The Wolf Pack
Wolves are gregarious animals who mostly live in packs. A pack starts when a male and a female wolf meet each other and start going around together. As a mated pair they find a territory to settle on and raise cubs most years. Their cubs stay with them until they are old enough to leave home, usually by the time they are three years old, and conditions are right to start a family or pack of their own. Thus you can view a pack as a permanent core of a mated pair plus their continuously dispersing offspring.
Command & Control
Command and control in a wolf pack is in many ways similar to a human family. It is the parent wolves who exercise authority. Because they dominate the behaviour of the other wolves in the pack they are often referred to as the alpha male and the alpha female (see Alpha Wolf).
The alpha wolves are the oldest and most experienced members of a pack and it is generally to every family member's advantage to do what they bid. The alpha wolves tend to start and guide most family activities. They lead the pack when travelling, decide when and where to hunt, are usually the first to attack strange wolves, and tend to attack the most vigorously when encountering a hostile wolf pack.
Alpha Privileges
Control of breeding rights is one of the key privileges held by alpha wolves. Alphas are usually the only wolves in the pack to breed and they actively prevent other adult wolves in the pack from breeding. If the other adults want to breed they usually have to leave their pack and set up elsewhere.
Another important privilege concerns food. When a large prey animal is brought down, the alpha wolves control access to it. They make sure they and their dependent cubs eat enough before their older offspring start feeding seriously. In lean times the other adults may do better to quit their pack and fend for themselves. However, wolves tend to feed amicably when food is ample.
An Early View Of Pack Social Organisation
The first studies of social relationships within a wolf pack were based on unrelated captive wolves, because wolves in an enclosure are far easier to observe than wild free-living wolves.
In a captive group of unrelated wolves there is a tendency for a social - or 'dominance' - hierarchy to emerge. The idea of a hierarchy was first described for captive wolves in 1947 and tended to overshadow other attempts to understand the social interactions within a pack. This early view of a wolf pack is that the wolves are forever struggling to get further up the social hierarchy, ultimately to the alpha position, while holding in check everyone else (see Early View).
The problem with this early view of wolf pack society is that it is based almost entirely on observations of captive wolves. Captive groups of wolves are usually collections of individuals from different origins and backgrounds, and their living conditions are artificial and imposed on them. Studies like these may reveal insights about wolf pack society, such as range of flexibility and adaptability, but are limited in what they can tell you about the social relationships and behaviour of naturally forming wolf packs in the wild. It is a bit like observing only the inmates of prisons when you are trying to understand human society, then extrapolating your findings to free-living people.
When wolf packs were seriously studied in the wild they turned out to have a familial structure and the emphasis of a dominance hierarchy was exposed as somewhat over done. However, the term 'alpha' wolf has stuck and is still used to describe the highest ranking male and female wolves of a pack.
How Packs Originate
The cubs of a pack disperse when grown to find a mate of the opposite sex and raise a family of their own. A dispersing young wolf probably explores a number of areas searching for signs of wolf pack occupancy. An area covered in wolf scent marks will be occupied by a wolf pack. An area free of wolf scent marks will be vacant and might make a good territory. A young wolf keeps searching until another lone wolf of the opposite sex is found doing the same thing.
When a male and female are attracted to one another they court and attempt to form a pair bond. Courtship is not always successful, canids have preferences, as humans do, but if they remain together they will travel about and try to set up a territory. If they succeed they will mate and a new wolf pack will grow.
Factors Influencing Pack Size
The smallest pack is a newly bonded male-female pair. Pack size grows according to the number of cubs a pair bear, how many cubs survive to adulthood, and how long offspring stay with their parents. Wolf litters average five or six cubs per litter. So if the pack breeds most years and just some of the young survive and do not disperse, a new pack can increase in size quite quickly.
Pack size also depends on time of year. New cubs are born in spring, so pack size is at a maximum in the summer when the cubs are old enough to join the adults on the hunt and keep up with them. Packs reach minimum size in the winter and before the next breeding season when death and dispersal of wolves from the pack reduce their number.
Food is an important factor. The more food a pack can obtain, the more cubs survive and do not die of starvation or ill health. Packs tend to have more members where prey are large and numerous and can therefore support more wolves. Packs break up and individuals disperse or packs do not grow large in the first place when there is insufficient food.
Wolf density and the corresponding availability of space for packs to establish territories in are important factors. When wolf population density is low (other things being equal), it is a good time for adult offspring to leave their natal packs and make their own way in life, so pack size will decrease. Conversely, when a region is saturated with wolves, adult offspring tend to delay leaving home and pack size grows when more cubs are born and in turn delay living home.
