Photos show how species are returning to reforestation areas in Madagascar

– Despite extensive conservation efforts worldwide, biodiversity loss continues, especially in tropical regions such as Madagascar. We therefore need to develop methods that allow us to monitor biodiversity effectively, so that conservation managers can quickly assess and respond to changes, says Sheila Holmes, researcher at SLU and senior author of the study.

The researchers tested both motion-triggered cameras and acoustic recording devices at five study sites in the eastern rainforest region of Madagascar. Cameras were placed both in the forest canopy and close to the ground to capture as many species as possible. The aim was to evaluate how effective the methods were for surveying seed-dispersing species such as birds and lemurs. These animals play a key role in maintaining biodiversity by eating fruits and dispersing seeds through their droppings.

Effective methods in complex environments

The researchers identified 78 percent of the seed-dispersing species expected to occur at the sites, based on distribution maps and previous reports. They also detected species that had not previously been recorded at those sites.

Monitoring biodiversity requires both time and resources, and many studies rely on a single method.

– Our study shows that multiple methods are needed to get a complete picture of species diversity in complex environments. By combining tools such as camera traps and acoustic recorders, we can effectively monitor important seed-dispersing animals in restored areas in Madagascar, says Mahefa Andriamavosoloarisoa, PhD student at the University of Antananarivo and lead author of the study. 

Cameras placed in the canopy captured more species than those near the ground, highlighting how many animals depend on trees in the rainforest. The images showed that species richness was highest in older, protected forests and lowest in cleared areas. 

Seed-dispersing species in reforested areas

Forest areas that are not actively restored struggle to regenerate naturally. They are used for grazing or ravaged by fires. Seed-dispersing animals do not help in these areas either, as they tend to stay within existing forests. However, the researchers found that seed-dispersing species were present in replanted areas at all study sites.

– Most of the reforested areas we studied were quite young. It was therefore especially encouraging to find that several seed-dispersing species, including birds, fruit bats, primates and other mammals, are already using many of these areas. This suggests good prospects for biodiversity in the long term, says Sheila Holmes.

Ensuring that seed-dispersing species are attracted to restored areas is therefore a key part of the work to restore the rainforest, according to the researchers.

– This study highlights that long-term restoration success depends not only on planting trees, but also on restoring the ecological functions that sustain forest ecosystems, says Mahefa Andriamavosoloarisoa.

Scientific article

Biodiversity and Conservation: Camera traps and acoustic approaches are needed to monitor Malagasy seed dispersers 

The slideshow shows some of the seed-dispersing species captured on camera in the study.