Region 6 Mountain Prairie Region
Black-footed ferret / USFWS
Black-footed ferret in precondition-ing
pen / USFWS
Black-footed ferret kits / USFWS
U.S. Fish & Wildlife Service
Mustela nigripes
Black-footed Ferret
Species Description
The black-footed ferret (Mustela
nigripes) is a medium-sized
mustelid (a member of the weasel
family), typically weighing 1.4 to 2.5
pounds and measuring 19 to 24
inches in total length, including a 5
to 6 inch tail. It is a slender, wiry
animal with black feet, a black face
mask, and a black-tipped tail. Its
short, sleek fur is a yellow-buff
color, lighter on the belly and nearly
white on the forehead, muzzle, and
throat. Black-footed ferrets have
short legs with large front paws,
and claws developed for digging.
The ferret’s large ears and eyes
suggest it has acute hearing and
sight, but smell is likely its most
important sense for hunting prey
underground in the dark. Its large
skull and strong jaw and teeth are
adapted for eating meat.
Specialization
The black-footed ferret is a highly
specialized predator that depends
upon prairie dogs for survival.
Prairie dogs (Cynomys spp.) make
up more than 90% of the black-footed
ferret’s diet, and prairie dog
burrows provide ferrets with
suitable dens to raise their young,
as well as a means to escape from
predators and harsh weather. In the
evolutionary past, this dependence
was a very good survival strategy
because prairie dogs were plentiful.
However, in the modern era, as
human activities and disease have
decimated prairie dog populations,
this unique survival strategy has
proven detrimental to ferret
survival.
Habitat & Range
The black-footed ferret depends
exclusively on prairie dog burrows
for shelter. Historically, ferret
habitat largely coincided with the
habitats of the black-tailed prairie
dog (C. ludovicianus), Gunnison’s
prairie dog (C. gunnisoni), and the
white-tailed prairie dog (C.
leucurus). The black-footed ferret is
the only ferret species native to the
Americas. Its historic range
spanned much of western North
America’s intermountain and prairie
grasslands, extending from Canada
to Mexico. The species now exists in
the wild at 16 reintroduction sites
across 8 states, Canada, and Mexico
(3 of the 19 original reintroduction
sites no longer support ferret
populations due to sylvatic plague).
Reproduction
Mating Season: March -April.
Gestation: 41 to 43 days. Kits are
born May through June.
Litter size: Typically 3 to 4 kits. Kits
are born blind and helpless, and stay
below ground until they are about 2
months old. At this age, mother
ferrets move their litters to various
burrows within their home range,
and begin to take them on hunting
forays. At 90 days of age, kits reach
90% of their adult size, and are able
to kill prairie dogs.
Threats
Despite significant recovery
successes, the black-footed ferret
remains one of the most endangered
animals in the world. The primary
reasons the species remains at risk
are the same that nearly caused the
animal’s extinction: loss of habitat
and prey. Conversion of native
grasslands to agricultural land,
widespread prairie dog eradication
programs, and fatal, non-native
diseases have reduced ferret habitat
to less than two percent of its
original range. The remaining
habitat is now fragmented,
Region 6 Mountain Prairie Region
with prairie dog towns
separated by expanses
of agricultural land
and other human
developments.
Legal Status under the Endangered
Species Act
Since March 11, 1967, the black-footed
ferret has been listed as
endangered across its entire range,
with the exception of several
reintroduced populations
designated as experimental. In
November 2008, the U.S. Fish and
Wildlife Service (Service) completed
a 5-year review of black-footed
ferret recovery efforts. This review
found that the species remains one
of the most endangered mammals in
the United States, and continues to
warrant endangered status.
Population Numbers and Recovery
Efforts
Black-footed ferrets once numbered
in the tens of thousands, but a
combination of human-induced
threats brought them to the brink of
extinction in the 20th century. In
fact, the species was twice believed
by scientists to be extinct. In 1986,
only eighteen individuals were
known to exist in the entire world.
Scientists captured these ferrets,
which provided the foundation for a
successful breeding and
reintroduction program. As of 2011,
this U.S. Fish and Wildlife Service-led
program has since produced
more than 7,000 kits in captivity,
more than 2,600 of which have been
reintroduced into their natural
habitat. It is estimated that as a
result of these efforts there are
currently more than 1,000 black-footed
ferrets in the wild, and
another 280 living in breeding
facilities. These recovery efforts are
managed primarily by the National
Black-Footed Ferret Conservation
Center near Carr, CO (http://www.
blackfootedferret.org/).
Despite the radically-altered
environment facing reintroduced
Dean Biggins / USFWS
U.S. Fish and Wildlife Service
Region 6, NWRS
U.S. Fish and Wildlife Service
PO Box 25486
Denver Federal Center
Denver, Colorado 80225
308 / 382 6468
For State relay service
TTY / Voice: 711
U.S. Fish & Wildlife Service
http://www.fws.gov
December 2010
ferrets today, scientists believe that
the recovery of the species is within
reach. All of the components
necessary to achieve recovery have
been identified, and have proven
operationally successful in the field.
That said, there is still much work
to be done, and many potentially
complicating variables still exist.
However, if recovery efforts
continue at the current pace and do
not experience significant setbacks,
in time the Service and its partners
expect to recover the black-footed
ferret.
More Information
To learn more about the black-footed
ferret and conservation
efforts on behalf of the species,
please visit the following sites:
The Black-footed Ferret Recovery
Program: http://www.
blackfootedferret.org/
The U.S. Fish and Wildlife Service’s
ECOS page: http://ecos.fws.gov/
speciesProfile/profile/speciesProfile.
ode=A004
Wayne Lewis / USFWS
Lockhart / USFWS
