January has seen the commencement of a five-month forest elephant survey in the Ebo Forest, Cameroon, by the San Diego Zoo’s Central Africa Regional Program, funded by the U.S. Fish and Wildlife Service’s African Elephant Conservation Fund.

The project aims to assess the distribution and relative abundance of forest elephants throughout the Ebo Forest and the areas currently outside the proposed Ebo National Park, an area occupying a 1,500 square-kilometer footprint, but made considerably more when the inclines of the steep mountain chains are taken into account.

Forest elephants are very special creatures and are now considered a different species from their savanna counterparts. They are much smaller in size, which helps them move through the densely forested habitat, have smaller, more rounded ears, and we believe they move through the forest in smaller groups than savanna elephants, looking for fruits, which form an important part of their diet.

Finding forest elephants in a forest is surprisingly difficult. The limits to visibility in the habitat, and their seeming ability to melt into the background do not help matters, and when startled they either run away, or charge, neither of which is helpful when conducting surveys. So the best way to estimate their abundance is by looking for evidence of their presence, and luckily their dung piles remain on the forest floor for several weeks! Statistically rigorous surveys are able to determine densities of elephants from the dung pile’s density without ever seeing an elephant, but when densities of elephants are low, reliable statistics are hard to produce. Our surveys will not determine absolute densities of elephants because we are not yet certain if there are sufficient elephants in the Ebo Forest to produce an accurate estimate in this way, so we are first conducting abundance surveys.

We have established a series of “virtual” parallel paths based on compass bearings that will cover the whole forest at systematic intervals, totaling around 350 kilometers in length as the crow flies. Walking along a predetermined routes is not as easy as it sounds, as my next blog will detail: obstructions such as enormous boulders, rock faces, enormous snakes, and fast-flowing rivers have to be avoided, which can add unwanted complication into the analyses of the dung pile abundance. Also, when the team of researchers travels along the predefined routes, it is important that as little disturbance of the natural forest is made as possible, but this is incredibly hard to achieve when fighting your way through a tree fall area where lianas, vines, and shrubs spring up with vigor to take advantage of the light. So we have to move in single file using secateurs, and when conditions are extreme we use a machete to carefully cut a path through the vegetation.

Studying dung piles has other interesting uses beyond providing the ability to survey elephant distribution and abundance: it also allows us to understand the diet of the elephants in detail by examining the seeds in the dung and looking for other components such as bark, leaves, and occasionally grasses.

Additionally, it is possible to extract the elephant’s DNA from dung, which means genetic analysis could also be performed, although this is not a goal of the current project.

Shortly I will post the progress of our work on the elephant survey in January, together with a few photographs of some of the surprises along the way. The survey will continue until May, when we will analyze results to determine the status of the elephant populations in the Ebo Forest.

Dr. Bethan Morgan is a Central Africa Program specialist with the San Diego Zoo.
Read her previous blog, Gorillas: Taiping Four.

Posted in Conservation, Default, Field Studies, General | Link to this post

You can follow any responses to this entry through the RSS 2.0 feed. Scroll to the end to leave a comment. Pinging is not allowed.