170 NORTH AMERICAN BIRDS. 



by destroyiiij^' tlie swarms of young grasshopj^ers. On tlie writers land tlie 

 grasshoppers had deposited tlieir eggs hy the million. As they began to 

 liateh, the YeUow-heads found them out, and a tlock of about two hundred 

 attended about two acres each day, roving over the entire h>t as wild 

 j)igeons feed, the rear ones Hying to the front as the insects were devoured. 



Mr. Clark met with tlu^se birds at New Leon, Mexico. Thev were always 

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

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

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

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

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

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



Dr. Kennerly founil them very common near flanos and also near Santa 

 Cruz, in Sonora. At the former })lace they were seen in the month of April 

 in large Hocks. 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 Hocks of many thousands 

 with the species of Ayclaitis, and on the ai»proach of spring separate into 

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

 where they incubate. Their nests he found attached to the ui)right stalks 

 of the reeds, and woven around them, of Hexible grasses, dittering essen- 

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

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

 jfreen, thickly covered with minute dots of a lit-ht umber-brown. 



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

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

 wholly on the ground, in com])anies, the sexes separated by themselves. 

 They were digging into the earth with their ])ills in search of insects and 

 larvie. They were very active, straddling about with a quaint gait, and now 

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

 ko-knk he-ait. Their music was inferior even to the harsh n<jtes of M. 

 2)ecoris. 



Se\eral nests of this species, ])rocured 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 liad a diameter of three and a depth of two and 

 a half inches. The base, periphery, and the 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 were made of finer materials of the same. Thev were 

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

 Hags, 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, 



