NUTTALL'S WHITE-CROWNED SPARROW 1295 



simultaneous mates of male I. The description is taken from Barbara 

 D. Blanchard (1941) : 



With the approach of reproduction * * * each female created for herself a 

 subdivision of the main territory which she defended against the other female by 

 loud singing and fighting, and in which she finally chose her nest site. From 

 February 1 until late March, by which time both had nests, each female sang 

 frequently from a favorite perch within her section. * * * Twice, when female 

 III followed the male toward the section which belonged to female I, a fight ensued 

 between the two females. They locked feet and jabbed each other on the breast. 

 * * * Had they not been banded, I should have thought I was watching a 

 boundary dispute between two males. 



Territory. — Just as the behavior involved in territory establishment 

 is nearly identical in the four races, so is the nature of the site chosen 

 for the territory. Despite the variety of climatic and vegetational 

 zones in which the four races nest, all the territories I have observed 

 are strikingly similar in their appearance. So marked is the similarity 

 that I think it must reflect deep seated preferences common to the 

 western portion of the species — a conservative psychological theme 

 with minor racial variations. 



The similarity in appearance of the white-crowned sparrow terri- 

 tories at different latitudes and altitudes lies not in the presence of 

 any one common element — such as a particular species of plant — or 

 in any one topographic feature, but in a subtle yet definite combina- 

 tion of three elements: grass, bare ground, and shrubbery. These 

 invariably exist in each male's territory. Two other elements are 

 usually present near each territory but not necessarily within it: 

 water, either salt or fresh, and tall trees. 



The nature of the grass, bare ground, and shrubbery vary with 

 climate and topography. The grass may be pure or mixed with 

 lichens or mosses or sedges and small flowering plants. The bare 

 ground may be a sandy beach or the rocky shore of a lake or river. 

 It may be a road or a pack trail, a ploughed field or a clearing in the 

 forest. The shrubbery may consist of any species of plant, native or 

 exotic, that grows thick enough to shelter a nest or to provide a roost. 

 Bracken fern, scrub conifers and alders and willows, salal, Labrador 

 tea, lupine or rose or Artemesia bushes, and many exotic ornamental 

 shrubs are examples of plants that make up this common element. 



To list the three elements and the forms they take in different 

 climates is not, however, to define a white-crowned sparrow's territory. 

 Rather it must be understood in terms of the bird's temperament 

 and habits. It seems to me that the essential feature is the mixture 

 of grass, bare ground, and shrubbery in just the right proportions to 

 permit ground foraging with quick escape to shelter. The areas of 

 bare ground and grass must be large enough to facilitate foraging, 

 but not so large as to require the birds to move more than a few wing- 



