Nature Notes

Franklin's Ground Squirrel


There are a large number of mammals that call the tall grass prairies and oak savannas of Northwest Indiana home. Many of these mammals are considered generalist. These are species that have wide ranges both geographically and ecologically. White-tailed deer are found everywhere, from forests to prairies to cities. Coyotes, rabbits, fox, beaver? Those are found all over too! But, the tall grass prairie is such a unique ecosystem, and there must be some mammals that need our specific combination of traits, just like our grassland birds, insects, reptiles, and amphibians. Of course there are, and one of those species is the Indiana state endangered Franklin’s ground squirrel. 

Franklin’s ground squirrel (Spermophilus franklinii) is a grassland mammal that inhabits areas with tall dense herbaceous cover. Unlike their much more common relatives, the thirteen lined ground squirrel, Franklins do not often utilize edges, right-of-ways, and area with shorter cover, such as grazed, mowed, or sparsely vegetated areas. This is one of the major reasons the Franklin’s ground squirrel is endangered. With nearly all (99%) of the tall grass prairie gone, degraded, and converted into agriculture and urbanization; as a species that requires a healthy intact habitat, they simply have nowhere to live.

Named for Sir John Franklin, an explorer who died searching for the Northwest Passage, the Franklin’s ground squirrel resembles the much larger common gray squirrel. However, as compared to the gray squirrel, Franklin’s have a shorter, less bushy tail and smaller ears. They also resemble the thirteen-lined ground squirrel, but are larger and do not have those lines. All three of these squirrels prefer different habitats.

Franklin’s ground squirrels are grayish brown with slightly molted look that can at times resemble light spotting or bars. White hairs are often found at the tip of their tales and encircling their eyes. Often their bellies are a lighter color, a bit more yellowish. There is also a bit of variation in the darkness of their fur from the time their born through adulthood. Young are generally darker. They are between 12-16 inches long, including their tails, which are between 4-6 inches. Males are larger than females and can weigh up to 1.8 lbs., though more typically they are between 12-17 oz.

Although considered omnivorous, the bulk of the Franklin’s ground squirrel’s diet consist of green vegetation, seeds, and fruits. They do eat many kinds of insects, including beetles and grasshopper as well as the occasional small vertebrate and eggs. Some reports say they have been seen to occasionally feast on carrion along roads.

Reports on their social structure are conflicting. Some believe that they are mostly asocial with overlapping home ranges, but mostly keeping to themselves. However, there are many reports of Franklin’s ground squirrels living in colonies, commonly association of 10 or more, but some known colonies consist of 50-100 individuals. Since they are so rare and the majority of their time is spent underground, it may be difficult to truly understand their social interactions.

I have never seen a Franklin’s ground squirrel, and it is very unlikely that there are some currently living on the Kankakee Sands Restoration. I am, however, always on the look-out for these adorable little critters. If there is a colony here, it is more likely that I will hear them chirping away or notice their homes (3-4 inch holes with small mounds in front of them) than actually see one. Who knows, maybe someday they will make their way back home!