Cayo Santiago

Cayo Santiago Today

Cayo Santiago is a 15.2 ha (38 acre) tropical island located 1 km off the southeastern coast of Puerto Rico. All of the rhesus monkeys on Cayo Santiago are free-ranging and maintained under semi-natural conditions. The population is composed of approximately 950 monkeys living in naturally formed social groups. All monkeys on Cayo Santiago are direct descendants of the original 409 monkeys who were imported from India, and released in the island in 1938.

Monkeys of Cayo Santiago are known on an individual basis. Daily census and monthly reports incorporate demographic changes in the population. This information is stored in our computerized database. Investigators conducting research receive a monthly census report. Our database provides information on dates of birth and death, sex, maternal lineage, female parity, and immigrations/emigrations for Cayo Santiago population.

Cayo Santiago has three 1/4 acres corrals that are used for daily provisioning (Tekland, NIB Primate Diet Modified: crude protein not less that 20%; crude fat not less than 5.0%; crude fiber not less than 10.0%). The animals also forage on the natural vegetation and routinely consume soil. Water is provided ad libitum through water spouts.

Cayo Santiago is off the coastal village of Punta Santiago in the municipality of Humacao. Punta Santiago is approximately an hour and a half drive from the airport, and Sabana Seca, and forty-five minutes from the Medical Sciences Campus. The Caribbean Primate Research Center facility at Punta Santiago provides working space for the Resident Scientist, Colony Manager, Secretary, Chief Census Taker, Assistant Census Takers, visiting scientists and students. The office is equipped with telephones, computers, Ethernet connections (bring your own card), a fax machine, and a photocopy machine.

A second building provides a Revco -85° C ultra low freezer, laboratory space, warehouse space, a shower for employees, and a feed storage room. A veterinary clinic on the island of Cayo Santiago, enables investigators to conduct various on site biomedical research projects.

Monkeys on Cayo Santiago are captured, exclusively during the annual roundups (app. Mid January to mid March) in the feeding corrals. The priority of this annual trapping season is to tattoo animals, ear notch individuals for identification, inoculate for tetanus, and bleed monkeys for paternal and maternal DNA fingerprinting. Biosamples and morphological samples can be collected during this period for approved protocols. Each year monkeys are culled from the island for population control and to maintain an adult sex ratio of one male per two females. Culling decisions are based on several criteria with an emphasis on preserving genetic variation and naturalistic group composition.

Through a competitive grant application at the National level, Cayo Santiago received an award from the National Center for Research Resources (NCRR) of the National Institutes of Health.