abstracts: ornithology* 97 



are added 13 genera recently described or raised from subgenera; one 

 species and 14 subspecies either described as new, revived, or recently 

 captured within the boundaries of North America. Two species are 

 eliminated as synonymous, and one proposed subspecies is rejected for 

 the same reason. Furthermore there are many changes in names due 

 to the recognition of additional genera, the descriptions as new of the 

 North American representatives of wide-ranging species, the replacing 

 of later by earlier names, and similar causes. This brings the subject 

 down to December 31, 1916, and annual lists of the same character 

 are to follow hereafter. H. C. O. 



ORNITHOLOGY. — A cooperative bird census at Washington, D. C. 

 Harky C. Oberholser. Wilson Bull. 39: 18-29. March, 1917. 

 The importance of counting the actual numbers of birds over given 

 areas, particular!}^ during the breeding season, has already been shown. 

 Similar censuses during the height of the spring migration are also of 

 considerable value, both as a basis for comparison of the relative num- 

 bers of the different species in the same year and of the same species 

 in different years. Such a count was made by 15 local ornithologists 

 in the vicinity of Washington, D. C, on May 12, 1913. The country 

 investigated consisted of the region within 20 miles of the city of Wash- 

 ington and comprised the valleys of the Potomac and Anacostia rivers, 

 together with tributary streams and adjacent valleys. The routes of 

 the 13 parties, each of which covered a distance of from 5 to 55 miles, 

 traversed the country in all directions from Washington; and the 

 results were very interesting. One fact of distribution was emphasized 

 by these trips, which is that almost all the best places for birds about 

 Washington lie in the moi-e or less immediate valleys of the Potomac 

 and Anacostia rivers. On this day the total number of species ob- 

 served by all the parties was 129, of individuals actually counted, 

 1257. The largest number of species noted by any individual was 

 91, and the largest number of birds 3049. As the year 1913 was not 

 particularly good for birds, this record is likely to be much increased 

 by future observations. Three species, Podilymbus podiceps, Totanus 

 flavipes, and Dendroica palmarum hypochrysea, noted on this clay, had 

 not previously been observed so late in the spring. The six most 

 numerous species, in the order of their abundance, were, rather sur- 

 prisingly, as follows : Passer domesticus hostilis, Hirundo rustica erythro- 

 gastris, Iridiprocne hicolor, Melospiza melodia melodia, Chaetura pelagica, 

 and Lucar carolinensis. H. C. O. 



