Elephant Studies
Population Studies | Genetic Markers | Satellite Tracking
The Gamba Complex is divided into three administrative zones relative to protection of biodiversity—Loango National Park, Moukalaba-Doudou National Park, and an important industrial corridor that lies between and divides the parks. The new government regulation that created the national parks does not clarify the status of the corridor. It is thus assumed that it remains as a Domain de Chasse (a type of protected area not considered in the International Union for the Conservation of Nature, IUCN, categorization).
The Smithsonian/Shell partnership has documented a high biodiversity value in the corridor between the Parks and has demonstrated that the three sections of the Complex serve as an integrated ecosystem. To pursue the corridor's long-term protection, it is important to determine the extent of connectivity between the industrial corridor and the Loango and Moukalaba-Doudou National Parks in relation to human induced impacts on the landscape, allowing for informed decision-making in regard to the long-term management plans of the Gamba Complex.
Large mammals, such as elephants, are excellent indicators of the value of a region as a bridge for population movements because of their landscape level resource needs which lead them to move long distances in search of food and water. When corridors are disrupted, parks become isolated and open populations become closed, resulting in population declines that may lead to local extinctions. Corridors are important as ecological connectors and for migration routes for African elephants.
The Smithsonian Institution is collaborating with the Wildlife Conservation Society on several aspects of elephant research. A three-part study is underway to determine the degree of connectivity of the corridor.
To understand the use of the industrial corridor by elephants, the population size needs to be estimated using standard indirect observation methods as recommended by the African Elephant Specialist Group and the IUCN. Population estimates are based on systematic dung count surveys following patch-occupancy models. Scientists are estimating the proportion of sites used by elephants at six locations in the industrial corridor and the probability of detection of elephants in both the dry and wet seasons. Habitat type and type of and distance to human activity are included as covariates in the model to better understand the observed distribution of elephants. Sampling is being conducted during the dry season and repeated during the wet season to estimate seasonal changes in landscape use. The outcome will be greater understanding of movement patterns and habitat usage by elephants throughout the corridor on a seasonal basis.
Genetic Markers to Estimate Elephant Populations
Smithsonian researchers are pioneers in using genetic markers for estimating wild populations of endangered species. Individual elephants have been identified in Ghana from small samples of dung, providing valuable information on sex ratio, relationships among herds and individual movements. All of these are of great value for conservation planning and management. These techniques are now being applied in the corridor in the Gamba Complex. A study using fecal DNA genotyping and mark-recapture analysis will be used to characterize the elephants in the corridor. By examining the individuals present in the population during the wet and dry seasons, we can determine whether this is likely to be a resident or transient population. Our analysis is also determining whether this region is frequented by female groups with young or primarily by males, either singly or in small bachelor herds. An estimate of the population size using mark-recapture methods will be established.
Satellite-tracking of Elephant Movements in the Gamba Complex
Traversing dense African rainforests following elephants that sometimes travel vast distances at night now can be done by using a satellite-tracking device that contains a Global Positioning System (GPS)—a satellite-based navigation instrument that can determine the exact geographic position by communicating with orbital satellites. The GPS records its position four to six times a day and an attached transmitter sends the location information via satellite.
Smithsonian researchers have successfully applied this technology in tracking Asian elephants in Myanmar. Wild elephants are tranquilized and captured using a dart gun. A specially designed collar is used to attach the tracking unit to the elephant's neck. After the antidote is administered the released elephant returns to its herd. Six elephants are collared in the corridor. The information gathered from this study will allow us to track these animals throughout the year and learn about the habitats they frequent, the resources they seek, the paths they travel and the value of the corridor in their life.
