This poem seems to explore both the ways in which human beings are similar to animals as well as the ways in which they are quite different from them. For example, in the poem's second section, the speaker describes the steps he takes to fatally wound the bear, making it easier to track as well as ensuring its eventual demise. He says,

I take a wolf's rib and whittle
it sharp at both ends
and coil it up
and freeze it in blubber and place it out
on the fairway of the bears.

Here, Kinnell demonstrates the steps and the thought-process of the narrator, and readers must recognize that these are steps and processes that would be closed off to the bear. The speaker sharpens a wolf's rib and hides it within something he knows the bear will eat, and in this way he can wound the bear significantly enough to kill it. Other animals could not think to employ such sophisticated methods, and even if they could, most would lack the necessary tools with which to accomplish the task.

The speaker begins to starve during the hunt, and he finds

. . . a turd sopped in blood,
and hesitate[s], and pick[s] it up,
and thrust[s] it in [his] mouth, and gnash[es] it down

This is an incredibly animalistic thing to do. There are many animals that do this: some breeds of dogs, rabbits, rodents, hippopotamuses, even primates. It's a way for these animals to have a second try at digesting nutrients that they could not during the first digestion of the food. Eating the bear's feces, then, is the speaker's way of trying to gain more access to its lived experience.

Finally, when the speaker locates the bear's body, he hacks into it, drinking its blood, and then he

. . . tear[s] him down his whole length
and open[s] him and climb[s] in
and close[s] him up after [the speaker], against the wind,
and sleep[s].

He attempts to actually inhabit the body of the bear by opening it up and crawling inside of it. He dreams of walking around in the bear's body, of living on the tundra, even of how the bear would have felt as it was stabbed from within by the wolf's rib. He feels the life force of the bear diminishing, the result of the weapon fashioned by himself, even as its body tries to digest the bone and belches blood. He can only wrap himself in the bear's life, however, limited to dreaming it rather than actually experiencing it—though this still seems to appeal to some vital, animal part of the speaker's own nature.