I just returned from a backpacking trip in the Bighorn Mountains of Wyoming (where I saw some interesting high-elevation birds), but one of the stranger sights was an American Robin we saw hopping along the trail in front of us who seemed to be struggling with a large prey item. We stopped to watch as the bird put his prey on the ground and pecked at it.my initial thought was "wow, that must be a really huge caterpillar." Then I got a good look through binoculars and discovered Mr. Robin had himself a small mouse or shrew.a little gray animal with four little paws and a long tail. Has anyone seen this behavior before? Would a robin kill a rodent, or just be lucky enough to happen upon one that was already dead?