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Black-Tailed Prairie Dogs
Black-Tailed Prairie Dogs
Key Messages and Themes
Prairie dogs are fascinating animals for reasons that are obvious – they are busy, social,
charismatic rodents – and for reasons that are worth discovering. This is the first most important
message to convey to Zoo visitors: that there’s more to prairie dogs than meets the eye, and that
the more you get to know them, the more fascinating they become.
There are five recognized species of prairie dog and all are native to North America. The most
common species is the black-tailed prairie dog, which we have on exhibit at the Zoo. Black-tailed
prairie dogs are native to short- and mid-grass prairies of the American Midwest.
KEY MESSAGES:
1. Nature of Science: Science as a discipline and as it pertains to any particular topic is constantly
evolving. This is because knowledge is always being gained and the world (which provides all the
reference points) is constantly changing. Even if there were a moment in time when we could say
we knew absolutely everything there was to know at that moment in time about elephants, for
example, the need to continue scientific research on elephants would still exist because
something about how elephants live would change in that very instant. Conditions are never static
and knowledge is forever cumulative, so science by definition is always evolving.
Prairie dogs as a subject of scientific inquiry are a great case in point. Biologists still have a great
deal to learn about these animals. New methods and tools of observation and research are
allowing biologists to accumulate data that was never available to them before, and biologists are
asking and trying to answer questions that have never been studied in depth before, so what we
know about prairie dogs and how they live is still coming into focus. This is important to realize,
because as leading prairie dog biologists like John Hoogland will tell you, sound wildlife
management decisions must – and can only be – based on comprehensive understanding of a
species’ biology and natural history. Understanding the biology must come first.
2. Conservation is complex. Species reach a point of needing to be conserved for complex reasons,
and arriving at workable solutions to achieve conservation is equally complex. In order to attain
workable solutions and achieve sustainable conservation policy, you always have to factor in the
human – habitat – animal (or plant) triangle. This is true in absolutely every instance, including
with black-tailed prairie dogs.
3. Prairie Dogs are burrowing ground squirrels. They belong to the Squirrel family and are members
of the Ground and Tree Squirrel subfamily. However, prairie dogs are very different from pocket
gophers, moles, and other animals that live most of their lives underground. Prairie dogs are
Sarah Evans; edited/updated May 2013 by SBowen
6/5/2013
Compiled from research notes and interviews, exhibit signage, website content, and Zoogram article
1
The Maryland Zoo in Baltimore
Black-Tailed Prairie Dogs
mainly above-ground animals. They go below ground only to sleep, mate, and nurse newborn
young. They are diurnal animals (active during the day), and are above ground most days of the
year from dawn until dusk.
Life below ground:
Contrary to popular belief, black-tailed prairie dogs do not create extensive, interconnected
underground cities. Their burrows are extremely simple. They do not have underground
latrines. They do not cache food underground. You might see a black-tailed prairie dog with
a mouthful of grass going below ground, but it’s always dry grass like hay, so it’s probably
being used for nesting material.
Researchers have learned the following:
a. The simplest and most common black-tailed prairie dog burrow is U-shaped. It looks like
a fishing hook, with the lodge at the end of the hook.
b. A more complex version of a black-tailed p.d. burrow might have 2 entrances rather
than just 1, and might have 2 or 3 lodges leading off main tunnel rather than just a
single lodge, but that’s about as complex a burrow as you’re going to find.
c. Activity below ground is limited. Prairie dogs go underground to sleep, escape bad
weather and predators, mate, and nurse newborn young for about the first 6 weeks of
life. That’s it. Everything else occurs above ground.
d. In sum, what you will and won’t find in a black-tailed prairie dog burrow:
i. You will find a grass-lined chamber at the end of a tunnel.
ii. You might find more than one chamber (2-3) at the end of side tunnels off the
main tunnel, but you won’t find much more than this.
iii. You might find 2 entrances to the same burrow, maybe 3, but probably no
more.
iv. You won’t find underground latrines.
v. You won’t find underground food storage areas. Prairie dogs eat above ground.
During the winter months when food is scarce, black-tailed prairie dogs do not
technically hibernate but are dormant through the winter, meaning that they
sleep more and essentially fast, living off reserve body fat.
vi. You won’t find “nursery” chambers constructed or occupied separately from
“overnight” chambers. The way it works is that all burrows within a coterie are
communal up until the moment that a female mates, at which point she lays
claim to a single burrow in the coterie and won’t let anyone else enter it. She
temporarily turns this standard burrow into her “nursery” for the duration of
her pregnancy and the first six weeks of her offsprings’ lives.
