|
Running With The Wolves
Wolf Information & Awareness
Center
"Wolf Anatomy"
Article by Wolf Howl Organization
 |
Height and Weight
In general, Gray Wolves measure from 66 to 96 cm
(26 to 38 inches) at the shoulder, and from 102 to
147 cm (40 to 58 inches) from head to the base of
their tail. Tail length measures from 33 to 51 cm
(13 to 20 inches). A Wolf's average weight ranges
from 27 to 45 kilograms (60 to 100 pounds); however,
some Wolves have been recorded in extremes of 18 to
80 kilograms (40 to 175 pounds). Female Wolves
(called bitches) generally weigh 20% less than the
males (called dogs). |
 Wolves are covered in a
moderate length pelt across most of their body. The
color of their fur may range from pure black to pure
white, with any tint or shade of gray, tan, cream,
ochre (yellow-gold), sienna (reddish brown), and brown
between. On Wolves having light and dark patterned
fur, the markings tend to be lighter on the ventral
(belly) side of the body and graduate to
darker/longer/thicker fur on the dorsal (back) side.
The ears, forehead, and top of the muzzle are usually
of a short/course/lighter fur, mingled of dark and/or
mid pelage tones with the underside of the muzzle and
throat being of lighter pelage tones. The legs and
paws also have short/course/ lighter fur. The tail is
generally covered with a long/thick/bushy fur, the
color scheme being similar to that of the rest of the
Wolf; dark on top and lighter on the bottom. Light
colored Wolves may even have a dark spot of fur
covering the precaudal scent gland, also called the
violet gland, at the top of their tail, about 10 cm (4
inches) from its base and on the tip. |
In the wintertime a
Wolf's pelt usually grows quite thick to keep the Wolf
comfortable at cold temperatures. During this time the
pelt fills in with a short, dense, under-growth of
fine, or downy, light colored fur. This is sometimes
called a "prime coat." In spring this fur is then
shed, thinning the pelt dramatically to prevent the
Wolf from over-heating as summer temperatures rise.
Some call this thinning of the pelt "blowing" or
"blowing-out" the coat.
Some Wolves, especially
dark furred Wolves, have phases where their pelt
lightens significantly during certain seasons or as
they age. A black-phase Wolf starts life with a very
dark or black pelt which may become lighter in the
summer and then darken again in the winter. A dark or
black-phase Wolf's fur also tends to lighten with age
and may become light gray, or even white, as the Wolf
reaches his or her senior years.
Wolves are
generally born with dark or black fur which lightens
as they mature. It is unlikely that Wolves are subject
to albinism, as no living examples exist. |
|
Eyes and
Vision
Wolves
are usually born with deep blue eyes which lighten and
then gradually fade into the adult eye color over the
next six to ten weeks. A mature Wolf's eyes are often
amber/brown or gold, but also commonly come in hues of
brown, gray, yellow, and green. It is interesting to
note that puppies are born with blue eyes, while
mature Wolves do not retain blue as an eye color.
Huskies often have blue eyes, and because of this
people think there must be blue eyed Wolves as well,
but this isn't true. If you see a Wolf with blue eyes
then he or she is likely a Wolf-hybrid and not a
full-blooded Wolf.
A Wolf's eye sight is just about as good as that of
a human being. However some experts believe that
Wolves may be nearsighted because their eyes lack a
foveal pit, an indentation in the retina which
provides for focusing, especially on distant objects.
Wolves have excellent peripheral vision and their eyes
are optimized to detect motion. In addition, they have
a very high ratio of rods (grayscale receptors) to
cones (color receptors) in the retina; in fact, about
95% rods. This abundance of rods aids the Wolf in the
ability to see at night. A Wolf's night vision is far
superior to that of a human being.

Although little research has been done into a Wolf's
ability to see color, it is believed that they may be
partially color blind. Wolves have only red and blue
photo receptors in their eyes, unlike humans, who have
red, green, and blue photo receptors. Tests on
domestic canines show that they may not be able to
distinguish yellow from green or orange from red.
