Types of Wolves
Biology & Behavior
Wolves & Humans
updated June 24, 2013
Most U.S. wolves outside of Alaska may be removed from the protection of the
Endangered Species Act. Here are 10 frequently asked questions about the proposal,
and information on how you can comment.
- What is being proposed? The U.S. Fish and Wildlife Service (FWS)
wants to remove the gray wolf (Canis lupus) from the list of endangered
species in the contiguous United States.
- What would the proposed change NOT do? It would not remove
protection from the Mexican wolf (Canis lupus baileyi), which would be
listed as an endangered subspecies. About 75 Mexican wolves have been
reestablished in central Arizona and New Mexico. Two live in Mexico, and
more will be released there. The proposal also would not affect the endangered
status of red wolves (Canis rufus) in the Southeast, and recovery efforts
for them will continue.
- Where would wolves NOT be affected? Wolves have already been
delisted and are under state management in Minnesota, Michigan and Wisconsin
(Western Great Lakes population) and, Idaho, Wyoming and Montana, and
eastern Oregon and Washington (Northern Rocky Mountain population).
- In what states would wolves no longer be listed as an endangered species?
Alabama, Arkansas, California, Colorado, Connecticut, Delaware, Florida,
Georgia, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts,
Mississippi, Missouri, North Carolina, Nebraska, New Hampshire, New Jersey,
Nevada, New York, Oklahoma, Pennsylvania, Rhode Island, South Carolina,
Tennessee, Virginia, Vermont, and West Virginia; those portions of Arizona,
New Mexico, and Texas not included in the experimental population, and
portions of Iowa, Indiana, Illinois, North Dakota, Ohio, Oregon, South
Dakota, Utah, and Washington.
- In those 42 states, are wolves present now? Gray wolf packs are
known to be in Washington state and Oregon. Individual dispersing wolves
have been documented in California, Utah, Colorado, North Dakota, South
Dakota, Missouri, Indiana, Illinois, Maine and Nebraska and New York.
- Wasn't the Endangered Species Act required to restore wolves to their
entire historic range? The FWS says, "The Act does not require us to
restore the gray wolf (or any other species) to all of its historical range
or even to a majority of the currently suitable habitat. Instead, the Act
requires that we recover listed species such that they no longer meet the
definitions of "threatened species" or "endangered species, i.e., are no
longer in danger of extinction now or in the foreseeable future. For some
species, recovery may require expansion of their current distribution, but
the amount of expansion is driven by a species' biological needs affecting
viability and sustainability, and not by an arbitrary percent of a species'
historical range or currently suitable habitat. Many other species may be
recovered in portions of their historical range or currently suitable habitat
by removing or addressing the threats to their continued existence. And some
species may be recovered by a combination of range expansion and threats
reduction. There is no set formula for how recovery must be achieved."
- What are some commonly stated pro/con comments about the proposal?
PRO: Wolves are recovered, according to biological standards, with a
population of about 6,100 in many areas of the U.S. where there is enough
wild prey, good habitat and minimum road- and human-density.
CON: One school of thought holds the following view: The Service's portrayal
of recovery disregards the full definition for threatened (any species
likely to become endangered within the foreseeable future throughout all
or a significant portion of its range) and endangered (any species
likely to become extinct within the foreseeable future throughout all or
a significant portion of its range) species. The FWS perspective does not
meet the 1973 regulations (amended from legal antecedents in 1966 and 1969).
The Service cannot ignore the geographic component of recovery. Moreover,
the FWS cannot implement the Act in a manner consistent with Congressional
intent and previous agency action by equating "its range" with "its
current range". "Its range" has to equate with "its historical range"
for the ESA to have the broad sweeping impact intended by Congress and
for previous agency actions to have relevance to future agency actions.
Otherwise there would be no recovery program for the black-footed ferret,
California condor, red wolf, and Mexican wolf, to name just a few species
that existed only in captivity and therefore had no current range prior
to ESA-authorized reintroduction programs.
PRO: Delisting will help states without wolves, in that if wolves recolonize
those states, they can be managed like other species without special
CON: The nationwide delisting would make it less likely that wolves will
repopulate, on their own, parts of Colorado, Utah, Nevada, California and
New England. In particular, suitable high-quality habitat is abundant in
the Southern Rockies Ecoregion.
PRO: Delisting wolves would prove that the ESA works, making Congress
less likely to amend or repeal it.
CON: One canÕt say that the ESA works if it embraces a simplistic
perspective of success and does not meet its own stated criterion for
recovery of a species.
