A bear’s hands and feet have many similarities to our own. The feet of both bears and people are much longer than wide. (The length to width ratio of the feet averages about 10:5 for blackies, 10:6 for grizzly/brown bears, and 10:7.5 for polar bears. The L/W ratio for hands averages around 10:11 for both blackies and grizzly/brown bears, contrasted to 10:16 for polar bears. The added width of a polar bear’s feet and hands increases their utility as snowshoes and (hands only) as paddles for swimming. Bear and human feet are also alike in having a heel, ball, and five toes. A bear’s hand is structurally halfway between a person’s foot and a person’s hand. A bear’s hand has a ball; its five ‘fingers’ are joined with a thick web except at the bottom of the finger pads – each of which is similar to a bear or human toe. Sometimes, the only parts of the hand that leave an imprint are the ball and finger-pads. HANDS      Figure 11:1. Right hand of a North American black bear, and the track it makes.   Ursine pseudo-thumbs. All North American bears have thick pads on their fingertips and palms, as well as one at the tip of their pseudo-thumb, which lies on the outer (ulnar) side of the hand.  This outer pseudo-thumb of all bears should not be confused with the inner (radial) pseudo-thumb found only in the Panda.   Manipulating and Gripping Objects Bears use their claws to grasp food and other small objects. Some objects are squeezed between two adjacent claws. Sticks are sometimes grasped by placing 1 or 2 claws over the stick and 2 or 3 under it. The claws may be used to rake berries or other fruit off stems and branches into the mouth, to peal the skin or meat of a fish away from its bones, to open a clam, or to open a dead mammal to reach its viscera. Claws are also used by a cub to hold onto the mother when riding on her back -- a mode of travel that I have seen in all three North American bears on occasion, but which seems common only in the sloth bear. In that species, griping is assisted by the ability to fold the palm sideways (like a baseball mitt) -- which is how I have seen a captive sloth bear hold an ice cream cone while eating it. Gripping objects is also facilitated by an elongated bone on the outside (ulnar side) of the wrist -- just below the first “finger”, which in apes and humans has been modified into an opposable thumb. This ulnar wrist bone acts in opposition to the five “fingers” of a bear’s hand, but is not mobile. It is sometimes called a “pseudothumb”  Figure 11:2. Hands and feet of 3 bear species The hands of a panda bear are further adapted for grasping objects by the presence of a second opposable elongated sesamoid, wrist bone, this one on the inside (radial side) of the wrist. Unlike the ulnar bone, the radial one is mobile, functioning somewhat like a human theumb. More than any other single trait, this pseudothumb has seemed unique to the giant panda, separating it from other bears (Fig. 8:2). The pair of opposable wrist bones, operating in opposition to the five fingers, gives the panda a uniquely good grip on “sticks” like bamboo stems. (Davis 1964) .  Figure 11:3. Right hand of a panda (palm view) Contrast it to that of a black bear (Figure 11.4)  Figure 11:4. Black bear right hands, with and without phlanges -- which are covered with claws. Note that even a black bear has slight elongation of the radial wrist bone, although it is smaller and much less mobile than a panda’s. Although the phlanges of a human or ape differ from a bear’s by lacking claws, the metacarpals of bears, humans and apes are very similar (Figure 8.4). (these bear hand bones and the human hand and foot bones are replicas which can be purchased at boneclones.com)   Figure 11:5 Human bear right hands. (www.boneclones.com) Standing and Gripping Logs or Other Substrates The elongated ulnar wrist bone helps bears to grip branches and logs much more tightly than would otherwise be possible – which is why a bear can walk across a narrow limb or log without falling, more easily than can other large mammals or people. Positioning the hand so that the ulnar wrist bone can help grip a branch or log requires turning the hand inwards -- a so-called pigeon-toed gait. By contrast, an elongated radial wrist bone might get in the way.  How pandas cope with this is unknown. The pad of the ulnar pseudo-thumb often fails to show up in a bear’s tracks, as may the fifth and smallest finger.                                                                      Figure 11:6. Use of the ulnar pseudo-thumb by a black bear for gripping a log on which it is standing. This analogous to how a the heel of a person’s hand might be used.     FEET  Figure 8.5. Human right feet. (www.boneclones.com) 
 CLAWS For information on how claw structure and size varies among bear species, contrasted with other mammals, click here  http://www.boneclones.com11b%20Claws.htmlshapeimage_3_link_0
Chapter 11.  HANDS, FEET & CLAWS
Radial
Ulnar
Ulnar
Radial
Ulnar
Radial