The wolf species contains but is not limited to; Dingo, Gray Wolf, Ethiopian Wolf, Red Wolf, Mexican Wolf, Arctic Wolf, Eastern Wolf, Eurasian Wolf, Italian Wolf, Tundra Wolf, Arabian Wolf, Caspian Sea Wolf, Egyptian Wolf, Great Plains Wolf, Indian Wolf, Mackenzie Valley Wolf and Russian Wolf.
However, we will look primarily at the Gray Wolf, as this is the most common wolf and contains in itself a wide variety of sub-species, all of which may occur as theriotypes. Wolves don't vary much in anatomy, but rather in size and fur. Variations in species and fur colour can be seen in the photo album 'canines'.
In general, Gray Wolves measure from 66 to 96 cm at the shoulder and 102 to 147 cm from the head to the base of their tail. Tail length measures from 33 to 51 cm. A wolf's average weight ranges from 27 to 45 kilograms; however, some wolves have been recorded in extremes of 18 to 80 kilograms. Bitches generally weigh 20% less than dogs.
The gray wolf is a slender, powerfully built animal with a large, deeply descending ribcage and a sloping back. Its abdomen is pulled in, and its neck heavily muscled. Its limbs are long and robust, with comparatively small paws. The front paws have five toes each, while the back paws have four. The forelimbs are seemingly pressed into the chest, with the elbows pointed inward, and the feet outward, thus allowing both fore and hind limbs on the same side to swing in the same line. The wolf's legs are moderately longer than those of other canids. This enables the animal to move swiftly, and allows it to overcome the deep snow that covers most of its geographical range. Females tend to have narrower muzzles and foreheads, thinner necks, slightly shorter legs and less massive shoulders than males. Compared to its smaller cousins (the coyote and golden jackal), the gray wolf is larger and heavier, with a broader snout, shorter ears, a shorter torso and longer tail.
A wolf usually travels at a loping pace, placing its paws one directly in front of the other. This gait can be maintained for hours at a rate of 8–9 km/hr, and allows the wolf to cover great distances. On bare paths, a wolf can quickly achieve speeds of 50–60 km/hr. A running wolf holds its head slightly low and cocked to one side, directing one ear forward and the other back. This posture allows the wolf to continually make use of its exceptional hearing.
The narrow collarbones, interlocked foreleg bones and specially adapted wrist-bones give the wolf streamlining, strength and speed. The radius and ulna bones are 'locked' in position. This inability to rotate the forelimbs gives superb stability when running.
The colour of wolf 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.
Generally, wolves have dense and fluffy winter fur, with short under fur and long, coarse guard hairs. The longest hairs are found on the back, particuarly the ruff. The hairs on the cheeks are elongated and form tufts. The winter fur is highly resistant to cold; and wolves in northern climates can rest comfortably in -40° by placing their muzzles between the rear legs and covering their faces with their tail. Wolf fur provides better insulation than dog fur, and does not collect ice when warm breath is condensed against it. In warm climates, the fur is coarser and scarcer than in northern wolves. Female wolves tend to have smoother furred limbs than males, and generally develop the smoothest overall coats as they age.
It had been suggested that although fur colour is not used for camouflage, blended colours do help emphasise tactile communication.
The gray wolf's head is large and heavy, with wide a forehead, strong jaws and a long, blunt muzzle. The ears are relatively small and triangular. The teeth are heavy and large, being better suited to crushing bone than those of other extant canids, though not as specialised as those found in hyenas. The canine teethare robust and relatively short (26 mm).The wolf can exert a crushing pressure of perhaps 1,500 lbf/in2 compared to 750 lbf/in2 for a German shepherd. This force is sufficient to break open most bones. In cold climates, the wolf can reduce the flow of blood near its skin to conserve body heat. The warmth of the footpads is regulated independently of the rest of the body, and is maintained at just above tissue-freezing point where the pads come in contact with ice and snow.
The wolf's face is heavily involved in communication. The eyes, when open wide or directly staring are aggressive, but when looking away or closed to slits show fear and submissive behaviour. Any one of the following detonates aggression or dominance in a wolf; ears erect and forward, mouth open, canines bared, tongue retracted, muzzle shorterned (skin folded), held held high and neck arched. In contrast, the following shows sumbmission and/or fear; ears flattened and turned to the side, mouth closed, canines covered, tongue extended, nose lengthened, head lowered and neck extended.
