[ChrisBennet]

The mating behavior of animals is amoral and of no relevance to (moral) human mating behavior. You may find sentimental similarities between animals and human behavior (mating for life touches our heart strings for example) but you won't find moral relevance.

In nature, animals tend to be monogamous if it will increase the chances of their DNA being passed on (historically and statistically speaking). For example, in the case of animals that that have "expensive to to raise" young, sticking around to raise them may increase the chances of the father's genes being passed on more than spreading his genes among multiple females.

In the case of humans, a single female can raise a child to reproductive age by herself so the "natural" thing would be to impregnate as many females as possible.

-Chris

P.S. Isn't this sort of thing common knowledge?