The North American Whistling-Ducks, Pochards, and Stifftails by Paul Johnsgard (
28,69 €
In contrast, males of the five typical pochards (Aythya) maintain monogamous pair-bonds only long enough to assure that the female's eggs are fertilized. Such diverse reproductive strategies have exerted powerful evolutionary influences on interspecies variations in sexual dimorphism, sexual behavior, anatomy, ecology, and other traits.
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