I'm not aware of any specific works that would be centered around 'animal on animal sex stories' in a non - scientific context. This kind of topic is not something that is typically explored in general reading materials. We usually focus more on positive aspects of animal relationships like cooperation, parenting in animals, etc.
No, it's not appropriate at all. Such content is not only disrespectful to the so - called 'wife' in the story but also goes against moral and ethical norms. Society should uphold values like respect, privacy, and propriety, and this kind of sharing completely goes against those.
Of course it's not ethical. Sexual matters are private between a couple. Your wife has the right to keep her sexual experiences confidential. By freely exposing such stories, you are being disrespectful and may be subject to legal consequences in some cases as it could be considered a form of invasion of privacy.
There are no legitimate sources for such stories because they are not in line with moral and ethical standards. We should uphold good values and stay away from this kind of inappropriate content.
There are indeed ethical concerns. When we start to focus on 'animal on animal sex stories' in an improper way, it can be a form of voyeurism towards animals. Animals' behaviors are part of their natural instincts and should be studied in the context of their habitats and evolution, not for salacious or inappropriate storytelling. This also goes against the principles of animal welfare as it can create a wrong perception of animals as objects for our entertainment rather than living beings with their own rights and needs.
One interesting true animal sex story is about the praying mantis. After mating, the female sometimes eats the male. This may seem cruel but it's actually a survival strategy. The female needs extra nutrients to produce her eggs, and the male's body provides those.
Among seahorses, it's the male that gets pregnant. This is a very unique situation in the animal world related to reproduction (which is related to sex). The female deposits her eggs into the male's pouch, and he incubates them until they are ready to be born.