4« 



NORTH AMERICAN "WARBLERS. 



This slow migration from New Orleans to Helena is noted in several 

 species, and seems to be due to the resting of the birds for several 

 days near the Gulf coast after their long flight. 



The average date of arrival at Helena for five years (1896-1901) is 

 April 2, with extremes of March 30, 1896 and 1897, and April T, 1901. 

 The average date of arrival at St. Louis is April 12, with extremes of 

 April 10, 1887, and April 17, 1885. The average of arrival at Water- 

 loo, Ind., is May 1; Chicago, May 8; Grinnell, Iowa, May 8; Lanes- 

 boro, Minn., May 9. 



The Texas records are also noteworthy. It is evident that there is 

 no regular progression from south to north. At a moderate rate of 

 speed it would take most species from ten to fifteen days to cross the 

 State, and yet the northern dates are on the whole earlier than the 

 southern. The explanation seems to be that the earlier birds in north- 

 ern Texas have flown across the Gulf to the upper part of the Texas 

 coast and moved inland from that point instead of crossing the Rio 

 Grande. 



The influence of altitude on bird migration is well illustrated by the 

 passing of parulas through Raleigh and Asheville, N. C. The latitude 

 of the two places is the same, but Raleigh is 300 feet above sea level 

 and Asheville 2,000. The records of spring migration at these two 

 points are as follows: 



Records of migraiion ofparula warbler in North Carolina. 



As would be expected, the birds appear in the mountains later than 

 on the plains, and it is considered that this is due to the efl^ect of the 

 higher altitude of Asheville. In the following case, however, there 

 is no such effect apparent. The town of Eubank, K3'. , is 200 miles 

 north of Helena, Ark. , and 85 miles south of St. Louis. It is at an 

 altitude of 1,000 feet and therefore 600 feet higher than St. Louis and 

 800 feet higher than Helena. The average date of arri\-al of the 

 parula warbler at Eubank for the eight je&vs 1887 to 1895 is April 

 9, with extremes of April 4, 1893, and xipril 14, 1887. This date is 



