The Abert Towhee 



or trees. Eggs: 3 or 4; pale bluish green (much paler than pale niagara green), 

 marked sharply and sparingly, often curiously, and chiefly at the larger end, with black 

 or deep brownish black, rarely with subdued shell-markings of purplish gray. The 

 markings sometimes group into a wreath of interwoven hieroglyphics, and the eggs 

 are at such times, or indeed at all times, roughly comparable to those of the Agelaius 

 Redwings. Av. of 80 southern Arizonian specimens in the M. C. O. coll.: 24.2 x 18 

 (•955 x -7 1 )- Extremes 21.6-26.9 by 17-18. 8 (.85-1.06 by .67-. 74). 



General Range. — Chiefly resident in Lower Sonoran zone from the Colorado 

 Desert, southern Nevada and southwestern Utah, south through Arizona to south- 

 western Mexico. May wander a little farther south in winter. 



Distribution in California. — Common resident in the valley of the Colorado 

 River, Imperial Valley, and the Colorado Desert west to Whitewater and Palm Springs. 



Authorities. — Baird, Rep. Pac. R. R. Surv., vol. ix., 1858, p. 516 (Fort Yuma); 

 Cooper, Orn. Calif., 1870, p. 244 (Colorado Valley; habits, nests and eggs) ; Brewster, 

 Bull. Nutt. Orn. Club, vol. vii., 1882, p. 198 (s. Ariz.; habits; desc. nests, eggs and 

 young) ; Gilman, Condor, vol. v., 1903, p. 12 (w. Colorado Desert; nests and eggs); 

 Grinnell, Univ. Calif. Pub. Zool., vol. xii., 1914, p. 177 (Colorado R.; habits, crit.). 



ORNITHOLOGY, it cannot be too often repeated, is not an exact science. Tax- 

 onomy, the science of classification, aims at exactness, but its symbols are, after all, only 

 records of opinion. Bird names, however diligently Latinized, are only pegs driven at 

 irregular intervals along memory's wall, pegs upon which we may conveniently hang 

 bundles of collective experience. These thought bundles, or observations, are called 

 facts, and they pertain to, or are derived from, individual birds having certain points 

 of resemblance, or certain characteristics in common. These rows of thought pegs are 

 called family, genus, species, and subspecies, solely according to the nature and degree 

 of resemblance between individuals which we choose to regard. And of all these 

 ranks, or orders, or rows of pegs, the most familiar, the most useful, the best under- 

 stood, and for that very reason the least accurate, is the species row. Beneath each 

 peg of this row we paste a label called a scientific name, which must be dutifully re- 

 peated every time an individual bird is mentioned, and upon the peg itself we hang 

 all the similarities which we may discover between two or more individuals not other- 

 wise defined (that is, whose origin, or distribution, or actual blood relationship, is 

 unknown to us). 



I have said these name pegs are driven at irregular intervals. They should be if 

 they expressed the facts of nature as we find them. The distance between the pegs is 

 precisely the interesting point in any comparison of species. These distances vary 

 enormously, but our practical realization of this fact is always being hindered or frus- 

 trated by a practical, or rather an impertinent, consideration which pertains to the 

 mechanism of our science. The assignment of two or more names to two or more 

 pegs tends in itself to prescribe the distance between those pegs. That distance is the 

 space separating two names on the printed page. For economy's sake, names are 

 printed in close succession, and for the sake of appearance they are separated by regular 

 intervals. We tend, thus, to a uniformity of peg-spacing upon memory's wall, and so to 

 a sense of uniform value-distances separating the species themselves. Yet nothing 

 could be further from the facts. In truth, this artificial, constricted spacing of our 



J 



98 