PRO: As management for wolves passes to the states, wolves will still be
protected so that their populations never dip below the numbers set in
the ESA's recovery plan.
CON: Where states have assumed management of wolves they have instituted
or plan controversial recreational hunting and trapping seasons, that,
for animal protectionists, seem to subvert the whole purpose of past wolf
PRO: Scarce federal funds that would have been used for continued wolf
recovery can now be allocated for many lesser-known endangered species
on a lengthy waiting list.
CON: Not many federal funds have been spent on wolf recovery in states
other than those where wolves have recovered.
- Where can I read the entire proposed rule change? Visit the
Regulations.gov Web site.
- How can I comment on the proposed delisting? The 90-day public
comment period extends through October 28, 2013. The easiest way to submit
a comment is to go to the
and click on the "What's Trending" section on the gray wolf proposal. Or
you can mail a comment to Public Comments Processing, Attn: FWS-HQ-ES-2013-0073;
Division of Policy and Directives Management; U.S. Fish and Wildlife Service;
4401 N. Fairfax Drive, MS 2042-PDM; Arlington, Virginia 22203.
- When can I find out about public hearings? Times, dates and
locations for public hearings on the proposal during the 90-public comment
period will be announced 15 days before the events.
updated July, 2011
Researchers are discovering more about wolves every year. Direct observation of
these complex and intelligent animals in places like the high arctic and Yellowstone,
advances in genetics, and sophisticated tracking devices have unlocked many secrets.
But much about the wolf remains a mystery, and the adage "Never say "Never," and
never say "Always" when the subject is wolves is still true. Full articles and
scientific papers have been written about each of the following questions. We
recommend that you search the Web site for more comprehensive information including
the "Books and Videos About Wolves" section under Basic Wolf Information. At the
end of the FAQ list are three recommendations for obtaining accurate, science-based
facts and information.
How many species of wolves are there in the world? There are two universally
recognized species of wolves in the world: the gray wolf (Canis lupus) and
the red wolf (Canis rufus). Two other members of the canine family are considered
to be wolves by some researchers and other species by other researchers. The use of
molecular genetic research on wolves is suggesting that there may be two more species
of wolf in the world. Some scientists question whether the Ethiopian or Abyssinian
wolf (Canis simensis) is a true wolf or a jackal. Other researchers have
presented strong evidence that the eastern timber wolf (Canis lupus lycaon),
may be a distinct species, the eastern wolf (Canis lycaon). Due to the complex
nature of studying wolves using molecular genetics to distinguish species, the process
takes a great amount of time to reach solid conclusions.
What are the subspecies (races) of the gray wolf? The gray wolf, Canis
lupus, lives in the northern latitudes around the world. There are five subspecies,
or races, of the gray wolf in North America and seven to 12 in Eurasia. The currently
recognized subspecies in North America are:
- Canis lupus baileyi - the Mexican wolf or lobo.
- Canis lupus nubilus - the Great Plains or buffalo wolf.
- Canis lupus occidentalis - the , Rocky Mountain or MacKenzie Valley wolf.
- Canis lupus lycaon - the eastern timber wolf. Some scientists maintain this wolf is a separate species, Canis lycaon.
- Canis lupus arctos- the arctic wolf.
Subspecies are often difficult to distinguish from one another. This is because
wolves are so mobile and travel such great distances. They interbreed where their
ranges overlap so that their populations tend to blend together rather than form
distinctive boundaries. The different traits we see in subspecies are likely the
result of geographic range, available habitat, and prey base. But one wolf is, in
reality, like any other wolf in terms of natural history and behavior. There are
far more commonalities among wolves than differences. All species and subspecies of
wolves are social animals that live and hunt in families called packs, although adult
wolves can and do survive alone. Most wolves hold territories, and all communicate
through body language, vocalization and scent marking.
Is the red wolf a true wolf or a wolf/coyote hybrid? No single hypothesis
for the origin of the red wolf is universally accepted by scientists. DNA analysis
and morphological evidence support recognition of the red wolf as a distinct species.
(See Wolves: Behavior, Ecology, and Conservation - Chapter 9).
What are the main differences between red wolves and gray wolves? Red wolves
are larger than coyotes and smaller than gray wolves. They are buff-colored or brown
with some black along their backs. The backs of their ears, head and legs are often
tinged with a reddish color. Their legs are long, and they have tall, offset ears.
The red wolf diet consists mainly of white-tailed deer and small mammals such as marsh
rabbits, raccoons and nutria.
