Elephant Expedition

We are very happy and excited to announce that the results of Elephant Expedition are now available for public download through this link rdcu.be/bME2p .

Some key findings were:

• Mean forest elephant density at the forest edge is
  higher than in most of the forest interior areas.
• The forest edge is an important food resource for
  forest elephants, especially during the dry season.
• Elephant paths at the forest edge act as firebreaks,
  protecting the interior forest from burning.

A short summary of the research results:

Forest edges that border savanna are dynamic features of tropical landscapes. Although the role of fire in determining edge dynamics has been relatively well explored, the role of mega-herbivores, specifically elephants, has not received as much attention. We investigated the role of forest elephants in shaping forest edges of the forest–savanna mosaic in Lope´ National Park, Gabon.

Using forty camera traps, we collected 1.2 million images between May 2016 and June 2017. These images were classified by over 10,000 volunteers through an online citizen science platform. These data were combined with a 33-year phenology dataset on elephant-favoured fruiting tree species, and field measurements of elephant browsing preferences and damage.

Our results showed a strong relationship between forest elephant density at the forest edge and fruit availability. When fruit availability was high, elephant density at the edge reached values nearly double the highest densities ever reported in any other part of the landscape (7.5 elephants km-2 in this study vs the previous highest estimate of 4 elephants km-2).

The highest elephant densities occurred at the end of the dry season, but even outside of this high density period elephant density at the forest edge (2.4 elephants km-2) was more than double what other studies estimate for forest interiors with low human hunting pressure (1 elephant km-2). We found forest elephants to be selective browsers, but their browsing was non-destructive (in contrast to savanna elephants) and had little effect on tree size demography.

Elephant paths acted as firebreaks during savanna burning, making them inadvertent protectors of the fire-sensitive forest and contributing to the stabilising feedbacks that allow forest and savanna to coexist in tropical landscapes.

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The research team at Elephant Expedition would like to thank you all so much for your help with the project. Honestly, having you be part of the project ended up being one of the parts we enjoyed most! This work wouldn't have been possible without you, thank you thank you thank you!

Anabelle