Charles Darwin University

CDU eSpace
Institutional Repository

 
CDU Staff and Student only
 

Boofheads with deep voices: sexual dimorphism in the Magpie Goose Anseranas semipalmata

Whitehead, Peter J. (1998). Boofheads with deep voices: sexual dimorphism in the Magpie Goose Anseranas semipalmata. Wildfowl,49:72-91.

Document type: Journal Article
Citation counts: Scopus Citation Count Cited 2 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Attached Files (Some files may be inaccessible until you login with your CDU eSpace credentials)
Name Description MIMEType Size Downloads
Download this reading Whitehead_260.pdf Published version application/pdf 9.59MB 67
Reading the attached file works best in Firefox, Chrome and IE 9 or later.

Title Boofheads with deep voices: sexual dimorphism in the Magpie Goose Anseranas semipalmata
Author Whitehead, Peter J.
Journal Name Wildfowl
Publication Date 1998
Volume Number 49
ISSN 0954-6324   (check CDU catalogue open catalogue search in new window)
Scopus ID 2-s2.0-0032412215
Start Page 72
End Page 91
Total Pages 20
Place of Publication United Kingdom
Publisher Wildfowl and Wetlands Trust
HERDC Category C1 - Journal Article (DEST)
Abstract Magpie geese use a unique polygynous mating system, involving apparently stable trios of one male and two females. Plumage shows little sexual differentiation, but there is considerable dimorphism in body size, with males being about 30% heavier. The males also develop an extraordinarily elongated and elaborately folded trachea early in life, whereas less than 85% of females show even minor tracheal elaboration. Head height, a measure of the size of a cranial bump of spongy bone increases with age in both sexes, but most markedly in males. Males found in association with nests have larger bumps and highly elaborated tracheal morphology. The deeper and louder calls associated with gross tracheal elongation, which probably comprises respiratory exchange, may influence female choice of mates by providing a reliable signal of male viability. Despite significant overlap in individual dimensions, especially among younger birds, more than 92% can be accurately sexed using a discriminant function based on three simple measures (head-bill length, head height, and tarsus length). Discrimination can be improved by checking birds assigned as females against an index of tracheal morphology. Simulations indicate that bias in estimates of sex ratios arising from application of the discriminant function, when combined with tracheal examination, is likely to be less than 2%.


Keywords Magpie Goose Anseranas semipalmata
Description for Link Link to published version
URL http://wildfowl.wwt.org.uk/index.php/wildfowl/article/view/1040


© copyright

Every reasonable effort has been made to ensure that permission has been obtained for items included in CDU eSpace. If you believe that your rights have been infringed by this repository, please contact digitisation@cdu.edu.au.

 
Versions
Version Filter Type
Access Statistics: 95 Abstract Views, 68 File Downloads  -  Detailed Statistics
Created: Fri, 12 Sep 2008, 08:35:25 CST by Administrator