Obtaining Sustainable Population Structures for the Management of Red Deer

Abstract

Cervus elaphus populations are spreading and growing in many parts of Europe. This growth can have detrimental effects on biodiversity and ecosystem function. Successful strategies to manage large herbivores require reliable information on density and population trends. This paper presents a methodology to achieve a sustainable distribution of red deer by age and sex classes over time. Instead of traditional algebraic methods, the method consists of a simple iterative process that uses convergence to obtain the dominant eigenvalue and eigenvector of the biological matrix from an initial population. This eigenvalue represents the annual growth rate of the population, and the eigenvector represents the ideal age and sex class distribution of the population. The method has been applied to a fenced preserve in the province of Toledo, Spain. An annual population growth rate of 1.63 (dominant eigenvalue of the biological matrix) was obtained from an initial population and the biological matrix of the deer on the preserve. The convergence of this rate occurred in year 14, but the carrying capacity allows for a population close to the population in year 17 according to the prediction, which is therefore considered to be the year when the ideal population distribution is achieved. This methodology allows managers to numerically justify how to control population growth to preserve biodiversity and sustainability.