Grizzly bear cubs are born in the den in January or Febuary. The cubs will weigh approximately 500 grams ( 1 ½ pound) at birth, and arrive into the world blind, hairless, and toothless. The cubs will grow to weigh 3-4 kg (7-9 lbs.) prior to emerging from the den in spring. This photo was taken in early September so these first year cubs are six or seven months old. As you can see from the photo that this mother grizzly is still nursing. The milk from a grizzly is rich in fat, approximately 30% compared to a cow at 3% so these cubs will weight 27 – 45 kg. (60 to 100 pounds). Also the photo shows the difference in size in the three cubs the one being much larger. This is common and shows which of these cubs has a better chance of survival.