Reviews

Geographic variation in the White-crowned Sparrow Zonotrichia !eucophrys.--Richard C. Banks.1964.Univ. of California Publs.Zoi51., 70: 1-123, 28 figs., 43 tables.$2.50.--Thisstudy is based on an examination of 2,103 breedingseason specimens representing 62 populations and groups of populations in various parts of the range.Mensural characters examined include length of wing, tail, bill, and tarsus; also tarsus/wing ratio and, when available, weight.These are thoroughly analyzed and samples of more than nine individuals are given elahorate statistical treatment.The results are interpreted in detail, and, in the course of this, effective use is made of numerous tables and figures.Both interpopulational and intrapopulational variations are investigated.The examination of color characters is less thorough.Emphasis is on variation in rump coloration, segregated into seven categories.Color of the lores and the bend of the wing receive careful attention also.Variations in the colors of the striped upper back, fully as important as those of the rump, receive much less detailed treatment.Variation in colors of the under parts, which is of greater taxonomic significance than seems to be generally realized, was not investigated at all!The reviewer believes that examination of a wider range of color characters would probably have lent weight to some of the author's conclusions and might well have modified others.The author finds the two Pacific coast subspecies Z. I. pugetensis and Z. I. nuttalli valid, but weakly separable from each other by size, chiefly the longer tarsus of nuttalli.Color differences between the two are considered unreliable due to differential feather wear, which the author attributes to a less extensive prenuptial molt in nuttalli.A comparison of freshly-molted specimens of the two races might have shed additional light on this question, but unfortunately this does not seem to have been done.These two similar races differ from the other subspecies in possessing shorter wings, darker upper parts, and yellow (instead of white) coloration at the bend of the wing.In the vast remainder of the range the author recognizes only two subspecies: Z. I. gambelii (Alaska and most of western Canada) and the nominate race (eastern Canada east of James and Hudson hays, the western mountains of the United States, and the Cypress Hills of Canada).There is a broad area of intergradation in the Hudson and James bays region, and also in northwestern Montana and contiguous mountainous parts of Canada.The most reliable distinguishing mark separating these races is still the traditional one, the presence of a black interruption in the white superciliary stripe at the anterior corner of the eye (nominate race) versus the lack of such a black interruption (gambelii).Various degrees of intermediacy occur.Surprisingly, Banks concludes that the black-lored birds of the mountains of western United States and the Cypress Hills of Canada (Z. l. oriantha) are not satisfactorily separable from the b!ack-lored birds of eastern Canada, and he therefore relegates oriantha to the synonymy of the nominate race.It seems regrettable that he apparently did not investigate the useful color characters of the under parts or examine in more detail those of the upper back.Re-examination of material in the National Museum of Canada leaves no doubt in this reviewer's mind that, contrary to Banks, oriantha is a valid subspecies, separable from eastern black-lored birds by its paler upper back and lighter under parts (breast markedly paler gray; flanks and under tail coverts duller buff).

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.