EASTERN FOX SPARROW 1395 



not uncommonly found. In the southern portion of the range three is the number 

 most frequently found, and two are often recorded. There is considerable evidence 

 that at least some of the northern races regularly rear two broods in a season while 

 those farther south rear but one. 



All other features of the species' habits Linsdale was able to compare 

 showed little or no observed variation between the different popula- 

 tions. He was hampered by the fact that, as he expressed it, " * * * 

 many phases of its life-history are too little known. Especially 

 desirable is more recorded information concerning the behavior of 

 the birds through the breeding season." And he pleads "It is hoped 

 that this summary of the available literature may serve as a basis 

 for a more thorough investigation of the natural history of Passerella 

 iliaca." 



Despite Linsdale's plea, we know little more about the species' 

 biology and ethology today than we did 30 years ago. In defense 

 of this continued ignorance, it must be admitted that the species' 

 innate shyness, a dominant trait in all its populations, makes it a most 

 difficult subject to work with in the field. It is doubtless mainly for 

 this reason that no intensive, detailed life history or behavioral study 

 of any of the fox sparrows has ever been made. As the following 

 accounts bear witness, nowhere in the literature is the courtship 

 described, or the species' territoriality, or the sexes' sharing of the 

 various natal chores, to name only a few features badly in need of 

 further investigation. 



PASSERELLA ILIACA ILIACA (Merrem) 



Eastern Fox Sparrow 

 Contributed by Lewis McIver Terrill 



Habits 



The fox sparrow was first described by the German zoologist, 

 Blasius Merrem, under the name Fringilla iliaca in 1786. In 1837 

 William Swainson erected for it the genus Passerella (Italian di- 

 minutive of Passer, sparrow), to which it is still assigned. The 

 genus contains only this single species, which is endemic to North 

 America and occurs at one season or another from the Atlantic to 

 the Pacific and from the southern border of the United States north- 

 ward to the limit of tree growth. Over this extensive range the 

 current A.O.U. Check-List (1957) recognizes a total of 18 subspecies, 

 and the fox sparrow's marked geographical variation is thus exceeded 

 by only two other North American bird species, the horned lark and 

 the song sparrow. 



