(CNN) -- A conservation study using hidden motion-sensor cameras has revealed the secret life of mammals in some of the world's most remote forests.
It is the first study of its kind that sought to collect data on mammals living in seven different forests locations, the full results of which were published in the journal "Philosophical Transactions of the Royal Society."
Led by Dr Jorge Ahumada of the Tropical Ecology Assessment and Monitoring Network (TEAM) at Conservational International, the study captured over 50,000 images of 105 species that ranged from three-ton elephants to a 26-gram Linnaeu's Mouse Opposum.
The photos, shot between 2008 and 2010, also revealed some non-native mammals to the protected forest areas: poachers and tourists.
Protected forest regions in Uganda, Tanzania, Surinam, Laos, Costa Rica, Brazil and Indonesia were studied using 420 cameras with 60 at each site. The cameras were left for a month in each location to record passing forest-dwellers.
After cataloging the animals caught on camera, the study team concluded that smaller protected areas lead to less species diversity among mammals, with some more at risk than others.
"Protected areas matter," said Ahumada.
"The bigger the forest (mammals) live in, the higher the number and diversity of species, body sizes and diet types. "Some mammals seem more vulnerable to habitat loss than others: insect-eating mammals -- like anteaters, armadillos and some primates, are the first to disappear -- while other groups, like herbivores, seem to be less sensitive."
"The results of the study are important in that they confirm what we suspected: habitat destruction is slowly but surely killing our planet's mammal diversity."
The Central Suriname Nature Reserve had the highest number of species diversity with 28 and the Nam Kading National Protected Area in Laos presented the lowest with 13.
With 25% of mammal species under threat, according to Conservation International, Ahumada hopes that the study will help to provide a framework that others can follow to study and ultimately protect endangered mammals.
"Without a systematic, global approach to monitoring these animals and making sure the data gets to people making decisions, we are only recording their extinctions, not actually saving them," he said.