But what was the cause of this particular bird's intense solicitude? It was obvious there was a nest in the neighborhood. As I sought in the grass and weed-clumps, he uttered his piercing calls of protest and circled and hovered overhead like a red-winged blackbird. Suddenly the thought occurred to me that the flycatchers of my acquaintance do not nest on the ground, but on trees. I looked around, and, sure enough, in the shallow hollow below me stood a solitary willow tree not more than fifteen or twenty feet high, the only tree to be seen within a mile. And that lone tree on the plain was occupied by the flycatcher and his mate for a nesting place. In a crotch the gray cottage was set, containing three callow babies and one beautifully mottled egg. In another fork of the same small tree a pair of kingbirds--the same species as our well-known eastern bee-martins--had built their nest, in the downy cup of which lay four eggs similarly decorated with brown spots. The birds now all circled overhead and joined in an earnest plea with me not to destroy their homes and little ones, and I hurriedly climbed down from the tree to relieve their agitation, stopping only a moment to examine the twine plaited into the felted nests of the kingbirds. The willow sapling contained also the nest of a turtle dove. "If there are three nests in this small tree, there may be a large number in the cluster of trees beyond the swell about a mile away," I mused, and forthwith made haste to go to the place indicated. I was not disappointed. Had the effort been made, I am sure two score of nests might have been found in these trees, for they were liberally decorated with bird cots and hammocks. Most of these were kingbirds' and Arkansas flycatchers' nests, but there were others as well. On one small limb there were four of the dangling nests of Bullock's orioles, one of them fresh, the rest more or less weather beaten, proving that this bird had been rearing broods here for a number of seasons. Whose song was this ringing from one of the larger trees a little farther down the glade? I could scarcely believe the testimony of my ears and eyes, yet there could be no mistake--it was the vivacious mimicry of the mocking-bird, which had travelled far across the plain to this solitary clump of trees to find singing perches and a site for his nests. He piped his musical miscellany with as much good-cheer as if he were dwelling in the neighborhood of some embowered cottage in Dixie-land. In suitable localities on the plains of Colorado the mockers were found to be quite plentiful, but none were seen among the mountains.