Lemur disease ecology: Linking health, ecosystem viability, and conservation in Madagascar

Background/Question/Methods

Anthropogenic effects on ecosystems have reached unprecedented levels, with potentially disastrous consequences for global environmental, wildlife and human health. Human encroachment into wildlife habitat leads to degradation and fragmentation, which in turn increases contact among wildlife, humans and domestic animals. Global concern has grown over the risk of emerging infectious diseases from zoonotic origins due to this increasing rate of contact. With Madagascar’s rampant rate of human population growth and deforestation, its incredible species diversity, the widespread presence of domestic and invasive species, and its evolutionary isolation, it can be viewed as a “perfect storm” of potential disease emergence. A number of diseases typically associated with human and domestic animals have already been documented in lemur populations, including toxoplasmosis, human herpesvirus and West Nile Virus, indicating the potential for further disease transmission. Consistent baseline health monitoring of lemur populations provides an effective tool for evaluating wildlife health and preparing for future disease occurrences. Limited, disconnected surveys of lemur health have been conducted, yet there remains a need for more extensive, country-wide evaluations that also assess diseases of invasive species, domestic animals and humans. Our study investigates how spatial, climatic, anthropogenic and conservation factors affect the occurrence of infection on an island-wide scale in Madagascar. We incorporated lemur health data from 13 reserves throughout the island with habitat characteristics and evaluations of human pressures affecting each site.

Results/Conclusions

In preliminary data, lemurs in smaller reserves that lie within 5 kilometers of human settlements suffer higher parasite prevalence, richness, frequency of multiple infections, and reduced body condition. By utilizing statistical and geospatial tools, we assessed the characteristics of sites that exhibited the highest infection rates; these data will assist in predicting potential problem areas in the future. In Madagascar, human development around protected areas directly affects wildlife health by increasing exposure and decreasing habitat quality. By studying the interactions of spatial patterns, habitat quality and anthropogenic pressures, we can more accurately assess the health of lemur populations in Madagascar and provide valuable information for reserve design. These data can also inform public health, conservation, economic and social policy strategies to address disease risk within a multidisciplinary framework.