A global network of spy cameras has been used to produce a mega-survey of animal diversity; the authors say it is the largest ‘camera trap’ study to date.
Some 420 cameras strapped to trees in tropical forests caught more than 51,000 images at 7 sites between 2008 and 2010, of animals from tapirs to tigers. There are snaps of gorillas curiously peering into the lens, of animals in previously unknown haunts or exhibiting previously unknown behaviours, and even of poachers walking unsuspectingly by (photos here).
The study’s main conclusion is unsurprising: the bigger a patch of protected forest, the more diverse life is within it. But there are a few curious details. The first mammals to fall prey to habitat loss, for example, seem to be the insect-eating ones — like anteaters and armadillos. The authors, led by ecologist Jorge Ahumada of Conservation International, don’t yet know why that is so.
The plummeting cost of camera technologies in recent years have made ‘camera traps’ an ever more economical way of collecting data about shy creatures in the far-flung wilderness. The BBC Wildlife Magazine has had a photo competition since last year specifically for camera trap entries (see last year’s winners). Conservation International’s Tropical Ecology Assessment and Monitoring (TEAM) Network has now set up arrays of cameras in 17 sites around the world. By carefully selecting camera locations, the pictures can be used for quantitative assessments of how many tigers (or gorillas or anteaters) live in a patch of forest, and how those populations are changing over time.
While the photos are a goldmine for ecologists, getting them is not always as easy as it seems. Installing cameras can mean weeks of hiking through rain-drenched impenetrable forest (one TEAM study site, in Uganda, is literally called the Bwindi Impenetrable Forest), with cumbersome equipment like ladders, to sites selected by a computer for their statistical randomness rather than for their ease of accessibility.
Picture caption: Central Suriname Nature Reserve, Suriname. Panthera Onca (Jaguar), a near threatened species. Of the sites researched, this one presented the highest number of species diversity (28).
This image is one of nearly 52,000 photos of 105 mammal species, taken as part of the first global camera trap mammal study done by The Tropical Ecology Assessment and Monitoring Network (TEAM)