floating stalks of the 

 previous year were used for that purpose. 



It was impossible to estimate the number of the Ibises and different 

 Herons nesting here. On approaching the spot, many would be seen 

 about the edges of the lagoon or flying to or from more distant feeding 

 grounds, but upon firing a gun a perfect mass of birds arose, with a noise 

 like thunder, from the entire bed of reeds, soon to settle down again. 



Both nests and eggs of the Ibises were quite unlike those of any of the 

 Herons, and could be distinguished at a glance. The nests were made 

 of broken bits of dead tules, supported by and attached to broken and 

 upright stalks of living ones. They were ratber well and compactly 

 built, and were usually well cupped, quite unlike the clumsy platforms 

 of the Herons. The eggs were nearly always three in number, and at 

 this date were far advanced in incubation ; many nests contained young 

 of all sizes. Fifty eggs now before me average 1.95 by 1.35, the extremes 

 being 2.20 by 1.49 and 1.73 by 1.29 ; they are decidedly pointed at the 

 smaller end, and are of a deep bluish-green color. 



On May 7 of the following year, I revisited this heronry, but there were 

 no nests, and very few Ibises or Herons were to be seen. I am inclined 

 to think that they moved to some other part of the extensive prairie, in 

 several parts of which were beds of reeds similar to the one above 

 described, but I was prevented by sickness from making any further 

 investigations. 



The young, when first hatched, are clothed in blackish down; the bill 

 is whitish, with dusky base. When nearly fledged, the wings and back 

 have a very marked metallic lustre ; the base of bill, with terminal one- 

 fourth inch and a two-fifths inch median band, black ; the intervening 

 portions pinkish-white. — (Ibis ordi, Dresser, Ibis, 1866, 32. — Falcinel- 

 las g., Sennett, B. Eio Grande, 56.) 



