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Thickness of 1967-69 whooping crane eggshells compared to that of pre-1910 specimens

The Auk

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https://doi.org/10.2307/4083896

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Abstract

Table 1 summarizes measurements of pre-1910 Whooping Crane (Grus americana) eggshells obtained from 10 North American museums and private egg collections. They include 30 eggs from Iowa, 5 from North Dakota, 13 from Manitoba, and 2 each from Saskatchewan and Alberta; 11 of the eggs were classified as subelliptical and 41 as oval according to the shapes described by Palmer (1962: 13). Mean clutch size of 29 sets averaged 1.83. We found no significant geographical variations (P < 0.20) among eggs from different portions of the former range (Allen, 1952: 19) of the Whooping Crane, although geographical variations in size and weight are known to occur in the eggshells of the Sandhill Cranes (G. canadensis), which are more widely distributed and more taxonomically diverse (Walkinshaw, 1949: 68-70). The average thickness and weight of the 52 eggshells were 0.60 mm and 20.1 g, respectively. These measurements are similar to those of Allen (1952: 180), citing M. Schonwetter, who gives the average thickness of Whooping Crane eggshells as 0.58 mm and the average shell weight as 20.75 g (n = 14 weights).

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Thickness of 1967-69 whooping crane eggshells compared to that of pre-1910 specimens
Series title:
The Auk
DOI:
10.2307/4083896
Volume:
88
Issue:
2
Year Published:
1971
Language:
English
Publisher:
American Ornithological Society
Contributing office(s):
Patuxent Wildlife Research Center
Description:
2 p.
First page:
433
Last page:
434