Tests on Wolves, where red, blue, yellow, and green
dyes were put onto clean snow, show that they often
detect the red and yellow stains. This could be
because they associate these colors with blood and
urine and have little interest in the other colors.
There is no conclusive evidence regarding the color
vision abilities of Wolves, however. It is my personal
belief that Wolves can see all of the colors, but only
take an interest in those that might benefit them in
some way.
Canines have a third eyelid (nictitans) which
stretches across the eye and contains a gland which,
along with glands in the ciliary body, acts to
lubricate the eye. However, these tear glands excrete
an oily substance rather than watery tears: Canines
are not able to shed the moist tears of sorrow as
humans do, but this doesn't mean they don't cry. |
|
Ears and
Hearing
A
Wolf's ears are triangle shaped and rounded across the
top; they are much broader and shorter than coyote or
fox ears. Wolves tend to have shorter/darker fur on
the backside of the ear, with a lighter, somewhat
longer fur along the inside. Wolves are able fold
their ears back against their head, move them side to
side, and forward independently of each other. This
range of motion assists the Wolf in detecting the
direction of sound quite precisely. Wolves also use
ear postures for communicating amongst themselves.
Hearing is a Wolf's second most developed sense. It
is thought that domestic canines can hear sixteen
times better than human beings. It is supposed that a
Wolf's ability to hear is even better than this.
Experts believe that Wolves may be able to hear
frequencies far above the limits of human beings. The
upper limit of human hearing is about 20 kHz, a Wolf's
upper limit has been estimated at between 25 and 80
kHz. Wolves have been known to react to imitated Wolf
howls from five kilometers (three miles) away. Some
experts say that a Wolf can hear ten to sixteen
kilometers (six to ten miles), depending on the
density of trees and other obstacles between them and
the source of the sound. |
|
Nose,
Tongue, Taste, and Smell A Wolf's nose is composed
dark or black, rubber-like, tissue at the end of the
muzzle and above the lip, with a pair of nostrils
leading to the nasal cavity which lie above the hard
palate of the mouth. The nose is the only part of the
canine body that "sweats," as there are no sweat
glands in the skin. The nose gets wet and cold as the
Wolf exercises in order to cool the blood flowing
through the muzzle and facilitate a constant body
temperature.

The sense of smell is a Wolf's most developed sense
and greatest asset. A domestic canine's nasal cavity
has about twenty-five times the number of olfactory
receptors and fourteen times the scent receptive
surface area of a human being. It has been suggested
by experts that a Wolf may have twelve times the
ability to detect odors of a domestic canine and a
hundred times that ability of a human being.
The sense of smell plays a very important role in
lupine life and society. Not only is it the means by
which Wolves detect and locate pray, but it is
instrumental in a variety of other tasks. A Wolf's
body has scent glands (see the Scent Glands section)
that tell a Wolf's health, mood, and identity to other
Wolves. Upon meeting, Wolves will smell each other's
muzzle, anus, and tail to make sure they know who the
other Wolf is, and also learn details about health,
mood, where the Wolf has been, and what she/he has
been eating. Wolves use urination, called marking, to
mark their territories so other Wolves may know they
are crossing into another pack's land by smelling the
marks.
A Wolf's tongue is long and quite soft. It is
covered in hundreds of projections called papillae
which aid in grooming and with tugging meat from
bones. A Wolf also uses the tongue for licking up
blood, drinking water, and during certain social
rituals where tongue contact indicates respect and/or
submissive behavior. The tongue is quite thick, but
tapers to a thin tip that can be curved into a
ladle-like form, making it especially useful for
lapping up water.
It's difficult to know exactly what another animal
is able to taste, but it is known that canines have
taste receptors that permit them to know the
sensations of sweet, salty, bitter, and acidic. |
|
Teeth,
Fangs, and Jaws
A Wolf has 42 teeth: the upper jaw has six incisors;
for cutting flesh, two canines (also called fangs);
for piercing into flesh and holding prey, eight
premolars and four molars; for slicing and grinding.
