Wolves are a difficult species to monitor. They are inconspicuous and live at low density in a structured population of territorial packs (Mech and Boitani 2003). In Alaska, wolves live at particularly low densities, and in many areas, human access is limited to air travel. If wolf pack territories were regular and predictable, wolf surveys would be much easier, but it is seldom possible to predict the arrangement of pack territories from studying the terrain. Wolf pack territories overlap one another and change over time. Effective monitoring needs to address not only wolf numbers but the spatial structure of the population. Radio tracking of wolves in Denali has revealed that the park’s wolf population is made
up of a shifting mosaic of pack territories. As packs die out and are replaced by new packs, territory boundaries and patterns of
habitat use change.