332 Rockwell and Wetmore, Birds of Golden, Colorado. [j^jy 



ragged and not until September 19 were birds in full fall plumage taken. 

 These birds were found almost entirelj- in the pines and had about the same 

 habits as the preceding species. The Mountain Chickadee could be 

 distinguished by its notes with ease as it drawled them out in a different 

 tone from that of P. a. septentrionalis. During August the young worked 

 slowly down the slopes of the mountains and on October 16 were seen on 

 Clear Creek below Golden and from this on were common there. 



103. Regulus calendula calendula. Ruby-crowned Kinglet. — 

 Noted once in the spring but fairly common in the fall migration. The 

 first one was seen September 19 and the last one October 19. In the moun- 

 tains they were found in the quaking aspen thickets, but the first week in 

 October they were also common along Clear Creek. 



104. Myadestes townsendi. Townsend's Solitaire. — Common in 

 the mountains above 7,000 feet and occurring down to the plains. During 

 the spring it was first seen April 18 and was common singly or in small 

 flocks until May 2. The birds were ground feeders and were eating 

 Kinnikinnick berries and what insects they could pick up. In their 

 actions they reminded us strongly of Robins at times and again of Bluebirds. 

 They always chose the topmost twig of a tree for a perch, and dead limbs 

 were favorites with them, but on windy days they took refuge within the 

 pines. We found it rather hard to approach them though usually they 

 only flew a short distance. In the fall the first bird was taken August 22, 

 but they were not found again until October 10. They were fairly common 

 until November 7, when the last one was seen. On this date they were 

 found in sunny hollows on the side slopes and were singing a low warbling 

 song. In the fall they were much more common in the gulches at the lower 

 levels, and were feeding on choke-cherries to some extent. The one taken 

 August 22 was moulting from the spotted juvenal plumage. Fall birds 

 showed more white on the tertials than those secured in the spring. 



105. Hylocichla ustulata swainsoni. Olive-backed Thrush. — 

 Common migrant in the spring but not noted in the fall. First seen May 

 9 and the last one taken June 6. On the latter date we secured a single 

 bird in a thicket of quaking aspens on Lookout Mountain, and on picking 

 it up noticed a hard lump in the throat. On dissection we found it to be a 

 medium sized ground beetle whose claws, catching in the oesophagus had 

 swung the body around and held it there partially closing the aperture. 

 Several other insects were lodged against the obstruction but the bird did 

 not appear to be distressed by it as it was fat and in good plumage. Mr. 

 E. J. Oslar kindly identified the beetle as Aphodius sp., a common repre- 

 sentative of the family Scarabceidce. This wound was apparently at least 

 two weeks old as the gullet was healed completely and the skin dried down 

 hard around the obstruction. 



106. Planesticus migratorius propinquus. Western Robin. — 

 Common everywhere. On the plains thej^ were paired by the end of the 

 first week in April but in the mountains we found them occurring in loose 

 flocks as late as June 6 though they began breeding immediately afterwards. 



