Written by Erica Metelovski and Dr. Virginia Landau with
Dr. Randy Fulk of the North Carolina Zoological Park

Increased knowledge and care standards have also lengthened the life span of our closest living relative- the chimpanzee. Members of an endangered species, chimpanzees in captivity are protected as part of a global conservation effort. Modern zoos focus on health care for the individual chimpanzee. Their success as caregivers has resulted in a greater longevity for zoo chimpanzees and a growing number of senior chimpanzees. Zoo chimpanzees are also protected as individuals who contribute genetic material to a small but still viable group of approximately 300 chimpanzees.

It is with this in mind, that we have undertaken an holistic study of older chimpanzees. For it is only through understanding their social, psychological and biological needs that we will be fully able to supply the most adequate care for senior chimpanzees in zoos.

The most recent edition of the Species Survival Program (SSP) Studbook for captive chimpanzees, published in 1994 and updated in 1997, lists 42 chimpanzees 34 years of age and older, living in American Zoological Association accredited zoos and Taronga Zoo, in Australia. The age of 33 was estimated as the beginning of old age for chimpanzees living in the wild. based on this statistic we have designated old age for zoo chimpanzees as beginning at 34.

Further research is needed to establish the accuracy of this figure. The oldest chimpanzee in zoos, according to the studbook, is 59-year-old (+ or - 3 years) Little Mama, living at Lion County Safari, in Florida (+ or - 3 years attributed to past inaccurate estimates of wild caught chimpanzee infants). Inky, the next oldest zoo chimpanzee is 54 years and also lives at Lion County Safari. Forty chimpanzees range between 54 and 34. Of these 28 are females and 12 are males. Thirty-four of the geriatric chimpanzees were captured in the wild as infants. Five of the remaining 42 are classified as origins unknown. Only three were documented as being born in zoos.

Founder chimpanzees are those individuals who contribute "new and unrelated genes" to the population. Thus chimpanzees captured in the wild, or those known to not have any relatives in captivity, became the basis for the e founder chimpanzee population. Thus chimpanzees captured in the wild, or those known to not have any relatives in captivity, became the basis for the founder chimpanzee population. As protection laws have prohibited any further capture of chimpanzees for transport to United States zoos, these chimpanzees represent the last of the wild born chimpanzees in captivity. This select group of individuals offers a unique opportunity for us to learn about their lifestyle and needs.

Though their pasts of these chimpanzees are not always clearly documented, many spent their early years as pets or circus stars. While some have been frequently transferred, others have remained at the same zoo for up to thirty years. Whether or not this environmental upheaval or stability has affected the chimpanzees is yet another issue which invites exploration. Still other geriatric chimpanzees spent their early years as research subjects in laboratories.

Aging humans and chimpanzees must contend with a number of problems, some of which are inevitable. Chimpanzees, like humans, suffer from physical characteristics of aging that alter the appearance of the individual, thinning or graying of hair, diminishing muscle tone, and vision and hearing deficits. Other biological signs of aging, such as cataracts, missing teeth, and arthritis which impact the quality of life, can impede an individual's ability to care for him or herself.

Zookeepers monitor the health as well as the social behavior of chimpanzees. As their principal care givers, they have come to know them intimately. They frequently report that older chimpanzees seem to "slow down" as they grow older. However few, if any, of these chimpanzees currently receive special housing or diet. Most continue to occupy the same social ranking positions as those of their youth. Maternal skills seem to be also unaffected.

The impact of age on intellectual and physiological capacity also deserves attention. In line with human research, curiosity as to the patterns of personality change or stability with age is but one of the many areas that merits investigation. Inquiry into whether certain aspects of intellect tend to decline, improve, or remain stationary offers a viable option for longitudinal study.

The availability of this unique population of senior chimpanzees creates the opportunity to focus on learning about the founder chimpanzees. At the 1997 ChimpanZoo conference in Little Rock, Arkansas, we hope to learn more about and share information regarding the special requirements of senior chimpanzees. By doing so, we not only fulfill our inherited obligation to guarantee senior chimpanzees much deserved quality care, but may succeed in unlocking some mysteries regarding their longevity.

Hayflick, Leonard. How and why We Age. New York:Ballantine Books, 1996