This rite is required to open any sort of moot. At such moots, the caerns of the Garou are recharged with Gnosis. The rite always includes a prolonged howl led by a Garou known as the Master of the Howl. The howl varies by tribe and sept, but always expresses the unique nature of the sept. All Garou involved must form a circle within the caern itself before they commence howling. There are numerous variations on the basic requirements - the Red Talons often bite their own paws and scratch their blood into the earth, while the Uktena pass their most powerful fetish from one to another as each in turn adds her voice to the howl - but the howl must always echo forth and the eternal circle form.
The rite must be performed at least once per month to keep a caern consecrated. During the course of a moot, the participants must empower the caern with five Gnosis points per caern level in order to replenish it fully.
Source: Werewolf the Apocalypse