The gray wolf is almost always monogamous, with mated pairs staying together for life unless one of the pair dies. Upon death, pairs will be quickly re-established. The exception to this are 'Casanova' wolves; who upon leaving their family pack cannot find a mate, and so instead mate with female wolves from other packs, forming no social bond with them. This means some packs have more than one breeding pair.
Females are capable of producing pups every year, with one litter annually being the average. During pregnancy, female wolves remain in a den located away from the peripheral zone of their territories, where violent encounters with other packs are more likely. Old females usually whelp in the den of their previous litter, while younger females typically den near their birthplace. The gestation period lasts 62–75 days, with pups usually being born in the summer period.
Birth in wolves is much the same as it is in dogs; an obvious distinction being that while dogs have multiple seasons, wolves can only produce one litter a year. Pups are born from late March to early May. Birth often coicides with that of the main prey species, creating an abundance of food which helps when there are extra mouths to feed. Climate also plays a timing factor, with wolves south towards the equator giving birth earlier and arctic wolves giving birth sometimes as late as June. With an average litter of five or six, wolves bear relatively small litters but larger pups than other canines. Larger pups may be resistant to cold, wet weather but they also require more nutrition from their mothers.
The pack plays an important role in caring for the young. Pups are supported indirectly by the father, who defends the home site as well as increasing hunting activity to provide the mother with food. Later the parents and other relatives provide the pups' food, although some studies have found other pack members to be half as likely to regurgitate food for the pups than parents.
Single mothers and even fathers have been observed to successfully raise pups but assistance may increase the likelihood of survival. The help provided by other pack members decreases the necessary exertion of the parents in obtaining food. This allows them more time to protect and care for the pups. Mothers are permitted to spend lots of time at the den especially during important times such as cold nights when the pups need to be kept warm.
After about three months, the parents activity gets back to normal and the pups can be left safely at rendezvous sites.
There are a number of theories for why non-breeding family members provide assistance with pup rearing. One of the most obvious ones is genetic survival. Providing the parentage is the same, the last years offspring will share as much of their genetics with their siblings as they do with their own offspring. The pups are the future of the pack so helping them may yield benefits in future hunting success and minimise loss of food to scavengers. Juvenile animals are still learning and would be inexperienced parents so by sticking around to learn how to raise offspring they may increase their own future success. Whatever the motivations, the system works.
Development in wolves is similar to that in dogs. There are four key stages of development to maturity:
Wolf pups are born with their eyes tight shut and have many similar features that are maintained to adulthood in some of our modern dog breeds: their ears are floppy and faces squat with the heads generally having a rounded appearance. The fur is often dark and the pups are capable of little more than crawling around like little heat seeking missiles. The pups suckle as a reflex within hours of birth, relying heavily on their sense of touch and smell. Mothers provide warmth and nourishment as well as cleaning pups and consuming eliminations, in order to keep the den clean from mess. Routines do begin to form but behaviour is generally very simple at this age with some basic vocalisations such as crying when hungry or cold. Ideally during this period other pack members will be around to bring food to the mother.
Usualy pups' eyes open somewhere between 12 and 14 days and are blue. They progressvely change to the characteristic yellowy orange by eigth to sixteen weeks of age. Once their eyes are open pups begin to stand and walk for short periods. They steadily become bolder - exploring further towards the den's entrance and eventually brvaing short ventures out into the outside world. Once they begin to lose their uncertainty they can be found hanging out at the mouth of the den. Muscles, co-ordination, size and senses develop rapidly at this stage. Pups learn to recognise familiar individuals and even begin to understand some vocalisations during the rapid learning of the transition and socialisation periods. The stage is set for sociality and learning during later life.
After 20 days or so when the pups are exploring the mouth of the den they begin to interact and elict care from other pack members. They also begin to wean to solid food. As they get older they venture further and interact more and more with the adults. When needed the mother carries the pups to safe areas or alternative den sires, but as they mature they begin to follow the nursing mother if she is disturbed during feeding. This behaviour later evolves into following any pack member making an assertive departure. once they are five weeks old this enables the pack to move the pups between home sites. At this age they are still small enough to be carried but large enough to travel short distances (usually less than 0.5km)
The senses become fully developed and milk teeth enable the pups to chew small pieces of meat. Suckling bouts become shorter and intervals between feeds longer. Sharp milk teeth quickly encourage the mother to wean the pups to solid food. By ten weeks, soilciation of milk almost completely stops and pups begin to focus their attentions on whichever pack member appears bearing food. The classic 'lick up' behaviour of rubbing and licking an adult's muzzle to stimulate food regurgitation is also maintained as an appeasement gesture into adulthood. At this age, pups are capable of following adults to kill sites and searching around home sites for cached food.
