Pack is a social group of conspecific canids. Not all species of canids - notably the red fox - form packs. Pack size and social behaviour within packs varies across species.
African wild dogs (Lycaon pictus) live and hunt in packs. Males assist in raising the pups, and remain with their pack for life, while the females leave their birth pack at about age two and a half years old to join a pack with no females. Males outnumber the females in a pack, and usually only one female breeds, with all of the males. African wild dogs are not territorial, and they hunt cooperatively in their packs, running down large game and tearing it apart. They cooperate in caring for wounded and sick pack members as well as the young.[1]
Gray wolves (Canis lupus) usually live in packs which consist of the adult parents and their offspring of perhaps the last 2 or 3 years. The adult parents are usually unrelated and other unrelated wolves may sometimes join the pack.[2]
Black-backed jackals (Canis mesomelas) have a single long term mate, and usually hunt singly or in pairs. Both parents care for the young, and the parents and their current offspring are the pack. They will cooperate in larger packs to hunt large game.[3]
The Ethiopian wolf (Canis simensis) has different social behavior from the gray wolf: pack members hunt alone for rodents, and come together mainly to defend their territory from other packs.[4]
Domestic dogs (Canis lupus): Despite being genetically the same species as the grey wolf, it is unclear what the similarities are between the pack behaviour of the dog and the gray wolf. Domesticated dogs have had humans as part of dog social structure for at least 12,000 years, and human behaviour is not the same as wolf behaviour. Studies of dog behaviour include studies of dogs and their interactions with humans,[5] and "dumped" or "road" dogs that were raised by humans and then left to fend for themselves (e.g. The Tuscany Dog Project).[6]
Gray wolves (Canis lupus) have been shown through genetic analysis to be of the same species as the domestic dog. Although 12,000 (or more) years of domestication have altered the dog physically and socially, dog trainers have attempted to use the close genetic relationship between the dog and the gray wolf to develop techniques for modifying domestic dog behaviour (based on research on gray wolves in the wild.)
One of the most persistent theories in dog training literature is the idea of the "alpha wolf," an individual gray wolf who uses physical force to enforce dominance hierarchy within the wolf pack. The idea was first found in early wolf research, and later adopted by dog trainers.[7] The term "alpha" was popularized in 1976 in the dog training book "How To Be Your Dog's Best Friend" (Monks of New Skete), which introduced the idea of the "alpha roll", a technique for punishing unwanted dog behaviours. Human psychologist and dog trainer Stanley Coren in the 2001 book "How to Speak Dog" says "you are the Alpha dog...You must communicate that you are the pack leader and dominant".[8]
The idea of an aggressively dominant "alpha wolf" in gray wolf packs has been discredited by wolf biologists and researchers, and so-called "alphas" in packs are merely the breeding animals. According to wolf biologist L. David Mech,
"Calling a wolf an alpha is usually no more appropriate than referring to a human parent or a doe deer as an alpha. Any parent is dominant to its young offspring, so "alpha" adds no information. Why not refer to an alpha female as the female parent, the breeding female, the matriarch, or simply the mother? Such a designation emphasizes not the animal's dominant status, which is trivial information, but its role as pack progenitor, which is critical information. The one use we may still want to reserve for "alpha" is in the relatively few large wolf packs comprised of multiple litters. ... In such cases the older breeders are probably dominant to the younger breeders and perhaps can more appropriately be called the alphas. ... The point here is not so much the terminology but what the terminology falsely implies: a rigid, force-based dominance hierarchy."[9]
Training techniques assumed to be wolf pack related such as scruff shaking, the "alpha roll" and recommendations to be "alpha" to your dog continue to be used and recommended in dog training.[10] In addition, the use of such techniques may have more to do with human psychology than with dog behaviour; "Dominance hierarchies and dominance disputes and testing are a fundamental characteristic of all social groups... But perhaps only we humans learn to use punishment primarily to gain for ourselves the reward of being dominant.[11]