American black bears can grow from 5 to 6 feet in height and weigh up to 600 pounds _ although in New Jersey females average 185 pounds and males about 400. Males can range up to 60 square miles from their home; females generally stay within a 10-mile radius. Life span is generally about 10 years in the wild; can be more than 20 years in captivity. Sexual maturity is reached around age 3, although only the strongest and most assertive males win the competition for mates. Females usually have litters every other year, four or five times during their lives. Breeding season runs from late May to August, peaking in June and July. Females ovulate only upon mating, but even if that egg is fertilized, an embryo will not implant itself in her uterus until November or December. Gestation takes about two months. Newborns usually weigh no more than 8 ounces, are blind and almost hairless. Litters can range from one to six cubs, depending on how much nourishment the mother has gotten. Cubs travel with their mother for up to 18 months, until she breeds again.