An Ornithological Comparison of the Pajaro Valley in California with Sioux County in Nebraska

J. S. Hunter
1904 The Condor  
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more » ... out Early Journal Content at http://about.jstor.org/participate--jstor/individuals/early-journal--content. JSTOR is a digital library of academic journals, books, and primary source objects. JSTOR helps people discover, use, and build upon a wide range of content through a powerful research and teaching platform, and preserves this content for future generations. JSTOR is part of ITHAKA, a not--for--profit organization that also includes Ithaka S+R and Portico. For more information about JSTOR, please contact support@jstor.org. 168 THE CONDOR VoL. VI ional. I am quite able to agree with him, for in the large series that I have referred to I have found only twenty-two eggs that measured 3.10 or more in length, and of those, fifteen exceeded 3.15, four of these going beyond 3.20 inches. From these data the mammoth proportions of my eggs may perhaps be better appreciated. They measure 3.47 by 2.62, and 3.37 by 2.64 inches. Plain figures, while doubtless plain facts, are less readily digested than a more tangible object lesson, so I have included in a photograph for comparison, a large egg of a western red-tailed hawk, measuring 2.52 by 2.00, an average golden eagle's egg measuring 2.97 by 2.23, and the larger of my large set measuring 3.47 by 2.62. From the photograph and measurements, it will be seen that the large eagle's egg is as much larger than the average as that is larger than a red-tail's egg. In coloration, as appears in the photograph, the larger egg is the more lightly marked. The markings appear more as ingrained shell markings of faint lavender and umber, giving the egg the appearance of having a very dirty white ground color. There are a few superficial spots and small sp-lashes of a (larker sh'ide. The smaller egg is very handsome, the markings being of a much brighter tint, making the ground appear brighter and clearer by contrast. As shown in the photograph, the markings are heavier at the small end. At the large end the markings are all nearly confluent but very faint in shade, and have more the appearance of shell markings. The intermnediate blotches and splash-1s aIre very bright. In both eggs the shell is very smooth, with few granulations. Incubation had just commenced and was equal in both eggs. One naturally wonders why there should be so much difference between these eggs and others taken from the same nests and presumably the product of the same birds. A set of two taken from a "series of five" nests occupied by this pair of birds, are about average eggs, measuring 2.97 by 2.23 and 2.93 by 2.24 inches. The larger is the central egg in the photograph. The markings are strongly defined blotches and spots of a dark reddish brown and almost wholly at the larger end, no lavendershade appearing anywhere. T'he other egg is absolutely unmarked. The "Spook" Canyon bird was unusually dark seeming almost black, and very large-in fact the largest and blackest eagle I ever saw, and in perfect plumage. I had a good view of her when she left the nest for I was not five feet from her. Then after I had left the nest and was on the ground below not more than fifty feet away she did what no eagle of my acquaintance ever did before, came back to the nest and settled down on it again with head up watching me and making a curious clucking, like the common call of the Cooper hawk, which she repeated a dozen times.
doi:10.2307/1361515 fatcat:mbdnpx32vvfztfcesqxagbhud4