Members of the genus Canis have reproductive cycles with several unusual features: monogamy, parental care, monestrus, extended proestrus and diestrus stages, a copulatory lock, incorporation of offspring into the social group, social suppression that keeps subordinates from breeding, obligate pseudopregnancy in subordinate females, and helping behavior by group members including males. I define and discuss these concepts here and in the next chapter, demonstrating how their intricate patterns of timing affect societies of wolves and free-ranging dogs.

Aspects of the reproductive cycles themselves differ in degree but not kind. Most changes are endocrinological and therefore invisible, yet they profoundly affect social behaviors and interactions. To ignore their details in favor of strictly observational information puts aside the biological basis of reproductive behavior, revealing only a partial glimpse of its integrated functions. In addition to the expected differences between wolves and dogs are large individual variations in endocrinological profiles throughout the reproductive cycle, and these are routinely evident even in littermates. I start with an explanation of how the endocrinological factors cycle, stitching in brief mention of the external displays we recognize as courtship. Aspects of courtship in owned dogs, wolves, and free-ranging dogs are then discussed specifically.