I have a good book about reptiles that has an extensive section on whiptail lizards and a chart with which species have males, I believe that the western whiptail does not, but i am not sure I'll have to look at it when I go back home. The book is "Reptiles & Amphibians of New Mexico" It is an amazing resource!
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1.1 Rosy Boa
0.1 Mexican Rosy Boa
1.0 Coastal Carpet Python
1.0 Miniature Daschund

