The demographic consequences of releasing a population of red deer from culling

A change in population density can generate spatial and demographic effects that can have an impact on fluctuations in population Size for many years. Although the demographic effects of time lags have been incorporated into analyses of time series data, there are few detailed descriptions of the long-term demographic consequences of a change in density. We use detailed, individual-based data from a population of red deer (Cervus elaphus) from the North Block of the Isle of Rum, Scotland, to describe long-term demographic and spatial effects of a change in density. The population was released from hunting pressure in 1972. Over the following 10 years population density doubled and, since the early 1980s, has fluctuated around ecological carrying capacity. The cessation of culling led to long-term transient spatial and demographic effects that have persisted for 30 years. Different vital rates responded to the increase in density at different rates, causing long-term changes to the demographic and spatial structure of the population. These changes altered the impact of different age- and sex-specific vital rates on annual changes in population size. These changes are still ongoing, 30 years after cessation of the cull, suggesting that a change in density may generate transient dynamics that persist for several generations.