| Abstract: | A collection of 98 breeding Mexican Ducks (Anas platyrhynchos diazi) was made in Mexico from six areas between the United States border with Chihuahua and Lake Chapala, Jalisco, in order to study geographic variation. Plumage indices showed a relatively smooth clinal change from north to south; northern populations were most influenced by the Northern Mallard (A. platyrhynchos) phenotype. Measurements of total, wing, and culmen lengths and bill width were usually significantly larger in males at any one site, but showed no regular geographic trends. Hybridization between platyrhynchos and diazi phenotypes may or may not be increasing in the middle Rio Grande and Rio Conchos valleys; available data are insufficient to decide. A spring 1978 aerial census yielded an estimate of 55,500 diazi -like birds in Mexico. Populations of diazi appear to be as large as the available habitat allows; management should be directed towards increasing and stabilizing the nesting habitat; and the stability of the zone of intergradation should be investigated. |
| Genre: | Article |
| ProdID: | 5223752 |
| Citation Author: | Scott, N.J., Jr.; Reynolds, R.P. |
| Citation Contributing Office: | Patuxent Wildlife Research Center |
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| Citation End Page: | 274 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Condor |
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| Citation Number Of Pages: | 9 |
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| Citation Phsyical Description: | 266-274 |
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| Citation Search Results Text: | Phenotypic variation of the Mexican duck (Anas platyrhynchos diazi) in Mexico; 1984; Article; Journal; Condor; Scott, N.J., Jr.; Reynolds, R.P. |
| Citation Start Page: | 266 |
| Citation Volume: | 86 |
| Citation Year: | 1984 |
| Type: | citation/reference |
| Text: | Phenotypic variation of the Mexican duck (Anas platyrhynchos diazi) in Mexico; 1984; Article; Journal; Condor; Scott, N.J., Jr.; Reynolds, R.P. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DOCUMENT): | http://elibrary.unm.edu/sora/Condor/files/issues/v086n03/p0266-p0274.pdf |
| Date Other: | Wed, 16 Jun 2010 12:19 -0500 |
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