1^8 Dwight on the Horned Larks. [April 



THE HORNED LARKS OF NORTH AMERICA. 



BY JONATHAN DWIGHT, JR. 



Since Mr. Henshaw's review of this group six years ago 

 (Auk, Vol. I, 1S84, p. 254) his collection of birds has passed 

 into the British Museum, and much of his valuable material has 

 not been available for study in the present connection, but the 

 loss of this has been more than compensated by the immense 

 number of specimens kindly placed at my disposal by many 

 members of the American Ornithologists' Union. Over 1 200 were 

 sent to the last meeting of the A. O. U., by request of the Committee 

 of Arrangements, and since then I have examined many others, 

 bringing the grand total up to 2012. Such a magnificent series of 

 birds of one species has probablv never before been brought to- 

 gether, and including, as it does, birds from all portions of the conti- 

 nent and at all seasons of the year, it affords a wonderful opportunity 

 for the study of plumage and geographical variation, and at the same 

 time brings one face to face with the question, as yet unsolved, of a 

 nomenclature that, without being cumbrous, will fit the many 

 groups, intergrading one with another, into which the North 

 American genus Otocoris is certainly separable. Binomialism, 

 based on the fixity of species, will not suit the Horned Larks, for 

 from the Atlantic to the Pacific, and from the Arctic down into 

 Mexico. I can form a chain of differing groups that, nevertheless, 

 pass insensibly from one to the other, absolutely without break. 

 Trinomialism gives relief, but it does not provide for exactly in- 

 termediate specimens, nor does it formulate a rule under which 

 subspecies may be established, but leaves the matter to the vary- 

 ing taste of every student. However, it is not mv purpose to 

 discuss nomenclature, and I trust the conclusions I have reached 

 will be sufficiently conservative to meet with the approval of 

 those who have had to deal with the same difficulties. 



Accepting trinomialism as it is today, T have applied the fol- 

 lowing rule to my study of the Horned Larks, i. e., to recognize 

 as races groups of birds that during the breeding season occupy 

 definable areas over which similar conditions of climate and vege- 

 tation prevail, and that show differences of size or plumage at 

 the centres of such areas, which may be readily recognized and 



