Mating season or mating cycle was a time of the year during which members of a certain species of animal would tend to mate. For some species this was best accomplished in a pre-selected breeding ground.
In 2151, Jeremy Lucas was living on Denobula during the Denobulan mating season. In a communication to Denobulan Dr. Phlox aboard Enterprise NX-01 that year, he explained that upon experiencing it, and although believing that "Human reproduction was complicated," he felt "you Denobulans make us look like single-celled organisms." In Phlox' reply, he explained that he knew "the rigors of mating season only too well," advising that "it might help to bear in mind that a dose of niaxilin can be quite effective in separating the two combatants." (ENT: "Dear Doctor")
In 2370, Gul Evek told Miles O'Brien that the Cardassian voles' mating season would begin in about six weeks. (DS9: "Playing God")