Avian sex

Sure, birds can fly, but how do they have sex? Can they do it in the air? And where do they keep their reproductive organs? For humans to understand bird sex, they must first throw out all thoughts of mammalian sex organs. Unlike mammals, most male birds don't have penises.
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Avian sex determination: what, when and where?

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Avian sex, sex chromosomes, and dosage compensation in the age of genomics.

Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. A Nature Research Journal. Hormones are not all-powerful in determining whether birds develop with male or female features.
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Q & A; Avian Intercourse

Parents have supposedly explained human reproduction to children in terms of the birds and the bees; if birds were really used to make this explanation, it would be widely believed that fertilization occurs after the briefest period of proximity of the waste elimination organs. Most birds do not have external sex organs, according to ''Ornithology,'' a manual by Frank B. Gill W. The transfer of sperm from male to female usually takes place while the male bird is standing or treading on the female's back.
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The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds , some fish and crustaceans such as the giant river prawn , some insects including butterflies and moths , and some reptiles, including Komodo dragons. The letters Z and W are used to distinguish this system from the XY sex-determination system. In this system, female has a pair of dissimilar ZW chromosomes and male has two similar ZZ chromosomes. In contrast to the XY sex-determination system and the X0 sex-determination system , where the sperm determines the sex, in the ZW system, the ovum determines the sex of the offspring. Males are the homogametic sex ZZ , while females are the heterogametic sex ZW.
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