The lower jaw has six incisors, two canines, eight
premolars, and six molars. The last premolars on the
upper jaw and the first molars on the lower jaw are
called the carnassial teeth; specialized for slicing
through meat. The canines may reach a length of 5.7
centimeters (2.25 inches), which includes the area set
within the jaws.
Experts have surmised that Wolves are capable of a
jaw pressure of up to 105 kilograms per square
centimeter (1,500 pounds per square inch). This is
about twice the jaw pressure of a German shepherd. |
|
Paws, Legs,
and Movement Wolves have long, strong legs and large
paws; they are built for speed and agility. The
forelegs appear pressed into the Wolf's narrow chest,
with the elbow turned inward and the paws turned
outward. This allows the Wolf's fore and hind legs to
swing in a strait line so that the hind paw falls into
the impression that the front paw left. Domestic
canines generally leave the hind paw impression next
to the forepaw impression. The Build of a Wolf's legs
are ideal for fast, agile movement over all types of
terrain, even deep snow. And the webbing between their
toes makes Wolves excellent swimmers as well.
As
with other canines, Wolves are digitigrade; meaning
they bear their weight on their toes as they walk and
not the entire sole of the foot. There are four toes
on each hind paw, and five toes on each forepaw.
However, one of the toes on the forepaw is used for
clasping and doesn't touch the ground. Each toe has a
calloused pad and a non-retractable claw. Also, each
paw has a single large calloused heel pad. An adult
Wolf's forepaw prints measure from about 11.4 to
centimeters 12.7 (4½ to 5 inches) in length and from
about 9.5 to 11.4 centimeters (3¾ to 4½ inches) in
width, with their hind paws measuring 15 to 20%
smaller then their forepaws.
As average gait of a Wolf is between 6.5 and 8
kilometers (4 and 5 miles) per hour. Wolves can
maintain an average top speed of about 40 kilometers
(25 miles) per hour over a distance of 3 kilometers (2
miles). A Wolf maintaining a speed of 56 kilometers
(35 miles) per hour over 6 kilometers (4 miles) was
reported by a Minnesota game warden in 1955. There
have been other reports of Wolves running in excess of
56 kilometers (35 miles) miles per hour, but these are
likely exceptional extremes. Wolves bound when they
are in pursuit of large prey animals. L. David Mech
reported that he witnessed Wolves bounding over 5
meters (16 feet) while in pursuit of moose. Wolves can
keep up the chase for about twenty minutes, after
which they tend to rest or sleep for at least ten to
fifteen minutes before resuming activity.
It's not uncommon for a Wolf to travel 32 to 48
kilometers (20 to 30 miles) a day while hunting. Where
food is scare Wolves have been recorded to have walked
190 kilometers (120 miles) searching for food in a
single day. Wolves have a great capacity for long
journeys. When dispersing from their pack, lone Wolves
have been monitored traveling over 800 miles in search
of new territory. |
|
Anus,
Genitals, and Tail A Wolf's anal region not only
serves the usual function of defecation, but also
plays an important role in communication. To the lower
left and right of the anal sphincter are the anal
scent ducts. The exact purpose of these "scent glands"
is uncertain, but it is theorized that they produce a
potent scent unique to a given Wolf and are employed
in scent marking and in greeting ceremonies for the
purpose of establishing the identity and status of a
given Wolf. In the communications section you will
find more information on the role these glands play in
lupine social life.

The
male genitalia consist of a fur covered
scrotum, composed of thin, dark colored
skin. The scrotum surrounds the testicles
and is designed to keep the testicles
several degrees cooler than the Wolf's
internal body temperature so that the
sperm are not damaged by excessive warmth.
From the scrotum extending along the lower
belly is the prepuce, often called the
sheath. The prepuce is a flap of fur
covered flesh that sheaths and protects
the penis. The penis
 is a soft fleshy
organ which extends from the sheath as it
pumps full of blood when the Wolf becomes
sexually aroused. The penis contains a
bone called the Baculum Bacula (OS penis),
which aids in penetrating the female's
vulva during copulation. When canines mate
the male's erection occurs after
penetration, rather then before (to
achieve) penetration as in humans.