The socialisation period is pivotal in a wolf's behavioural development. Their experiences at this stage help form and shape the bonds and associations they will have with their environment and social interactions. Pups learn to interact with each other and the pack. Levels of activity such as play increase, building fitness and rehearshing many movements and routines that will become useful later in life.
The longest period lasting from 12 weeks up to maturity is another crucial learning phase. Social skills ahve already become highly developed but the need to provide for themselves becomes more important with age. From the moment pups begin following adults departing their home site they begin to build on their innate abilities and develop associations with the scenarios presented to them. Chasing and capturing small moving animals appears pre-programmed as it occurs without practice or teaching. How and where to take down large prey safely, however, is something that must be learnt and perfected. Although still not fully grown, juveniles join hunts between four and ten months old. Adult teeth are present by six to seven months. Hunting skills become perfected through practice and necessity as getting first dibs and provisions from other pack members starts to cease.
Juveniles tend to act in a modest manner towards adult pack members. Older wolves effectively intimidate and discipline younger wolves but litter mates may squabble over food or during play.
Conflicts are more likely between members of the same sex, particuarly during the winter periods of heightened hormone activity. Food resources play an important factor in the social tolerance of maturing juveniles. Food sharing appears to be conditional, affected by prey availability, maturation rates and social conditions. When packs remain larger (usually under the conditions of abundant food and larger prey) juvenile dispersion is caused by sexual competition, incest avoidance and breeding suppression by older pack members. Death and disease, fights with neighbouring packs and hunting by humans further disrupt stability adding to the dynamic forming and dissolving of family packs. Such factors can give non-dispersing offspring or siblings the prospect of territory inheritance and breeding opportunity.
There appears to be a trade-off between the risk and benefits of dispersal or remaining with the pack. However, sometimes between nine months and three years of age most wolves will usually disperse from their natal pack. Finding a mate and a territory to begin a new pack or being accepted as step-parents in a disrupted pack may take several years. The risks of lone hunting, conflict with other packs and traffic collisions all make dispersal a difficult period in any wolf's life but if sucessful, the benefits are numerous.
-Pete Haswell, BSc Hons Environment Science.
Wolves can communicate visually through a wide variety of expressions and moods ranging from subtle signals, such as a slight shift in weight, to more obvious ones, such as rolling on their backs to indicate complete submission.
Although some wolves are solitary, most are highly sociable animals. The basic social unit of a pack is the mated pair, accompanied by the pair's adult offspring. In ideal conditions, the mated pair produces pups every year, with such offspring typically staying in the pack for 10–54 months before dispersing. The average pack consists of a family of 5–11 animals (1–2 adults, 3–6 juveniles and 1–3 yearlings), or sometimes two or three such families, with exceptionally large packs consisting of 42 wolves rarely occuring.
New packs are normally formed by an unrelated male and female who have both left their family packs. Wolf packs rarely adopt lone wolves, and when they do the adoptee is normally young, between one and three years old.
During times where there is lots of prey, wolf packs may temporarily join together to form larger packs. Large packs always occur when there ie plentiful food and optimum conditions.
Wolves naturally organize themselves into packs to maintain stability and assist with hunting. The pack leader isn't necessarily the alpha male. The alpha female takes the reins in certain groups since wolf rankings are based on strength and the ability to win fights and settle arguments, not gender.
The beta wolf comes next. Beta wolves act as the second in command, taking over if the alpha male dies and possibly remating with the alpha female. When an alpha grows weak or too old to effectively lead the pack, the beta wolf may challenge him or her to a winner-take-all brawl.
On the bottom rung of the ladder, you have the omega wolf. As the name implies, the omega wolf is the weakest and the least cared for in the pack. Bullied by other members, the omega wolf will receive the brunt of the aggression in the wolf world, particularly during inter-pack fighting. The may not be physically the weakest, but they are the most naturally submissive.
A wolf hunt can be divided into five stages:
The actual killing method varies according to prey species. With large prey, mature wolves usually avoid attacking frontally, instead focusing on the rear and sides of the animal. Large prey, such as moose, is killed by biting large chunks of flesh from the soft perineum area, causing massive blood loss. With medium-sized prey wolves kill by biting the throat, causing the animal to die within a few seconds to a minute. With small, mouse-like prey, wolves leap in a high arc and imobilize it with their forepaws. When prey is vulnerable and abundant, wolves may occasionally surplus kill.
