The Cornell Lab Bird Academy › Discussion Groups › Bird Identification › Acerca de Cathartes aura, como podemos diferenciar machos de hembras?
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Observando la topografía anatómica es posible diferenciar machos de hembras?, la bibliografía dice las hembras son ligeramente mas grandes que los machos.You must be logged in to reply to this topic.
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I believe that this is a female rose breasted grossbeak. but I have not seen the golden marking on one of these birds before. I am wondering. Is this unusual or more common than I think.
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It is a rose breasted grosbeak. It has the same markings, although the breast is a mystery.
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The yellow breast (and underwing coverts), it turns out, are the result of a condition called xanthochroism. Just like albinism is a lack of pigment, and melanism is an excess of pigment, xanthochroism is an abundance of yellow pigment. It may be caused by certain abnormal items in the diet or dietary deficiencies, or may be genetic. The yellow may either be present in excess, or it may replace another colour (usually red, which is often itself controlled by diet). i got this online. pretty cool huh?!
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Sí, y es cierto. Esa es la única manera de identificarlos realmente.