Why do A mur tigers maintain exclusive home ranges? Relating ungulate seasonal movements to tiger spatial organization in the R ussian F ar E ast

Wild, solitary felids demonstrate a variety of spacing patterns, with diversity in spatial organization largely attributed to variations in abundance and distribution of important resources, particularly prey. We examined the relationship between territoriality of female A mur tigers P anthera tigris altaica and seasonal movements of a key prey species, M anchurian red deer C ervus canadensis xanthopygus , in the R ussian F ar E ast. We predicted that despite considerable seasonal fluctuations in productivity, red deer density does not change seasonally within tigress home ranges. We analyzed radio‐telemetry data to identify directional movements of deer as an indicator of relative changes in seasonal red deer abundance and distribution, and we looked for seasonal shifts in home ranges of tigresses that could signify tracking of migratory prey. We failed to detect either seasonal shifts in tigress home ranges or significant differences in seasonal prey abundance. Most red deer were sedentary, while those that migrated demonstrated varying directionality of movements. Relatively low average snow depth likely reduced directional migratory tendencies in prey populations. Despite existing theory that might predict high overlap of A mur tiger home ranges, our results suggest that exclusive spacing patterns in this tiger subspecies are at least partly explained by the absence of major spatial and temporal changes in ungulate abundance and distribution. We submit that the assumption that home‐range overlap should increase with increasing home‐range size may require further evaluation in cases such as that of A mur tigers.