2^6 IIensiiaw ov l/ic North American Shore Larks. I .l"ly 



especially in the territory to the north of the boundary — in British 

 America, Alaska, etc. — the bird partakes more of the character 

 of a true migrant, and every fall and winter witnesses the intrusion 

 from the north into our territory of hordes of these birds. How 

 for south these northern birds penetrate is at present not deter- 

 minable with accuracy. Judging from specimens at hand the 

 37th parallel marks about the southern limit. From the intrusion 

 of these northern-born birds into regions where the summer resi- 

 dents only partially migrate, or do not migrate at all, there results 

 a mixing up of the geographical races which is very puzzling. 

 As an instance in point, the writer may mention that at Carson, 

 Nevada, in November, he found two quite dissimilar forms, 

 neither of which represents the bird found at that locality in 

 summer. 



The movements of the Shore Larks appear to be chiefly lati- 

 tudinal, but they also wander to greater or less distances east or 

 west of their true homes. How extensive these longitudinal 

 movements are is not readily determined. The peculiarities of 

 one of the two forms found at Carson in November, as stated, 

 seem to show conclusively that it came from the region to the 

 westward, probably from across the mountains. If this supposi- 

 tion be correct, it would show that, in this instance at least, a 

 very considerable lateral movement had been made in search of 

 suitable food and climate. In itself this is not surprising, for 

 the Oregon Snowbird (^Jttnco orcgomis) is known to occur 

 abundantly in Colorado and Texas, as well as over the interme- 

 diate region, though it has not been ascertained to breed further 

 east than the Sierras, more than 600 miles to the west. How- 

 ever, at present there is too little known of the boundaries of the 

 several races of Shore Larks to enable any statements of value to 

 be made concerning the extent of their longitudinal movements. 



As the result of the accumulation of many years, the- Nation- 

 al Museum possesses a large series of these interesting birds, 

 collected in almost every portion of the country. Large as it 

 is, however, the material proved by no means sufiicient tor 

 the complete elucidation of the several races of this bird. The 

 great difficulty to a proper understanding of the mutual relation 

 of the forms in the past has been not so much the lack of a suffi- 

 cient number of specimens as a lack of specimens from the vari- 

 ous localities collected in the breeding season. From what has 



