The Population Dynamics and Conservation of Primate Populations

Abstract

Primates are among the most threatened taxa, with more than half of all species in jeopardy. In this paper we develop population models to use the kind of data on wild primates that primatologists actually collect. Our survey of recent primate journals suggests that the average field study uses 1.5 years of data from 50 animals. The models are based on the simple Leslie-Lefkovitch matrix. They suggest a simple method that allows assessment, from a few years'' data, of whether a population is collapsing and requires intervention. To a good approximation, populations will collapse when adult survival, per inter-birth interval, is less than 70 percent. Modifications of the basis model incorporate more realistic assumuptions about social organization and density-dependent resource limitation. These allow us to identify population densities at which potential Allee effects operate, and permit more precise estimates of the minimum population sizes and compositions required for successful reintroductions to the wild. The most important result is that populations of primates that live in small family groups may be more prone to "demographic" extinction than are more promiscuous species that live in more extended groups.