170 NORTH AMERICAN BIRDS. 



by destroying the swarms of young grasshoppers. On the writer's land the 

 grasshoppers had deposited their eggs by the million. As they began to 

 hatch, the Yellow-heads found them out, and a Hock of about two hundred 

 attended about two acres each day, roving over the entire lot as wild 

 pigeons feed, the rear ones flying to the front as the insects were devoured. 



Mr. Clark met with these birds at New Leon, Mexico. They were always 

 in flocks, mingled with two or three of its congeneric species. They were 

 found more abundant near the coast than in the interior. There was a roost 

 of tliese birds on an island in a lagoon near Fort Brown. Between sunset 

 and dark these birds could be seen coming from all quarters. For about an 

 hour they kept up a constant chattering and changing of place. Another 

 similar roost was on an island near the mouth of the Eio Grande. 



Dr. Kennerly found them very common near Janos and also near Santa 

 Cruz, in Sonora. At the former place they were seen in the month of April 

 in large flocks. He describes them as quite domestic in their habits, prefer- 

 ring the immediate vicinity of the houses, often feeding with the domestic 

 fowls in the yards. 



Dr. Heermann states that these birds collect in flocks of many thousands 

 with the species of Agdaias, and on the approach of spring separate into 

 smaller bands, resorting in May to large marshy districts in the valleys, 

 where they incubate. Their nests he found attached to the upright stalks 

 of the reeds, and woven around them, of flexible grasses, differing essen- 

 tially from the nests of the Agclaii in the lightness of their material. The 

 eggs, always four in number, he describes as having a ground of pale ashy- 

 green, thickly covered with minute dots of a light umber-brown. 



Mr, Nuttall states that on the 2d of May, during his western tour, lie saw 

 these birds in great abundance, associated with the Cowbird. They kept 

 wholly on the ground, in companies, the sexes separated by themselves. 

 They were digging into the earth with their bills in search of insects and 

 larv?e. They were very active, straddling about witli a quaint gait, and now 

 and then whistling out, with great effort, a chuckling note, sounding like 

 ko-kitk kie-ait. Their music was inferior even to the harsh notes of M. 

 pecoris. 



Several nests of this species, procured in the marshes on the banks of 

 Lake Koskonong, in Southern Wisconsin, were sent me by Mr. Kumlien ; 

 they were all light, neat, and elegant structures, six inches in diameter and 

 four in height. The cavity had a diameter of three and a deptli of two and 

 a half inches. The base, periphery, and jthe greater portion of these nests 

 were made of interwoven grasses and sedges. The grasses were entire, with 

 their panicles on. They were impacted together in masses. The inner por- 

 tions of these nests M'ere made of finer materials of the same. They were 

 placed in the midst of large, overflowed marshes, and were attached to tall 

 flags, usually in the midst of clumps of the latter, and these were so close 

 in their growth that the nests were not easily discovered. They contained. 



