Multiple ecological pathways to extinction in marine and terrestrial mammals

Background/Question/Methods

As human population and resource demands continue to grow, biodiversity conservation has never been more critical. About one-quarter of all mammals are in danger of extinction, and over half of all mammal populations are in decline. A major priority for conservation science is to understand the ecological traits that predict extinction risk, and the interactions among those predictors that make certain species more vulnerable than others. Here, using a new database of nearly 4,500 mammal species, we use decision tree and random forest models to quantify the multiple interacting factors that predict extinction risk.

Results/Conclusions

We show that the correlates of extinction risk vary widely across mammals, and that there are unique pathways to extinction for species with different lifestyles and combinations of traits. We find that risk is relative, and that all kinds of mammals, across all body sizes, can be at risk depending on their specific ecologies. Our results increase understanding of extinction processes, generate simple rules of thumb that identify species at greatest risk, and highlight the potential of decision tree and random forest analyses to inform conservation efforts.