White-tailed deer live on the sanctuary and in the surrounding open space parcels throughout the year. They can often be seen grazing in the back fields at sunrise. Coyotes, red fox and gray fox prey on mice and voles on the sanctuary, and are visible during daylight hours from time to time. fishers, short-tailed weasels, gray squirrels, red squirrels, field mice, and meadow voles have been seen on the sanctuary trails. Northern river otters occasionally appear in the Green Harbor River.