50 
Book Notices and Reviews. 
The beak of the <? is stouter and shorter than the ? . 
Colouration, ricli red; violet neck; purple body band; black 
flights; purplish tail; shaped neck band; wing bars clear red 
and larger in area than those of the ?. 
[The above is of luuch interest, and if those of our mem- 
bers, who possess birds of which the sexes have been proved, 
would record sexual distinctions it would much increase the 
interest and practical utility of our Journal, there are many even 
well known species (Finches, etc., as well as Parrots), the out- 
ward sexual distinctions of which are but vaguely described — I 
would urge our members to send us many similar records to the 
above, Ed.] 
Booh Notices aiiD IReviews. 
Thk Biota of thp: San Bkrnardino Mountains, by Joskph 
Gkinnki.i,. The University Press, Berkeley, California, U.S.A. 
A glossary of contents was given in March i.ssue of tliis interesting 
work — of course it is the chapters referring to bird life and distribution that 
will appeal most to I'". B.C. Members. 
The chapter entitled — " General Considerations. Bird Population 
and Its Modifying Influences " — is of intense interest, tliough of course only 
a few broken quotations can be made therefrom in the space at onr 
disposal. 
" III the coastal lowlands of .Southern California, a condition manifests itself which has 
" been commented upon several times, but which, as far as I am aware, has not been ex- 
" plained. I refer to the almost universal exodus in July of many of the birds of the 
" summer-visitant category, which have bred and raised broods during April, May and 
" Jinie. Such as Bullock Oriole, Yellow Warbler, l,azuli Bunting, Parkman Wren, Black- 
" headed Grosbeak and many others become scarce, or disappear altogether, towards 
" the end of July. Even resident .species.. .. California Bushtit and Jay, Black Phoebe, Auiia 
" Humming-bird, and others, are reduced in numbers, although they appear again in early 
" winter. The reason for the summer exodus is plain July to October constitute the 
" winter season at the lower altitudes of Southern California as far as the food supply is 
" concerned the May bird population, whicli is abundant cannot continue to be sup- 
" ported after this winter season sets in, and the result is, they must move elsewhere 
" where do our birds go? many species which bred far below u.s are now (August) moving 
" up the mountains Black-headed Grosbeaks, Bushtits, Western Guatcatchers, Wrens, 
" Warblers, are moving up along the Santa Ana, where a montli ago none of these species 
" were to be seen All this influx of population appears to be mainly due to the con- 
" spicuous abundance of both vegetable and insect food, particularly the latter 
" Normally seed-eating birds are taking advantage of this supply, and such species as the 
" Western Chipping sparrows and Lazuli Bunting are seen carrying larvae to their full- 
" grown but teasing offspring All this invasion of the higher altitudes occurs when 
" spring and sunnner are jnst dawning there, but when the foothills and plains below are 
" become dry and barren under the July heat." 
