Definition: 1) Producing live offspring from within the body of the parent (Lincoln et al., 1998). 2) Development of an embryo within the body of the parent, in part, resources passing directly from parent to embryo (Barnes et al., 2006).
Definition: a pair bond between two adult animals of the same species – typically of the opposite sex. This pair may cohabitate in an area or territory for some duration of time, and in some cases may copulate and reproduce with only each other. Monogamy may either be short-term, lasting one to a few seasons or long-term, lasting many seasons and in extreme cases, life-long.