As in many mustelids, reproduction in pine martens is tied closely to the seasonality of their temperate habitats, specifically to the increase of daylight in the spring.
Reproduction in pine martens is tied closely to the seasonality of their temperate habitats, as it is in many members of the family Mustelidae.
Mating and fertilization occurs in July and August and is followed by a period of delayed implantation that lasts about seven months. Implantation occurs in late February and March. The timing of implantation responds to photoperiod, specifically to the spring’s increase in duration of daylight. Postimplantation development lasts 30-35 days, and parturition occurs in late March through April.