IMMUNOCONTRACEPTION AS A POTENTIAL CONTROL METHOD OF WILD RODENT POPULATIONS

Rodents have the capacity to periodically reach very high numbers in a gricultural landscapes, reducing agricultural production, and causing considerable environmental and social problems for farmers and their f amilies. Such rodent problems occur worldwide and have a long history. Currently mortality enhancing agents (mainly poisons) are the princip al method of rodent control. This approach raises environmental, ethic al and humane issues, and ignores the inherent high capacity for incre ase in these species. We argue that it is more appropriate to reduce r eproduction than increase mortality. This paper uses house mice in Aus tralia as a case study to explore fertility reduc tion as a potential alternative to conventional methods of control. In particular, the que stion of what level of fertility control is required to have a signifi cant effect on population growth is discussed. A computer simulation, based on the life-history strategies of house mice, examined the effec t of different levels of fertility control on mouse population dynamic s. This simulation provides a reference for future studies of confined populations of mice used to test the effects of fertility control, re fines the design of these experiments and identifies the type of data needed to be collected. Immunocontraception, the process of inducing t he body's immune system to attack its own reproductive cells, is sugge sted as a method for reducing fertility in rodent populations. The adv antages and disadvantages of immunocontraception over mortality-enhanc ing agents are discussed, as are the potential impacts of social struc ture on the efficacy of immunocontraception and the possible applicati on of this control method to other rodent pest situations, particularl y rodent pest problems in Africa.