Pack structure

Quileute shape-shifter packs are organized on a system of rank similar to what is found on real life wolves.

Alpha
"No one could refuse the Alpha."

- Jacob Black

The Alpha is the highest ranking member of a wolf pack and its leader.

Responsibilities
As the leader, the Alpha holds absolute control over the pack, allowing the whole pack to act as a single unit in fights, emergencies and when otherwise needful, eliminating any delay between an order and its execution.

After he rises to Alpha status, Jacob mentions feeling paternal towards the other wolves in his pack, as if he should put himself between them and an eventual danger that should appear.

The Alpha wolf can choose his most trusted companions to become his second, also known as Beta, and third. Both are then subsequently given the responsibility to lead the packs if the Alpha is unable to. The chosen mid-level leaders can also select their own second and third to assist them, allowing a finely tuned organization of the pack.

Powers
The Alpha is no different from other wolves with respect of slowed-down aging while phasing, rapid healing, enhanced senses, telepathy, and physical strength. Same as them, he's sensible to vampire venom, which is fatal to shape-shifters.

Telepathy
In addition to the regular telepathic link with other werewolves, Alphas can share they thoughts with Alphas from other packs, though in this case communication is far from indiscriminate. They can willingly choose to share a thought, even from a distance, and can willingly close themselves off, something they can't do with their pack mates. In addition, should the Alpha's mind become mentally protected from harm, the other wolves' will also be protected. This was proven when Bella Swan shielded Sam and Jacob with her power, providing protection to the entire packs. This may also mean that if the Alpha falls victim to a psychically supernatural power, the rest of the pack is also subject to it.

Alpha voice
"... The compulsion to follow orders felt like puppet strings hooked into all of my muscles. One foot forward, now another."

- Jacob's description of being controlled by an Alpha's command.

The Alpha voice is an ability that only a genetic or elected Alpha Shape-shifter possesses. It is unknown how the alpha voice works and whether an alpha shape-shifter can ues his alpha voice to command his pack members in both human and wolf forms. Once an alpha shape-shifter gives orders to members of his pack, his orders are obeyed blindly. The pack members cannot directly disobey commands even if they are in disagreement. This ability, however, is limited to pack member and cannot influence another Alpha shape-shifter.

The beta is also able to use this ability, however, not on an alpha. The beta may give orders to other pack members in this way, overruled only by the alpha, if need be.

Candidates
If the Alpha candidate has no interest in the role, he can, on approval of the rest of the pack, pass it to another wolf (generally the first phased among the possible choices). A genetically determined Alpha has a stronger voice than a chosen one.

History
In the original La Push pack, Ephraim Black was the Alpha. Sam Uley became the next one, since he was the first to phase. Jacob Black was offered the leadership when he also phased, but refused. Jacob later became the Alpha of his own pack after an argument between him and Sam. Traditionally, the Alpha of the pack is the leader of the entire Quileute tribe.

The position of Alpha could also apparently be fought over, but it seems the lineage of the wolf has more to do with it. When Jacob took his rightful place as Alpha to keep Sam from attacking the Cullens, Sam thought that he meant to usurp him.

Jacob explains his fight for wolf claim as "My body was responding to the challenge. The primitive core of my wolf sense tensed for battle of supremacy."

Known Alphas

 * Taha Aki
 * Taha Wi
 * Ephraim Black
 * Jacob Black
 * Sam Uley

Beta
Beta is the term Bella Swan unofficially gave to the second-in-command of a shape-shifter's wolf pack.

In Eclipse, Jacob laughs at this, after explaining to Bella about the Alpha's role. The "Beta" is able to give orders to other pack members, overruled only by the Alpha, if need be. To become promoted, the chosen wolf must be trusted by the Alpha. How the chain of command extends to lower ranking members is unknown, but it may be surmised that it is similar to what is found in wolves. When running in formation, the Beta runs on the Alpha's right shoulder. He can also choose another wolf to rule under him if something happens to him.

The Beta can also give command to his most trusted wolf should anything happen to him and the Alpha.

Known Betas

 * Levi Uley (Ephraim Black's pack)
 * Jacob Black (Uley pack, left to start his own pack)
 * Seth Clearwater (Black pack before his sister joined)
 * Leah Clearwater (Black pack)
 * Jared Cameron (Uley pack after Jacob left)

Third
A third is referred to the third-in-command of a shape-shifter's wolf pack. He is supposedly next in line to act as Alpha if the original Alpha and his Beta are incapacitated.

The "third" is able to give orders to other pack members, overruled only by the Alpha and his second, if need be. To become promoted, the chosen wolf must be trusted by the Alpha. How the chain of command extends to lower ranking members is unknown, but it may be surmised that it is similar to what is found in wolves. When running in formation, the third runs on the Alpha's left shoulder. He can also choose another wolf to rule under him if something happens to him.

The third can also give command to his most trusted wolf should anything happen to him and the Beta and the Alpha.

Known Thirds

 * Quil Ateara II (Ephraim Black's pack)
 * Paul Lahote (Uley pack)
 * Embry Call (Black pack) in the novel only
 * Seth Clearwater (Black pack) in the movie only