DZANGA! CENTRAL AFRICAN REPUBLIC
Much of what we know about forest elephants comes due to the persistence and dedication of Andrea Turkalo at this forest clearing. Her sustained presence at this field site, and her sincere relationship with the local Ba' Aka population, have probably been the most important factors in keeping poaching to a minimum at the Dzanga clearing. We owe an incalculable debt to Andrea and her commitment to forest elephants.
Here's a lovely video clip of the elephants in Dzanga Bai. In addition to occasional elephant rumbles and African Grey Parrots, you can hear Andrea identifying elephant families.
© Andrea Turkalo
Recording units, placed along a 1 kilometer line going into the forest, recorded the progressive reduction in sound intensity. This information has allowed a statistical model to be developed to predict the area over which elephant calls can be detected surrounding a single recording unit. Results from Dzanga suggest that low frequency calls could be detected up to 860 meters corresponding to 2.3 square kilometer area of detection surrounding a recording unit.Developing Methods to Count the Unseen
Forest clearings, like Dzanga, provide the rare opportunity to actually observe forest elephants and their interactions with one another. Although clearings, called 'bais' by Central Africans, are scattered throughout the Congo Basin, forest elephants spend less than 5% of their lives in these openings! Most of the time they are roaming the rainforest in small groups, often just mom and her dependent offspring, looking for fruits and succulent browse, or traveling between resources such as bais. Scientists also know very little about what proportion of a local population of elephants actually visit the forest clearings.
Developing a method to count animals, to estimate populations, in habitats where they are not easily seen has been a driving force behind the research of the Elephant Listening Project. Taking advantage of the visibility and high density of elephants at Dzanga, Mya Thompson and co-workers quantified the relationship between number of calls and number of elephants (below).