Scott on Birds observed at Twin Lakes, Colorado. 91 



I shall simply give those absolutely noted, passing the better known 

 with but a word to indicate their occurrence. As a whole, this 

 seems to be a very thickly populated region, considered ornitho- 

 logically, there being very many individuals of nx)st of the species 

 noted. 



1. Tardus migratorius. Robin. — Very comraon at the level of the 

 Lakes. Begins to breed about June 5. The breasts of the males are more 

 tawny, and the general coloring lighter, than in individuals from the East- 

 ern States. Young fully fledged were observed June 29. All the nests 

 found are curiously built of sage-brush, and the " mud walls " were not 

 prominent. 



2. Turdus pallasi. Hermit Thrush. — Not common. Noted on 

 the hills to the south of Lower Lake. 



3. Oreoscoptes montanus. Mountain Mocking-Bird. — Not 

 common. Not met with about the Lakes, but at a point five miles north 

 in a small park. 



4. Sialia arctica. Arctic Bluebird. — Abundant. Breeds about 

 June 1 in deserted Woodpeckers' holes and hollow trees. 



5. Cinclus mexicanus. Water Ouzel. — Not common. Occur 

 above the Upper Lake on the stream flowing into it, and on the Arkansas 

 River at the junction of Lake Creek. On the 22d of June I found a pair 

 on a pond of still tcater about a hundred yards from the stream that flows 

 into the Lakes, the pond and stream not being connected. The female 

 showed no signs of having laid eggs or of incubation. This pair was not 

 at all shy, allowing my close approach as they walked about on some float- 

 ing logs feeding on the aquatic larvae that abounded. 



6. Regulus calendula. Ruby-crowned Kinglet. — Abundant. 

 One of the most common song-birds, and heard everywhere. On the 20th 

 of June I saw a female fly to a pine-tree with material in her bill for build- 

 ing a nest. On looking I found a nest nearly finished. On the 25th of 

 June I took<this nest with five fresh eggs, and the female showed signs of 

 having incubated. I think no more eggs would have been laid. The nest 

 is before me as I write, and presents the following peculiarities : It is semi- 

 pensile, being suspended to the leaves of the pine, and to one small branch, 

 much like the Red-eyed Vireo's nest. It is very large in proportion to the 

 builder, and is made of the bark of sage-brush and of green moss very 

 firmly twisted together, and forming a soft outer wall, of from half to a full 

 inch in thickness. This is lined with feathers and hair. The whole nest 

 is very soft, and has the following dimensions : Four inches deep outside ; 

 three inches deep inside ; three inches in diameter outside, and two inches 

 at the top inside, but narrowing to an inch and a haK at the bottom. On 

 the outside it is as wide at the bottom as at the top, being in this respect 

 like a Baltimore Oriole's. It was placed at the very outermost twigs and 

 leaves of the tree, about twelve feet from the ground. The eggs are five 



