198 Phiuups, '• ' [April 



rian migrants to be referred to later, no two fall upon the same day. 

 They begin with - - on February 28 ami end with 



■nix on April 29, 



There is much to be learned as to the nesting localities oi late 

 and early arrivals inside a given species. It is certain thai some 

 birds wintering in Central America arrive in temperate summer 

 haunts and begin nest building almost before others of the saute 

 species start from winter quarters hound for suh-aretie regions, 

 the north hound birds starting later ami traveling faster. 



\- Cooke remarks in speaking of the Robin ' "The first robins 

 that reach a given locality in the spring are likely to remain there 

 to nest, and the advance of the migration time must await the 

 arrival of other birds from still farther south. Therefore each 

 robin undoubtedly migrates at a faster rate than the apparent 

 movement of his species as a whole. This is true of most, if not all. 

 of the other seemingly slow migrants 



We may now refer to the most elaborate study of migration yet 

 attempted, that outlined bj Otto Herman in Hungary " and given 

 in " Acpiila ' from year to year. Enormous numbers of stations 

 are in use and stress is laid on the common species. It must be 

 confessed however that the actual significance of these records 

 from our point of view is haul to determine because most of the 

 observers appear to have been masters of elementary seh«.x>ls and 

 others not skilled in nek) work. It is more than likely that many 

 stations would show a delay in arrival not actually present. In 

 Vol. XII, I905j p 226, there is. however, a table showing the com- 

 bined dates of arrival of 16 species from 1894 to 1903, 

 yearly error, as compared with a ten year mean date of arrival, 

 has been computed, and shows - onstant birds the following 



. -id Oriohti - with an env 



sai with an error of only 1.4 days. 



I have computed the average error of these same species for a 

 later period. UXM to 1910, using the 'Aquila" tables and find it 

 be 2.2 days '""•»". 



Vol. XVIII, 1911, of 'Aquila* gives t v show- 



s 



ss 



