Ruffed grouse, white-tailed deer and moose, all prey species and all plant eaters, share certain characteristics that have to do with food consumption and digestion. They all tend to eat large quantities rather quickly in one spot, and then move to another, safer, spot to digest their food. This technique minimizes the amount of time that they are likely to be out in the open and focused more on eating than on predators. Eating quickly and storing the consumed food in a chamber and digesting it later at their leisure, under cover, makes a lot of sense.
All three animals have a multi-chambered stomach and microorganisms efficient at breaking down cellulose and extracting nutrients from plants. After browsing on branches and buds, deer and moose seek shelter where they then regurgitate and chew their cud. Grouse do not linger over their meals – 20 minutes of foraging will sustain them all day. Leaves, buds and twigs are stored in their crop (a wide portion of the esophagus) until the grouse seeks shelter, where the food eventually reaches their gizzard. Here, with the aid of gravel, it is ground up.