Grizzly bears nursing
Grizzly bear cubs begin nursing when they are born in their mother's den during hibernation. Newborn cubs will usually nurse for less than 10 minutes every two to three hours. Grizzly cubs will continue to nurse for the next two to three years, depending on when their mother decides to wean them. Grizzly bear milk is roughly 30% fat. From an early age, grizzly cubs also eat solid food. During the summer in Hallo Bay, many cubs alternate between nursing, grazing on sedge grass and other vegetation, and eating clams and salmon procurred by their mother.
It is impossible not to notice when grizzly cubs are hungry. Wishing to nurse, grizzly cubs will begin to whine, which is a surprisingly loud type of howl or growl. The first time I heard this noise, I actually thought it was the mother since the call was so loud, deep and forceful. When hungry, cubs will pursue their mother screaming their heads off to demand milk. (You can listen to this noise in our nursing video).
When grizzly cubs are actually nursing they make a loud purring noise, sometimes called a "nursing chuckle". I think it sounds more like a loud, rhythmic fluttering noise than the purring you might associate with a cat. Like the fluttering of a thousand tiny wings, this is one of the most beautiful noises in the world. The noise is thought to encourage the mother to release milk. Cubs switch nipples often during nursing, and young cubs will also kneed the nipples with their paws to stimulate the flow of milk. Usually after nursing both mother and cubs will settle in for a long nap.
Mother grizzly bears nurse in a variety of positions, but most often they are either sitting up, or reclined onto their backs with their heads raised. While lying on their backs, most mothers keep their heads raised to remain vigilant, scanning left and right every minute or so. This photo shows a third year cub (Racer) who is still nursing. Watching huge, third year cubs nurse always makes me laugh because they look like the world's biggest "babies".
Female grizzly bears have six nipples. Two sets of nipples are located on her upper chest where these two cubs above are nursing. Female bears also have a set of nipples in their groin area.
This photo of a standing female grizzly bear clearly shows the four nipples on her upper chest. Her two groin nipples are not visible. The placement of the nipples - with a large space between the chest and groin nipples, facilitates nursing when a mother grizzly bear is curled up in her den. If she had nipples in the center of her chest they would get lost in the folds of her curled up body while in the winter den.
© 2008 Jessica Teel