What is the legal status of the red wolf?The red wolf has federally
endangered status throughout its 29-state historic range. Non-essential experimental
status (see Glossary)
applies only to the 5-county red wolf recovery area comprising the Albemarle Peninsula
in northeastern North Carolina.
What is a wolf pack?A wolf pack is a cohesive family unit consisting of
the adult parents and their offspring of the current year and perhaps the previous
year and sometimes two years or more. Wolf parents used to be referred to as the
alpha male and alpha female or the alpha pair. These terms have been replaced by
"breeding male," "breeding female," and "breeding pair" Š or simply "parents." The
adult parents are usually unrelated, and other unrelated wolves may sometimes join
How many wolves are in a pack? Pack size is highly variable and fluid
because of the birth of pups, dispersal, and mortality. Prey availability and size
are also factors. Where prey animals are smaller, packs are often small. Where prey
is large, the packs may be larger. For example, in Alaska and northwestern Canada
some packs reportedly have over 20 members. One pack (Druid Peak pack) in Yellowstone
National Park once swelled to over 30 members, but this is highly unusual and not
necessarily an advantage. More pack members means more food must be obtained. Wolf
packs are generally largest in late autumn when the nearly-grown pups are strong
enough to hunt with the adults. Over the winter months, some wolves may disperse to
find mates and territories of their own. Others die, and by spring, before the arrival
of a new crop of pups, the pack size has often diminished.
Red wolf packs are generally smaller than gray wolf packs and usually have 2 to 8
members, but a pack of 12 has been observed in the wild.
What is the size of a wolf pack territory? In most regions where wolves
live, each wolf pack has its own territory, an area in which it lives, hunts and
raises its offspring and which it actively defends against other canids (dog-like
animals) including other wolves. Exceptions are nomadic wolves whose prey is migratory
such as the tundra wolves that follow the caribou herds on their annual treks over
huge distances. Territory size is highly variable and depends on a number of factors
such as prey abundance, the nature of the terrain, climate and the presence of other
predators including other wolf packs. Gray wolf territories in the lower 48 states
may be less than 100 square miles while territories in Alaska and Canada can range
from about 300 to 1,000 square miles or more.
Red wolf territories in northeastern North Carolina vary in size, but most are
estimated to range between 38 to 87 square miles.
When do wolves breed? Wolves breed once a year in late winter or early spring
depending on where they live. For example, gray wolves in the Western Great Lakes
region breed in February to March, while gray wolves in the arctic may breed a few
weeks later - in March to April.
Red wolves usually breed in late January or early February.
What is the gestation (pregnancy) period of a wolf? The gestation period
(length of pregnancy) of gray and red wolves is usually around 63 days.
How many pups are born in a pack each year? A mature female wolf comes into
estrus once a year. Thus, a breeding pair produces one litter of pups each spring,
but in areas of high prey abundance more than one female in a pack may give birth.
An average litter size for gray and red wolves is 4 to 6, but sometimes fewer pups
are born and sometimes more. Several or all may die if food is not readily available
for the fast-growing youngsters. Additionally, other predators and diseases such as
distemper and canine parvovirus may kill young pups.
How much do wolf pups weigh? Gray and red wolf pups weigh about a pound at
birth. The newborns are blind and deaf and depend upon their mother for warmth. In
about two weeks, their eyes open, and in three weeks, they emerge from the den and
begin to explore their world. Growth is rapid, and by the time the pups are 6 months
old, they are almost as big as the adults.
How much do adult wolves weigh? Wolves vary greatly in size depending on
where they live. The smallest wolves live in the southern parts of the Middle East
where the Arabian wolf may weigh no more than 30 pounds. Adult female gray wolves in
northern Minnesota weigh between 50 and 85 pounds, and adult males between 70 and
110 pounds. Gray wolves are larger in the northwestern United States, Canada, and
Alaska and in Russia where adult males weigh 85 to 115 pounds and occasionally reach
130 pounds. Males generally weigh about 20 percent more than females. Wolves attain
their adult height, length and weight in the first one to two years. Most look like
adults by late autumn of their first year.
Red wolves are intermediate in size and appearance between a gray wolf and a coyote.
Adult female red wolves weigh 40 to 75 pounds, while males weigh from 50 to 85 pounds.
How long and tall are wolves? As with weight, a wolf's length and height
are variable in different areas of the world. The figures that follow are commonly
used to describe the larger subspecies of wolves in North America, Europe and central
Asia. They are not accurate for several of the smaller subspecies in the southern
latitudes of the Middle East, for example. The average length (tip of nose to tip of
tail) of an adult female gray wolf is 4.5 to 6 feet; adult males average 5 to 6.5 feet.