Sarah Evans; edited/updated May 2013 by SBowen
6/5/2013
Compiled from research notes and interviews, exhibit signage, website content, and Zoogram article
2
The Maryland Zoo in Baltimore
Black-Tailed Prairie Dogs
Life above ground:
Above ground, you’ll see prairie dogs engaged in all sorts of activities, including digging,
dusting, tidying, playing, squabbling, napping, foraging, eating, grooming, greeting relatives,
chasing trespassers, keeping watch, sounding alarms, scurrying for cover, and slipping back
into the sunshine once the coast is clear. Two activities particularly worthy of discussion are
standing watch, tidying, and foraging.
a. At any given time, one or more prairie dogs are literally standing watch – up on
their back legs, atop the mounds that mark the entrance to their burrows –
scanning the earth and sky for predators. When it senses a threat, it lets out a
distinctive bark (for which the animal gets its name) that all others know as the
“anti-predator call.” This bark will unleash a chorus of fellow barks and all prairie
dogs will scurry below ground to take temporary refuge. Rather than going many
feet underground to their actual burrows, prairie dogs usually sit just inside the
burrow entrance in a widened turn-around spot. They’ll wait for threat to pass, and
emerge when coast is clear. As they emerge, each prairie dog stands tall atop its
mound and jumps while emitting the tell-tale “jump-yip call” that basically says to
all others “I’m back! This is my territory!”
b. Prairie dogs spend much of their time tidying and firming up the mounds that mark
the entrances to their burrows. The reason for this is simple: the mounds provide
the only elevated lookout points available on the very flat and open prairie
landscape. They are crucially important to prairie dog security. You’ll see prairie
dogs working especially hard on their mounds after rainstorms when erosion has
occurred.
c. Prairie dogs usually forage for food close to their burrows. They eat a combination
of grasses, weeds, and forbs and are selective in what they eat, which means that
they prefer some species of plant and avoid others. They influence the surrounding
plant community in that their presence improves the quality of certain plants while
limiting the growth of others. In addition to foraging for food, prairie dogs clip tall
vegetation all around the colony in order to maintain a clear line of sight.
4. Prairie dogs live in colonies. Prairie dogs are very well known for the large colonies they create,
also referred to as “prairie dog towns.” These are permanent settlements where residents live
year-round. Each colony is subdivided into individual family territories known as coteries. Family
members will defend their coteries from interloping neighbors. Males chase other males away
Sarah Evans; edited/updated May 2013 by SBowen
6/5/2013
Compiled from research notes and interviews, exhibit signage, website content, and Zoogram article
3
The Maryland Zoo in Baltimore
Black-Tailed Prairie Dogs
and females chase off females.
a. Advantages and Disadvantages of Colonial Life:
Disadvantages:
i. Competition for resources: Prairie dogs must compete with each other for limited
food, nesting materials, and mates.
ii. Greater susceptibility to disease and parasites: Because they congregate in such
large and dense communities, prairie dogs are vulnerable to the rampant spread of
parasites and consequential epidemic outbreaks of disease. Many prairie dog
communities have recently been ravaged by outbreaks of bubonic plague, for
example, and this disease remains a serious threat to prairie dog survival.
Advantage: increased defense against predators
For prairie dogs, the big advantage of colonial life – thousands and maybe even millions of
eyes and ears watching and listening for predators – greatly outweighs all disadvantages.
The list of predators interested in eating prairie dogs is very long, and includes American
badgers, bobcats, long-tailed weasels, swift foxes, black-footed ferrets, coyotes, ferruginous
hawks, Cooper’s hawks, red-tailed hawks, golden eagles, prairie falcons, and rattlesnakes.
Social Life of Prairie Dogs:
Within a colony, prairie dogs live in contiguous, territorial family groups, or coteries. More than
20 prairie dogs may live in a single coterie, but most contain a single breeding adult male, 3 or 4
females, and several offspring. A distinct family hierarchy is established by fighting and scuffling
for dominance. Family members “kiss” and groom each other, graze together, play and chase,
help dig each other’s burrows, and chase trespassers away.
Mothers and daughters usually spend their entire lives within the natal coterie territory. As
males reach sexual maturity, they are chased off by the dominant male and will establish
burrows of their own on the edge of the colony where they will try to attract females and start
their own new coteries.
A typical coterie is about ½ acre in size and may have about 70 burrow entrances. Each coterie
must be large enough to provide adequate food for all family members.
For about eight months of the year, any member of a coterie can use any burrow, and members
often share burrows overnight. However, when breeding season starts, females will lay claim to
particular burrows and guard them as their nurseries. According to researcher John Hoogland, a
female black-tailed prairie dog that mates on Tuesday will turn into a nasty female on
Wednesday, choosing and then aggressively defending her nursery burrow. She will occupy and
defend only that burrow, and alone, until she gives birth and has nursed her young below
Sarah Evans; edited/updated May 2013 by SBowen
6/5/2013
Compiled from research notes and interviews, exhibit signage, website content, and Zoogram article
4
The Maryland Zoo in Baltimore
Black-Tailed Prairie Dogs
ground for 5-6 weeks.
SIDESTORY: PRAIRIE DOG INFANTICIDE (This is not a topic for all audiences!)
An interesting and somewhat dark side story to colonial life and the rearing of offspring
among black-tailed prairie dogs is that of infanticide. Infanticide – the killing of newborns –
occurs in hundreds of species across all taxonomic groups but is especially prevalent among
black-tailed prairie dogs (and this is particular to this species of prairie dog, not all species of
prairie dogs). Research suggests that infanticide accounts for the partial or total loss of
nearly 40% of all litters born within prairie dog colonies. The killers are usually closely
related female kin. In other words, if you’re a newborn prairie dog, you’re quite likely to be
killed by a marauding older sister, aunt, or grandmother. These marauding females are
usually lactating themselves and will actually leave their own nurseries to invade other
nurseries and kill newborns during the earliest weeks of life. The reasons for black-tailed
prairie dog infanticide are not fully understood and require further research.
