Social Structure - Family TiesR., Dave.  "Coyotes in February - Yellowstone National Park" (image). <http://www.flickr.com/photos/sigmaeye/398322964/> Accessed 12 April 2009.

Coyotes have an important social structure, much like that of wolves, that relies on strong family bonds and shared territories.  These packs have an alpha pair and three to eight additional family members.  The size of the pack usually depends on the availability of food and the amount of territory available.  The alpha pair are usually the only ones to mate unless the population is threatened, as occurs sometimes with overhunting.  Even so, it is very rare for a second female in a single pack to have pups.
Pépin, E. “Pack of Coyotes”. (image). <http://www.flickr.com/photos/zorro-the-cat/2341951506/>. Accessed 12 April 2009.There are two or more beta coyotes who are responsible for defending territory and helping to look after the pups and the mother.  These betas are siblings from a previous litter that remain with the alpha pair after they are eight months old rather than leaving.  Some pups disperse and meet up with other dispersed animals to form new mating pairs and packs.  This rearrangement of the pack occurs in late fall, when it is decided which of that year’s pups will become nomadic, which will remain as members of the pack, and which will leave to potentially begin packs of their own in an adjacent territory.

Dallaire, J. G. “Coyote_0508”. (image). <http://www.flickr.com/photos/13101875@N00/392648170/>. Accessed 12 April 2009.
The territory occupied by a pack varies in size depending on population density and availability of food.  It can be as large as forty square miles, but most coyote territories are only about one twelfth the size of a wolf pack territory.  Home ranges for rogue mating pairs and nomads are much larger, as they need to avoid established pack territories.  As with most canines, scent marking is used to mark territorial borders.  Often higher objects such as rocks or bushes are marked so that scent is still apparent during winter months when the snow covers the ground.  Coyotes tend to avoid wandering into the territories of other packs, especially during mating season and right after pups are born when the pack is the most territorial and defensive.  In more urban environments there is little pack structure, and mating pairs are often the largest group that is seen.