The average height (at the shoulder) of a gray wolf is 26 to 32 inches.
The average length (tip of nose to tip of tail) of an adult red wolf is 4.5 to 5.5
feet. The average height (at the shoulder) of an adult red wolf is about 26 inches.
How big is a wolf's track? The size of a wolf's track is dependent on the
age and size of the wolf, as well as the substrate the track was made in. A good
size estimate for a gray wolf's track size is 4 1/2 inches long by 3 1/2 inches wide.
In comparison, a coyote's track will be closer to 2 1/2 inches long by 1 1/2 inches
wide. Only a few breeds of dogs leave tracks longer than 4 inches (Great Danes, St.
Bernards, and some bloodhounds). Red wolves have smaller feet than gray wolves.
All wolves have feet superbly adapted to long-distance travel over different types of
terrain and through (and over!) snow. The wolf's blocky feet and long, flexible toes
conform to uneven terrain, thus allowing the animal to maintain speed when necessary as
well as a tireless, ground-eating trot when traveling.
How many teeth does an adult wolf have? Adult gray and red wolves have 42
highly specialized teeth, while adult humans have 32. The canine teeth, or fangs, can
be 2 1/2 inches long and are used for puncturing and gripping. The incisors are for
nipping small pieces of meat; the carnaissial teeth are like scissors and knives.
Wolves use them to sheer flesh away from bones. Molars are for
grinding and crushing.
How strong are wolves' jaws?The massive molars and powerful jaws of a wolf
are used to crush the bones of its prey. The biting capacity of a wolf is 1,000 to
1,500 pounds of pressure per square inch. The strength of a wolf's jaws makes it
possible to bite through a moose femur in six to eight bites. In comparison, a German
shepherd has a biting pressure of 750 pounds per square inch. A human has a much lower
biting pressure of 300 pounds per square inch.
What do wolves eat? Wolves are carnivores, or meat eaters. Gray wolves prey
primarily on ungulates - large, hoofed mammals such as white-tailed deer, mule deer,
moose, elk, caribou, bison, Dall sheep, musk oxen, and mountain goats. Medium-sized
mammals, such as beaver and snowshoe hares, can be an important secondary food source.
Occasionally wolves will prey on birds or small mammals such as mice and voles, but
these are supplementary to their requirements for large amounts of meat. Wolves have
been observed catching fish in places like Alaska and western Canada. They will also
kill and eat domestic livestock such as cattle and sheep, and they will consume carrion
if no fresh meat is available. Some wolves eat small amounts of fruit, although this
is not a significant part of their diet. If prey is abundant, wolves may not consume
an entire carcass, or they may leave entire carcasses without eating. This is called
"surplus killing" and seems inconsistent with the wolves' habit of killing because
they are hungry. Surplus killing seems to occur when prey are vulnerable and easy to
catch - in winter, for instance, when there is deep snow. Since wolves are programmed
to kill when possible, they may simply be taking advantage of unusual situations when
wild prey are relatively easy to catch They may return later to feed on an unconsumed
carcass, or they may leave it to a host of scavengers. Additionally, they may cache
food and dig it up at a later time.
Red wolves primarily prey on white-tailed deer, raccoons, rabbits, nutria and other rodents.
How much do wolves eat? Getting enough to eat is a full-time job for a wolf.
When wolves catch and kill a large
mammal, they will gorge and then rest while the food is being rapidly digested. They will
generally consume all but the hide, some of the large bones and skull and the rumen (stomach
contents of ungulates) of their prey. Gray wolves can survive on about 2 1/2 pounds of
food per wolf per day, but they require about 7 pounds per wolf per day to reproduce
successfully. The most a large gray wolf can eat at one time is about 22.5 pounds. Adult
wolves can survive for days and even weeks without food if they have to. Growing pups,
however, require regular nourishment in order to be strong enough to travel and hunt with
the adults by the autumn of their first year. Wolves often rely on food they have cached
after a successful hunt in order to see them through lean times.
Red wolves may eat 2 to 5 pounds of food per day when prey is abundant. Because they
are smaller than gray wolves, they can consume less at one time than their larger cousins.
But like all wolves, eating for red wolves is a matter of "feast" followed by "famine."
