to public health highlights the importance of maintaining and perpetuating the chimpanzee resource in order to address critical needs in biomedical research. While the present population is sufficient to meet projected research needs over the next five years, if the resource is to be maintained in perpetuity a chimpanzee breeding program will have to be implemented in the future and will result in resumed growth of the population.
Continued breeding of chimpanzees to meet future research needs will necessarily result in further production of surplus animals (i.e., animals not needed for breeding or research programs) because of the practical inability to exactly match sex-specific production and death rates. Demographic and genetic management schemes based on projected demand should be used to minimize the size of the surplus population. However, research demand for chimpanzees is difficult to project accurately and management programs cannot be expected to completely prevent a surplus. Effective mechanisms for dealing with the current surplus animals, and the new surplus animals that will be generated if breeding for biomedical research is continued, are required.
Chimpanzees are expensive animal models, with direct cost per diem rates ranging between $15 (representing a breeding and maintenance facility with no requirements for extensive biohazard containment facilities or intensive research manipulations) and $30 (representing a facility with an active research program involving biohazardous agents). Dyke et al. (1996) have determined that the lifetime costs projected to be incurred for a single animal born in 1995 range between $113,430 and $226,860 for males depending upon the per diem rate, and between $160,860 and $321,710 for females because of their longer average life-span (Dyke et al., 1995).
These high costs apply to all chimpanzees maintained in a colony, including breeders, research animals, and surplus animals that have no potential utility for breeding or research. An alternative perspective on the costs of research with chimpanzees is given by evaluating all the colony costs that go into the production of each individual research chimpanzee. For example, the total cost of producing a naive research chimpanzee includes the costs both of maintaining that animal and of maintaining the breeders to produce the animal. This suggests that the