They might not know they’re on candid camera, and they certainly don’t smile, but wildlife caught on camera are helping scientists confirm their existence and prove forest protection works.
Camera traps have become more commonly used to find out what wild animals do while no-one’s watching, but a study spanning tropical regions in Centra and South America, South-East Asia and Africa has put the pictures to work establishing the worth of forest reserves.
The study, published today in PLOS Biology, monitored 244 ground-dwelling species across 15 protected areas. From over 1000 cameras, more than 2.5 million photos were analysed which showed that 22% of populations decreased, 17% increased and 22% remained constant (the remainder were seen too infrequently to draw conclusions on any population change).
Based on three measures of biodiversity – occupancy, richness and evenness – the Tropical Ecology Assessment and Monitoring Network (TEAM) researchers concluded that diversity did not decline overall in the protected areas.
TEAM Network executive director Jorge Ahumada said the results showed that protected areas played an important role in maintaining biodiversity.
“Our study reflects a more optimistic outlook about the effectiveness of protected areas. For the first time we are not relying on disparate data sources, but rather using primary data collected in a standardized way across a range of protected areas throughout the world.”
And the findings haven’t just been academic. In Uganda’s Bwindi Impenetrable Forest, the researchers noticed a decline in the area occupied by the African golden cat – an International Union for Conservation of Nature (IUCN) vulnerable species.
Those areas were heavily used by tourists, so park managers redirected travellers to alternate trails and sightings of the African golden cat increased.
Camera traps have become more frequently used in wildlife surveys, especially when looking for rare or elusive species.
In December, researchers working in South Sudan announced they had taken the first pictures of forest elephants, Loxodonta cyclotis, ever captured in the area.
University of Michigan professor Lydia Beaudrot said species loss was especially high in tropical regions “where most species live and where biodiversity threats are severe”.
“Protected areas, such as national parks, are the cornerstone of species conservation, but whether protected areas really sustain animal populations and prevent extinction has been debated. This is particularly true for tropical areas, which are oftentimes understudied and for which there is a lack of high-quality data.”
Monitoring mammal and bird populations and species diversity using the standardised camera trap method could prove a first glance at overall forest health and how the species in those forests are getting by. The TEAM Network researchers hope their system will be extended to monitor other geographic areas as a solution to measure changes in on-the-ground biodiversity and ecosystem health outcomes.
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All images courtesy of the Tropical Ecology Assessment and Monitoring Network (TEAM).