The rut of the northern subspecies is in November and December. The males then cry with high notes which often change into piercing sounds. The females' gestation period is seven and a half months, and the young are born by the end of June to the beginning of August. Usually only one young is born, although twins occur on occasion. The life span of the sika is 10-15 years.
Sika deer are amazingly hardy.
They thrive even in winter on scarce food without additional feeding. Sikas are highly vocal. At least ten different sounds have been recorded. These deer are easy to tame and thus they are popular game park animals in many places. Tame sika deer are kept in several temple regions of Japan, and people come to visit them and offer them rice cookies for food.