How many prey animals do wolves kill per year? Wolves depend on a variety of large ungulates (hoofed animals) for food. Although
studies have been conducted in some areas to determine the actual number of prey killed
each year, the results are estimates. For example, an estimate for deer ranges from 15
to 19 adult-sized deer per wolf per year. Given the 2008 estimate of 2922 wolves in Minnesota,
for instance, that would equal 43,800 to 58,500 deer killed by wolves. In comparison,
hunters killed approximately 260,000 deer in the 2007 deer harvest. Additionally, several
thousand deer are killed during collisions with vehicles each year.
How long do wolves live? It is misleading to say that wolves in the wild live an average of a certain number
of years. There are so many variables. Some wolves die soon after they are born, and
others are killed or die in early or middle adulthood. Members of the dog family like
wolves and domestic dogs can live to be 15 or 16 years old - sometimes even older. Dogs
and wolves in captivity have a better shot at making it to a ripe old age because they
usually receive routine veterinary care and regular meals. However, wild wolves have a
tough life filled with pitfalls (see question #19). Many pups don't make it through the
first winter of their lives. Those that survive the first two years have a pretty good
chance of living another two to four years if they can avoid fatal injury and if they can
get enough to eat. Some wild wolves do live to be 9 or 10, and there are verified records
of a few living into their early teens.
What do wolves die from? The natural causes of wolf mortality are primarily starvation, which kills mostly
pups, and death from other wolves because of territory fights. Diseases such as mange,
canine parvovirus and distemper can be killers both in small and recovering populations
and in some established populations as well. Evidence suggests, however, that large wolf
populations build up a resistance to canine parvovirus. Lyme disease also infects wolves,
and heartworm can reduce a wolf's endurance by restricting blood flow to the lungs. Injuries
caused by prey result in some deaths. The large mammals that wolves hunt and kill can
inflict mortal injuries with antlers and hooves. Human-caused mortality including legal
(hunting and trapping in some locales) and illegal (poaching) activities can be high in
some populations. Wolves are sometimes hit by cars in areas where road density is high.
Pup mortality rates are highly variable, but approximately 40 to 60% of wolf pups die
How fast can wolves run?Wolves will travel for long distances by trotting at about five miles per hour. They
can run at speeds of 36 to 38 miles per hour for short bursts while chasing prey. Although
bursts of maximum speed are relatively short, wolves can maintain pursuit of running prey
animals for long distances and over rough terrain.
How far can wolves travel?Wolves are hunters, and they travel far and wide to locate prey. They may travel 50
miles or more each day in search of food, and they are superbly designed for a life on
the move. Because their elbows turn inward, their lean bodies are precisely balanced over
their large feet. With their long legs and ground-eating stride, they can travel tirelessly
for hours on end with no energy wasted. Dispersing wolves, those leaving packs in search
of their own mates, have been known to travel hundreds of miles away from their home
territory. Satellite and Global Positioning Satellite (GPS) collars allow researchers to
document the truly remarkable travels of wolves.
Why do wolves howl?The howl of the wolf is one of nature's most evocative and powerful sounds. The
haunting chorus of wolves howling is beautiful - or frightening depending on one's point
of view. Wolves howl to communicate with one another. They locate members of their own
pack by howling, and they often engage in a group howl before setting off to hunt. The howl
is a clear warning to neighboring wolves to stay away.
Are wolves dangerous to people?In a word, the general answer is no. Wolves typically avoid people. BUT! There are
several well-documented accounts of wild wolves attacking people in North America, and
although there were no witnesses, a 2007 inquest determined that a young man killed in
northern Saskatchewan in 2005 died as a result of a wolf attack. Accounts of wolves killing
people persist in India and in Russia and parts of central Asia. It is a fact that when
wild animals become habituated to people, they may lose their fear of humans, especially
if they are fed or if they associate humans with providing food. Like any large predator,
wolves are perfectly capable of killing people. No one should ever encourage a wolf or
any other wild animal to approach, and hikers and campers should take all necessary
precautions to prevent mishaps involving wildlife.
Will wolves disappear again from the lower 48 states if they are not federally
protected by the Endangered Species Act?It is unlikely. The general public is invested
in the return and recovery of the great predators on the landscape. Wolves reproduce
rapidly, and every spring brings a new pup crop to add to the growing numbers in the
areas where wolves have made a comeback. Wolves were eradicated in the 19th and early
20th Centuries by the federal government's systematic poisoning campaign. It is probably
safe to predict that this practice will never be repeated.
Wolves: Behavior, Ecology, and Conservation. L. David Mech and Luigi Boitani.
The University of Chicago Press, 2003.
www.wolf.org. International Wolf Center Web Site.
www.fws.gov/redwolf. Red Wolf Recovery Program Web Site.
www.redwolves.com. Red Wolf Coalition Web Site