Once prey is brought down, wolves begin to feed excitedly, ripping and tugging at the carcass in all directions, and bolting down large chunks of it. The breeding pair typically monopolizes food in order to continue producing pups. When food is scarce, this is done at the expense of other family members, especially non-pups. The breeding pair typically eats first, though as it is they who usually work the hardest in killing prey, they may rest after a long hunt and allow the rest of the family to eat unmolested. Once the breeding pair has finished eating, the rest of the family will tear off pieces of the carcass and transport them to secluded areas where they can eat in peace. Wolves typically commence feeding by consuming the larger internal organs of their prey, such as the heart, liver, lungs and stomach lining. The kidneys and spleen are eaten once they are exposed, followed by the muscles. A single wolf can eat 15–19% of its body weight in a single feeding.
Wolves communicate in a variety of different ways using auditory, chemical, visual and tactile signals. Most communication is between pack members, although communication also takes place between different packs, and occasionally between packs and lone wolves.
Smell - Olfactory communication
Wolves have a very keen sense of smell far greater than humans, with approximately 200 million olfactory cells housed in the nose. Through research, scientists have been able to determine that they can detect their prey at distances of up to 3 kilometres (1.75 miles).
Urine, faeces and special scent glands in the feet at used to mark a pack's territory. These sign posts tell lone wolves and neighbouring packs that the area is occupied. By smells produced through secretions in the wolf's skin, urine and faeces, wolves can tell the gender, breeding condition, social status, age, condition and diet of each other. Each scent gland in the body is thought to play a different role.
Scent-rolling is a behaviour that has a number of theories about it's existance. These include an effective way of covering the wolf's own scent, familiarisation with a new scent or just a strong attraction to a novel smell. The smell is usually rubbed on to the side of the neck and shoulder, any novel smell can stimulate this response.
As scent is the wolf's best sense it plays a major part in both short range and long range communication.
Body Language - Visual Communication
Visual signals are every bit as important as the olfactory and auditory signals. The whole body is used in this form of complex communication. Visual signals can be used to show affection towards others as well as happiness, distress and fear. Visual communication can also create respect between pack members. Body language amongst wolves is frequently described as dominant or submissive, although neutral behaviours have also been described.
Submissive body language falls into two catergories; passive and active. Passive submission is generally a reaction to being approached by a more dominant wolf showing heightened aggression, for example in breeding season. The submissive wolf will lay partly on its back and side while the other wolf sniffs, stands over or shows dominance in a more aggressive manner.
Active submission on the other hand is often used in greeting and bonding and is much more frequent than passive submission. The subordinate wolf will excitedly lick, hold and smell the mouth of the dominant wolf. A dominant animal is aloof and can control the pack through posturing, grow in stature, with stiff legs, raised hackles as well as higher than usual head and tail carriage. Different facial expressions are also included in visual communication.
Sound - Auditory Communication
The howl is probably one of the most recognisable forms of communication when we think of the wolf. This vocalisation has the ability to travel long distances up to 10 miles, depending on weather conditions and terrain (although 6 miles is average). However there are other forms of auditory communication that can be easily forgotten, these include: growling, whining, barking, squealing, humming and whimpering; as well as the yelp, moan and snarl. Each of these different sounds have different meanings, for example; a bark can be used to warn pack members of approaching danger. These sounds can be grouped together to intensify the communication e.g. a whimper-yelp or bark-growl-snarl.
These vocalisations are different dependant on the age of the wolf. Cubs can vocalise from a very early age, the most common type of vocalisation for neotonal wolf cubs signify distress, pain and hunger. Volcalisations develop as the cub grows during which time they lose some of their earlier vocalisations but gain others. It can take a cub up to 6 months from birth to develop a full adult vocal range. Vocal signals can aid the effectiveness of visual signals, for example a dominant wolf may use growls or snarls when asserting leadership. Reasons that wolves may howl include: notifying other pack members of their location; informing other packs of where they are to aid in spacing or territory marking, to attract a mate, reassemble a scattered pack and rally the pack before a hunt. Although it is not scientifically proven many people believe there is a social bonding element to the howl.
Touch - Tactile Communication
Tactile communication takes place alongside other forms of communication especially visual communication. It takes the form of actual bodily contact, which with adult wolves is seen during greeting, social interaction and play. The behaviour of mutual grooming also falls into this catergory of communication. Cubs are often seen huddling together, this behaviour starts whilst they are neonates when they will 'root' out each other and their mother in the den before they have the ability to see one another. Tactile communication can frequently be seen taking place between the alpha pair during breeding season as they will spend time lying together, performing mutual grooming.