Toward the base of the penis is the bulbus glandis, also
called the knot, which swells into the
female's vagina to tie the male and female
together during coitus. The knot prevents
the mating pair from parting until after
insemination has taken place. In addition
to mating function and urination, the
penis is also used to scent mark; it is
believed that the urine contains a
pheromone, or scent, unique to the
individual Wolf and that other Wolves
smelling this mark can easily identify the
Wolf from whom it came from. Out of mating
season a male Wolf's testicles tend to
shrink, accompanied by the loss of sexual
appetite.
|
The female genitalia are mostly
internal. The external labium
(lips) of the vulva occupies 
approximately the same physical
location on the body as the
scrotum would on a male. In the
wintertime, when the female
enters estrus, the vulva becomes
hot and puffy (hence the term
"in heat"). This puffy/swelling
makes the female visually
interesting to males, and along
with the pheromones produced in
the vagina, indicates when the
bitch is physically ready to
mate. The puffy vulva is also
ideally shaped so that the tip
of the male's penis can easily
hook into its fold to be
directed into the vagina during
copulation. During copulation
the male thrusts his penis into
and out of the female's vagina
while shifting his weight from
one leg to the other in order to
work his bulbus glandis into
her. This locks the male's penis
into the female's cervix, which
undulates to stimulate his penis
to erection. Erection expands
the bulbus glandis and ties the
two Wolves together; thus coitus
is
 |
achieved. Once coitus is
achieved, the female's vaginal
sphincter muscles tighten around
the male's bulbus glandis to
hold it firm as she pulls
forward, triggering ejaculation
of semen into the uterus. In the
initial 30-50 seconds of the
tie, the male deposits only
clear semen until orgasm is
achieved. During the initial 30
seconds or so of orgasm, a
cloudy, somewhat thicker, sperm
bearing semen is ejaculated;
thus insemination is achieved.
After insemination the semen
returns to a clear state, but
continues to pump forth until
the end of the tie, which may
last up to 35 minutes.
Additional information about
courtship and mating can be
found in the procreation
section.
A Wolf's tail
measures from 33 to 51 cm (13 to
20 inches) and consists of long
fur radiating away
from it in all directions, but
sloping toward the tip. Most
Wolves have a dark spot of fur
covering the precaudal scent
gland, also called the violet
gland, about 10 cm (4 inches)
from the croup and on the tail's
tip. The tail serves to protect
the anus and genitals from
insect bites as well as a device
for communicating with other
Wolves. The communications
aspect of the Wolf's tail will
be delved into in the section
dealing with communication.
|
Scent Glands
There
are various scent
glands located across
the Wolf's body which
are used for
communication of
identity, mood, and
health. Scent glands
are located on the
anus, the top of the
tail, behind the ears,
and on the cheek near
the corner of the
mouth. In addition,
the penis and vagina
also function as scent
glands during
urination marking.
Anal scent glands,
located to the left
and right and below
the anal sphincter,
produce a pungent oily
pheromone that is
excreted during bowel
movements, thus
scenting the Wolf's
scat with his or her
unique odor. The
purpose for this is
unknown, but it is
believed that the anal
scent glands play an
important role in the
identity of Wolves,
for high ranking males
often lift their tails
during greeting
ceremonies, whereby
both Wolves sniff each
other under their
tails, before they
accept each other.
Submissive males and
females of any rank
usually do not greet
this way, and will
tuck their tail to
avoid attempts to know
them this way. The
exception to this is
when the dominant
female enters estrus,
at which time she will
lift her tail to a
ranking male, so that
he may know she is
receptive to mating.
Another major scent
gland, called the
precaudal gland or
violet gland, is
located near the top
of the tail, about 10
cm (4 inches) down
from the croup. Again
the actual purpose of
this gland is unknown,
but it is believed
that the oily bluish
pheromone it produces
may indicate a Wolf's
mood or level of
sexual receptivity
during mating season.
There is little
information available
for the scent glands
below the ears and on
the cheeks, except
that they are sniffed
during greetings and
sometimes nuzzled
during active
submission displays.
|
Home
|
Back
|
Top of Page |
|
| | |
|