Modelling management decisions to prevent extinction Population and conservation biologists rely heavily on mathematical tools. Scientists have developed new models to link species life-history to changes in traits, including effects of management interventions. Health © Thinkstock Matrix projection models enable the evaluation of management decisions geared towards avoiding extinction and, despite their complexity, are easily implemented with standard matrix software. Integral projection models (IPMs) replace the discrete representations of classes (age, height, weight, etc.) in matrix projection models. IPMs provide a continuous structure that could potentially avoid artifacts due to arbitrary class distinctions. The EU-funded project 'A test of Bayesian decision analysis and the implications for conservation' (RHINOMITE) originally intended to study Bayesian population models. Later, team members turned to IPMs to link species life-history to traits such as body size. The team focused on ungulates — hoofed mammals that walk on their toes, and includes animals such as the rhinoceros, zebra and warthog. Scientists’ investigated global ungulate species’ diversity and drivers of local extinction. They then developed an IPM to evaluate management intervention effects on ungulate species weighing up to 500 kg. The model allows scientists working on species with limited data to test the effects of interventions. Intervention measures include hunting and translocation of population demographics such as population growth rate, female reproduction as well as traits like body size. The team also collaborated with other researchers to develop a two-sex IPM for bighorn sheep (Ovis Canadensis) using a 40-year individual-based datasets. It provided insight into effects such as shifts in population body size due to trophy hunting. RHINOMITE outcomes are in various stages of publication. The IPMs provide insight into both demography and evolution by linking changes in life history to changes in certain traits. Conservation biologists now have a very powerful tool to aid in their fight against species extinction.