5. Prairie Dogs are a keystone species. Keystone species have tremendous and unique impact on
many other species of plants and animals in their native ecosystem, generally out of proportion to
their actual numbers. Black-tailed prairie dogs are a keystone species in their grassland
ecosystem. They influence their ecosystem directly and indirectly via three main pathways:
grazing, burrowing, and as prey. With their constant foraging and clipping of vegetation in and
around their colonies, prairie dogs influence plant life within their colonies. Their behavior
encourages the growth of certain species and limits that of others, but it should be made clear
that prairie dogs do not eat rampantly and indiscriminately. They are selective feeders. All
vegetation in the vicinity of a prairie dog colony is kept low to the ground, though, because prairie
dogs both eat and clip vegetation to maintain a clear line of sight.
As prey, black-tailed prairie dogs impact many species of animal. Their colonies attract many
predators, and they are an important food source to American badgers, black-footed ferrets,
coyotes, ferruginous hawks, golden eagles, prairie falcons, among others.
Black-tailed prairie dogs also influence their ecosystem and impact other species in many other
ways. Several species make use of prairie dog burrows, including burrowing owls, prairie
rattlesnakes, and tiger salamanders. The constant digging that prairie dogs do affects the cycling
of water and nutrients through soil, which impacts plant and animal species, including such
organisms as protozoans, arachnids, mites, and insects. Prairie dogs also support many species of
parasite. If black-tailed prairie dogs were to disappear from the short-grass prairies of the
American Midwest, the ecosystem that they once inhabited would be drastically changed.
6. Prairie dogs are a native North American species that was in steep decline. (Note: The exhibit
signage is out of date; status is no longer “Under Review”)
Two hundred years ago, American prairies teemed with black-tailed prairie dogs. The western
explorer Meriwether Lewis described their number as “infinite,” with a more realistic population
Sarah Evans; edited/updated May 2013 by SBowen
6/5/2013
Compiled from research notes and interviews, exhibit signage, website content, and Zoogram article
5
The Maryland Zoo in Baltimore
Black-Tailed Prairie Dogs
estimate still exceeding five billion. Their numbers plummeted, however, over the past two
centuries as many ranchers killed them as pest species and as their habitat was plowed under for
agriculture and land development. Yet in December 2009, following a review of the status of the
species, the U.S. Fish and Wildlife Service announced that black-tailed prairie dogs did not warrant
protection as a threatened or endangered species under the Endangered Species Act. . This
decision was not announced without controversy. The long-term survival of black-tailed prairie
dogs may continue to be jeopardized by vanishing habitat, disease, recreational shooting, and
concerted eradication efforts such as poisoning and flooding of colonies. They are also currently
threatened by outbreaks of bubonic plague, to which they are fatally susceptible.
The black-tailed prairie dog is identified as Least Concern (IUCN) and the species is currently not
listed by USFWS.
For more information from the USFWS about prairie dogs and their status, you can visit their
website: http://www.fws.gov/mountain-prairie/species/mammals/btprairiedog/
Natural History Information in Brief
Black-tailed Prairie Dogs (Cynomys ludovicianus)
Status: not listed by FWS; least concern (IUCN)
Habitat: short- and mid-grass prairies of North America
Diet: HERBIVORE: grasses and forbs, occasional insects
Active: Diurnal
Life Span: 5-8 years
Reproduction/Offspring: 3-4/litter/year
Length: 14-17 in (350-425 mm)
Weight: 1-3 pounds
Social Structure: colonial
Adaptations
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Claws and whiskers, useful for navigating below ground
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Wide-set eyes, useful for scanning vast landscape for predators
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Light-beige fur, provides excellent camouflage against backdrop of dirt
Sarah Evans; edited/updated May 2013 by SBowen
6/5/2013
Compiled from research notes and interviews, exhibit signage, website content, and Zoogram article
6
The Maryland Zoo in Baltimore
Black-Tailed Prairie Dogs
References:
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Maryland Zoo website: http://www.marylandzoo.org/animals-conservation/mammals/blacktailed-prairie-dog/
“Prairie dogs as you’ve never seen them before,” summer 2009 Zoogram
Hoogland, John L. The Black-Tailed Prairie Dog: Social Life of a Burrowing Mammal. Chicago:
University of Chicago Press, 1995.
Hoogland, John L., ed. Conservation of the Black-Tailed Prairie Dog: Saving North America’s
Western Grasslands. Washington, D.C.: Island Press, 2006.
U.S. Fish and Wildlife: http://www.fws.gov/mountain-prairie/species/mammals/btprairiedog/
Sarah Evans; edited/updated May 2013 by SBowen
6/5/2013
Compiled from research notes and interviews, exhibit signage, website content, and Zoogram article
7