Spermophilus franklinii
Franklin’s Ground Squirrel
Written by Kristen Cragin, Biology 378 student, Fall 2003
Classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Suborder: Sciurognathi
Family: Sciuridae
Subfamily: Sciurinae
Genus: Spermophilus
Species: franklinii
Table of Contents
Geographic Range
Physical Characteristics
Natural History
Life Cycle
Reproduction
Habitat
Food Habits
Ecology
Behavior
Remarks
Literature Cited
Geographic Range
Nearctic: Franklin’s ground squirrels range
in distribution east to Indiana and Illinois,
west to North Dakota and Kansas and as far
north as southern Ontario and central
Manitoba and Alberta. In Wisconsin they
cover one half of the state at a diagonal from
the north at Superior and south to Racine
(Lewis & Rongstad 1992).
Physical
Characteristics
Except for the prominent white eye-ring,
Franklin’s ground squirrels
resemble Eastern gray squirrels at a distance
(Wilson & Ruff, 1999). They have a gray
head that grades into a brown color with
indistinct buff and black barring. The chest
and belly are buffy-white to gray and the
tail is gray like the head. They have a
slender and elongated body that measures
350-420mm (14-17in). They have a shorter
and less bushy tail than the gray squirrel,
measuring 125- 160mm (4.9-6.3 in), which
accounts for less than 40% of their total
length. They have smaller and more
rounded ears than a gray squirrel measuring
16-18mm (0.6-0.7in) in height and
weighing 370-500g (13.1-17.6 oz). This
includes average emergent weights of 410g
for males and 351g for females. (Kurta, 1994; Sowls, 1948).
Natural History
Life Cycle and Reproduction
Franklin ground squirrel populations peak every four to six years due to fluctuations in
climatic extremes, infertility, and disease (Sowls, 1948).
Erlien and Tester (1984), also attribute this cycle to a possible correlation between
Snowshoe hare cycles, with a time-lagging decline of Franklin’s ground squirrel
populations corresponding to increases in hare populations.
The Franklin’s ground squirrel spends 7-8 months, from mid to late August through
April, hibernating in an underground burrow each year. Males emerge first and mating
occurs soon after the females appear. Gestation is from 26-28 days and litter sizes vary
from 4-11 but most often are 7-8. Young are altricial and leave the den after 30 days.
Adults produce only one litter per year and youngsters become sexually mature the spring
following their birth (Kurta, 1994; Wilson & Ruff, 1999; Nowak, 1991).
Habitat
Franklin’s ground squirrel can be found in areas of tall grass prairie. It prefers grass of
intermediate height, tall enough to hide the animal when on all four feet but low enough
to see over when standing upright on the hind legs. It lives along forested grassland
edges, fencerows bordering cropland, tall grasses along railroads and marshland edges.
They sometimes use abandoned burrow systems of northern pocket gophers during the
day as well as at night, this also influences above ground movements during the day
(Kurta, 1994; Lewis & Rongstad, 1992; Choromanski-Norris et al. 1989).
Food Habits
Diet consists of fruits, seeds and vegetable fibers from plants such as grass, thistle,
dandelion, clover, and black berry, along with cultivated grains and garden vegetables.
Up to one third of its diet consists of animal flesh, mainly insects. Caterpillars,
grasshoppers, crickets, and ants are the most common prey but they will occasionally
consume a frog, toad, nestling bird, bird egg or mouse. However, it has been found that
Franklin’s ground squirrel is a big predator of duck nests, including the eggs and young
waterfowl (Sabine, 1912; Kurta, 1994; Sowls, 1948).
Ecology and Behavior
Franklin ground squirrels are diurnal mammals that are fairly sedentary and rarely
venture more than 100m (330 ft) from their burrows. They stay underground quite a lot
and only spend approximately 10% of their life above ground (Sowls, 1948). It can
climb trees but mostly forages for food on the ground. (Nowak, 1991; Kurta, 1994).
Franklin ground squirrels are relatively inconspicuous and they immediately seek refuge
in their burrows when alarmed. Known predators are Red-Tailed Hawk, Red Fox,
Badger, Coyote, Skunk, Mink, Long-Tailed Weasels and possibly owls (Baker, 1983).
They are less social than other ground squirrel species but do live in loose aggregations.
They are known to make a variety of calls that are described as being clear and musical
but the meaning of these calls is not known. Sometimes their distinctive call causes them
to be known as whistle pigs (Sowls, 1948).
Remarks
Was named after the Arctic explorer, Sir John Franklin.
Original name was Arctomys franklinii, Sabine, 1822
Other names; Myotis thysanodes, Citellus franklinii.
Gray gophers, Franklin’s Prairie squirrel, Gray Prairie squirrel, or whistling squirrel.
Franklin’s ground squirrels can swim if they have to.
Sardines are used as bait to live trap a Franklin’s ground Squirrel.
References
Kurta, Allen.1994. Mammals of the Great Lakes Region, The University of Michigan
Press. Ann Arbor. p. 118-120.
Sowls, Lyle K. 1948. The Franklin ground squirrel, Citellus franklinii (Sabine), and its
relationship to nesting ducks. Journal of Mammalogy, p.113-137.
Wilson, D. E.; Sue Ruff, ed., 1999. The Smithsonian Book of North American Mammals.
Smithsonian Institution Press, Washington, D.C. p. 282-283.
Murie, Jan. O. 1973. Population characteristics and phenology of a Franklin ground
squirrel (Spermophilus franklinii) colony in central Alberta. American Midland
Naturalist, 90: 334-340.
Choromanski-Norris, Jane; Erik K. Fritzell; Alan B. Sargeant. 1989. Movements and
Habitat Use of Franklin’s Ground Squirrels In Duck-Nesting Habitat. Journal of Wildlife
Management, 53(2): 324-331.
Choromanski-Norris, Jane; Erik K. Fritzell; Alan B. Sargeant. 1986. Seasonal Activity
Cycle And Weight Changes of The Franklin’s Ground Squirrel. American Midland
Naturalist, 116(1): 101-107.
Nowak, R. M. 1991. Walker’s Mammals of the World, Johns Hopkins University Press,
Baltimore, MD.
Lewis, T. L.; O. J. Rongstad. 1992. The Distribution Of Franklin’s Ground Squirrel in
Wisconsin and Illinois. Wisconsin Academy of Sciences, Arts and Letters. Transactions,
80:57-62.
Iverson, S. L.; B.N. Turner. 1972. Natural History of a Manitoba Population of
Franklin’s Ground Squirrels. The Canada Field Naturalist. 86:145-149.
Erlien, D. A.; J.R. Tester. 1984. Population Ecology of Sciurids in Northwestern
Minnesota. The Canadian Field-Naturalist. 98:1-6.
Cory, Charles B. 1912. The Mammals of Illinois and Wisconsin. Field Museum of
Natural History. 153(XI): 144-149.
Eagle, T.C.; J. Chromanski-Norris; V.B. Kuechle. 1984. Implanting Radio Transmitters
in Mink and Franklin’s Ground Squirrels. Wildlife Society Bulletin. 12:180-184.
Available On-line: November 14, 2003.
Franklin’s Ground Squirrel: vanishing prairie hibernator. Chicago Wilderness Magazine.
2002.
http://chicagowildernessmag.org/issues/winter2002/franklins.html
Franklin’s Ground Squirrel. http://www.ku.edu/-mammals/sperm-frank.html
Reference written by Kristen Cragin, Biology 378 student. Edited by Christopher Yahnke.
Page last updated.