A comprehensive transition matrix model for projecting production and resource consumption in reindeer herds

Abstract

A deterministic herd model was developed for projecting the dynamic changes in reindeer herd size and structure under defined harvest policies. The model distinguishes between females, males and castrates up to an optional number of age-classes. Calves are further classified based on the age and status (present/absent) of their mother. The yearly cycle is divided up into a maximum of 11 time steps, including five grazing seasons. The model is described in general terms using the Leslie matrix approach in order to suit different computer implementations. The conventional Leslie matrix solution was extended so that nonlinear features and stochastic variation in performance parameters could be considered. Computational procedures for making detailed economic evaluations of harvest output and herd feed requirements or consumption are given. This general purpose model can be tailored to specific study conditions. An advantage of this is that the sensitivity to necessary approximations can be tested with the general purpose model. The model is intended for use in both research and extension work.