How Big Are Wolf Packs?
In places in Europe packs can average about five to seven wolves. They are under heavy human control superposed on existing environmental pressures, so larger packs are rare. In Minnesota, the US state with the largest wolf population outside Alaska, packs are usually around five to ten strong. Packs in Alaska commonly number six to twelve wolves.
The biggest wolf packs are reported in Alaska and across the border in Canada, where occasionally exceptionally large packs of around thirty wolves are seen. However, the world record may go to a pack of 37, including 21 cubs from three litters, in Yellowstone National Park, Wyoming, not long after wolves were reintroduced there. That is a peculiarly large pack.
The Arctic might generally claim the smallest packs, presumably because of the scarcity of food.
Pack Break Up & Splitting
If one or both parents of a pack die their pack may fall apart. When a pack breaks up, the space it occupied becomes vacant and may be taken over by neighbouring packs or by a new pair of wolves wanting to establish their territory.
As noted above, a wolf pack forms when two dispersing wolves meet and breed. Another, though less common way, for a pack to come into existence is when a pack splits into two new packs. Pack splitting might happen when a pack is too large for all the wolves to get on well with each other. Or a pack might split if it is to large for all the members to get an adequate meal even after successful hunts. Another impetus for pack splitting is when a strange wolf joins a pack and breeds with one of the pack's adult offspring. Then when the pack gets too large the two sets of families part company. When a pack splits, the original territory may be divided between them.
Adoptions
The adoption of an apparently strange wolf by a pack is known to happen from time to time. Why should a family of wolves take in a lodger? It is probable that some incoming wolves are actually related wolves returning home, having failed to disperse successfully. However, some incomers are probably unrelated strangers.
How could a pack benefit by an adoption? A small pack might benefit with an additional member on the hunt or for defending its territory from encroachment by larger neighbouring packs, provided the food supply is adequate to feed another mouth. An adoption might work by introducing new genes from an unrelated wolf to counter the affects of any inbreeding in a long-lived pack. Or an unrelated wolf might prevent the pack from falling apart by being there to take over as the main breeder if one of the pack's parents dies.
Whatever the benefits are of an adoption they have yet to be established. But there are disadvantages too. One is mate stealing. An alpha wolf will have to be vigilant to prevent a stranger from mating with his or her partner.
Advantages Of Pack Living
Ultimately, the unconscious goal of a mated pair of wolves is to survive and reproduce to propagate their genes into future generations (just like humans and other creatures). They do this by raising their cubs to sexual maturity so that their cubs also have the chance of reproducing; after all, it is their parents' genes that they are carrying. Living in a group aids this objective. However, it is likely that there are several immediate reasons for living in a pack and a wolf stays with the pack or leaves it depending on the particular balance of costs and benefits affecting the individual.
The following are some possible reasons why it is advantageous for an individual to live in a group.
Teaming up with several adult wolves makes catching large prey easier and more frequent. Although there is no strong evidence to support this speculation. Even so, packs are larger where prey are more obtainable.
A pregnant wolf is unlikely to raise her cubs successfully without the support of another wolf to bring her food when she is confined to the den nursing her cubs.
Cubs stand a better chance of surviving when more wolves contribute to their care, such as bringing them food and guarding them from danger.
The young adults in a pack have the advantage of a protective environment where they learn the skills of survival before they disperse. Also, if they leave their natal group and then are unable to find a niche for themselves, they might return home to a safe haven to wait until conditions improve when they can try again.
There is the possibility that one or both of a pack's alpha wolves might die, in which case one of their offspring might take possession of their territory. Supplanting a parent could be a good strategy for a wolf. It is less risky than dispersing into a hostile world, especially when there is a glut of wolves in the region and no available space to elbow in a new territory.
A belligerent neighbouring pack might take over your territory by killing off the members of your pack if they greatly outnumber you. So more wolves working as a pack are better able to defend their territory, and therefore their food source, from large neighbouring packs.
However, disadvantages begin to accrue with too many wolves in a pack. Some of these drawbacks have been covered under 'Pack Break Up & Splitting' above. One way or another the time can come when wolves leave their pack to take a chance and strike off alone to make their own way in life. Dispersal and lone wolves are discussed in How Wolves Reproduce.
© Wolf Trust 2004. All rights reserved.
|
Home - Wolf Trust Home - Thinking Wolves |