The definition of monogamy is a hard one to pin down. In one famous study of blackbirds, females matched up with sterilized males were suspiciously still laying eggs that hatched.
Scientists break down monogamy in the animal kingdom into three categories:
1. Sexual monogamy: The practice of having sex only with one mate at a time.
2. Social monogamy: When animals form pairs to mate and raise offspring but still have flings -- or "extra-pair copulations" in science lingo -- on the side.
3. Genetic monogamy: When DNA tests can confirm that a female's offspring were sired by only one father.
Wolves are considered serial monogamous. This category also includes the largest rodent in North America: beavers.
Both mother and father beaver have strong essential roles in the family unit. Damns and pools must be maintained, and families can be big -- two to four kits or more which must be raised for two years.
Yep, that's a mouthful of big teeth, but beavers are actually vegetarians.
Photo via caprilis.wordpress.com