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



citta s. diademata, Penthestes g. gambeli, Dendragapus o. ohscurus, 

 Nucifraga columbiana, Loxia c. bendirei and other boreal birds which 

 need not be mentioned here were common. Birds at this altitude 

 were not as abundant as lower down but were far more interesting 

 to us because of their northern affinities. 



MiGKATION. 



The spring migration here at the edge of the foothills was on an 

 average about a week later than it was on the plains east of Denver, 

 showing in all probability, that the birds came into this region 

 from the plains area. Some species, as the Juncos, which had 

 wintered in the foothills, moved down toward the mouths of the 

 gulches and then migrated north, so that we noticed two distinct 

 movements here, that of spring migrants from the south advancing 

 up the gulches, and that of winter residents coming out of the foot- 

 hills and leaving for the north. 



Some species that had nested higher in the mountains began 

 coming down in August into this country so that during this 

 month we found considerable movement among the birds, noting 

 several species as Sphyrapicus thyroideus, and Myiochanes r. 

 richardsoni, that had not nested here but which became common 

 then. Others as Selasphorus platycercus, Spizella p. arizonw and 

 Sialia currucoides increased greatly in numbers at this time. 



There was a general tendency among the young birds of the 

 higher zone breeders to work down the slopes through July and 

 August, and this movement was more marked when the true migra- 

 tion began in September. Bird life in the higher altitudes was at 

 all times rather local in its distribution and some localities, which 

 appeared favorable to the presence of birds, as Mount Vernon 

 and Turkey Creek Canons, supported a very small number of 

 species and individuals. 



Our first trip into this region was made March 28, 1909, on which 

 date we discovered practically no signs of approaching spring in 

 the mountains and the typical winter birds were the only ones seen. 

 Following this we made weekly one day trips almost without 

 exception until November 14, on which date the last sign of sum- 



