Vol. 32, pp. 11-14 February 14, 1919 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTION OF A NEW RACE OF THE WESTERN 



GULL 



BY JONATHAN DWIGHT, M. D. 



The breeding range of the Western Gull is singularly long 

 and narrow, extending north and south some 1,500 miles along 

 the Pacific Coast, but it is scarcely wider than the rocky islands 

 lying off the coasts of Washington, Oregon, California and Lower 

 California which the birds frequent. It is therefore not at all 

 surprising that it is separable into two races, the southern one 

 having a darker mantle with less gray on the primaries. Audu- 

 bon described Larus occidentalis in 1839 from two specimens 

 sent him by his friend, Dr. J. K. Townsend, one an adult 

 male, the other an immature bird at least a year old, both taken 

 at Cape Disappointment, mouth of the Columbia River, Wash- 

 ington. October 7th and 6th respectively, 1836. The type was 

 once in the U. S. National Museum collection, No. 2767, so 

 I am informed by Dr. Chas. W. Richmond, but it can not be 

 found there to-day; hence Audubon's description must deter- 

 mine which of the two races he had in hand. It is perfectly 

 evident that he did not have the dark southern race, for al- 

 though his description is faulty in some respects it fits fairly 

 well the birds that breed to-day on the islands off the coasts of 

 Washington and Oregon. Therefore it is the southern race 

 with the dark mantle that requires a new name. 



Larus occidentalis livens, subsp. nov. 



Type, d adult, No. 3378, L. C. Sanford collection, San Jose Island, 

 Lower California, April 26, 1912. Collected by W. W. Brown, Jr. Wing, 

 420 mm.; tail, 165; tarsus, 70; middle toe without claw, 62; culmen, 55; 

 depth of bill at base, 21; at angle, 22. 



5— Pkoc. Biol. Soc. Wash., Vol. 32, 1919. ( 11) 



