1917-] Recently published Ornithological Works. 439 



mean date for the first hearing of the son<^ of the Song- 

 Thrush was January \7 , five days earlier than the 25 years' 

 mean, Januai-y 23. The mean date for the first Swallow of 

 1915 was April 22, four days later than the mean date, 

 April 18. The Cuckoo's mean was April 28, four days 

 late, and the Flycatcher's May 10, five days early. In 

 addition to these observations, continuously recorded for 

 twenty-five years, the authors commenced in 1914 a new 

 table with observations on the arrival-date of some twenty 

 of the commoner migrants. This will undoubtedly even- 

 tually be of great value in fixing the average arrival-date 

 of these species, but at present the observations have not 

 yet continued through a sufficient number of years to make 

 any definite deductions. 



We should like to draw the attention of all those interested 

 in migration, and especially the members of the migration 

 committee of the B. 0. C, to these valuable reports and 

 tables. As they are published in a journal not usually 

 consulted by ornithologists, there is some risk of their 

 escaping notice. 



Dixon on the Yellow-billed Loon. 



[Migration of the Yellow-billed Loon. By Joseph Dixon. Auk, 

 xxxiii. 1916, pp. 370-376.] 



Mr. Dixon, who spent a considerable time during 1913 

 and 1914 on the arctic coast of Alaska, corroborates to a 

 great extent the late Prof. Cooke's views on the subject of 

 the migration I'oute of the Yellow-billed Loon ( Gavia or 

 Colymbus adamsi) mentioned in ' The Ibis '' (1916, p. 358). 

 Although he and his companions noticed numbers of 

 these birds in June and early July, no evidence of nesting 

 or breeding was obtained, and the spring migration route 

 appears to run from eastern Asia to Bering Strait, Point 

 Barrow, and the Mackenzie Delta, and thence probably up 

 the Mackenzie River to breeding-places in the interior, 

 No evidence of the return autumnal migration was obtained 

 by Mv. Dixon. 



