Management of the Collection for Research
The goal of the program is to supply the best research and educational Lemur catta population possible within the bounds of excellent care of the animals. To that end, the four troops emulate healthy wild populations in ranging, troop interaction, foraging, and social processes. In addition, these troops supply research opportunities often not available in the wild, since the genealogies of the animals are known, animals are readily identifiable, and some limited tissue specimens are available in conjunction with annual physical examinations. Invasive research is not supported. In addition, it is the goal of the program to maximally support researchers through small grants, free housing, and on-site support including vehicles. Educational use of the collection, particularly to train beginning primatologists, is encouraged.
Not all of these goals have been met at this time. Currently there are 51 L. catta on the island in four free-ranging troops, each of its own matriline. The home ranges of the troops are too far apart at this time to readily support studies of troop interaction, but that is being changed by moving feeding stations and planting forage between the troops. The current age distribution within the troops is skewed toward younger animals and fewer adult males, but that will correct itself in the next two years through breeding.
Natural feeding behavior is emulated through scattered groups of feeding stands throughout the home ranges of the troops. Fruiting trees are being planted at the same sites, with emphasis on native plants to avoid the high sugar content of domestic fruit. The lemurs are supported with Mazuri primate biscuits and small amounts of fruit, which is limited to encourage foraging. The lemurs forage heavily on grape leaves and palm berries, and to a smaller degree on a wide variety of native plants. One staple in their forage (new growth red bay leaves) has been largely destroyed on the island by an exotic beetle infestation.
Ranging behavior is being encouraged through the placement of feeding platforms. The new fourth troop is being released between the existing troops to increase density and inter-troop contact.
New males will be introduced to troops by supporting them in peripheral locations, so that they can work their way into the troop social structure. Males that leave their natal troops are given the opportunity to join other troops. Rejected females will be used to start new troops until the colony reaches the maximum population sustainable by the resources of the foundation.
All animals are captured for an extensive physical examination and preventive treatment for warble flies each June. Blood and DNA samples are taken at that time. Each troop is captured as a group, so that dominance hierarchies are not disrupted by the absence of an animal. Veterinary treatment for injuries and illnesses is designed to minimize troop disruption, including where possible limiting removing an animal to less than a day. When critical care requires that an animal be away long enough for it to lose status, it may be considered as having “died,” and be released as a member of a new pair at a new site.
All animals have access to shelter at all times. On days before foul weather is predicted the animals are fed near their release cages. Fortunately, potentially dangerous temperatures occur when natural forage is least available on the island. If weather that might pose a risk to the animals is predicted, they are confined to heated shelters. This can be expected to happen several times in any winter. Animals are released again as soon as weather permits, usually within a day or two.
If particular aspects of management of the collection would be important to your research, do share your thoughts with the Director. This colony exists only to support research, so we will be sensitive to your needs. Managing lemurs to emulate healthy natural troops on this island has its own challenges. When the program staff has gained more expertise in this area, it may be willing to consider additional species for release. Any species released would have to meet the criteria of being of interest to active researchers, being available for release, and being suited to the habitats found on the island.