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View the slideshow that your teacher shows the class of pictures of mammals gathered with camera traps from 3 different continents.
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Write a paragraph about your reaction to what you viewed in your science notebook.
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View the slideshow again. This time, your teacher will tell you the name of each animal and which country it comes from.
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Discuss your reactions with the class.
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Read the summary of the groundbreaking camera trap study and discuss its major points.
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Working in your small groups identify 3-5 main points from the article and share with your class.
Tropical Ecology Assessment & Monitoring Network groundbreaking paper on tropical mammal diversity
Adapted for students from: Ahumada, J.A., C.E.F. Silva, K. Gajapersad, C. Hallam, J. Hurtado, E. Martin, A. McWilliam, B. Mugerwa, T. O’Brien, F. Rovero, D. Sheil, W.R. Spironello, N. Winarni and S.J. Andelman. 2011. Community structure and diversity of tropical forest mammals: Data from a global camera trap network. Philosophical Transactions of the Royal Society B 366: 2703-2711.
Introduction
Scientists from Africa, Asia and Latin America participated in a study of tropical forest mammals using camera traps. Camera traps are hidden cameras set up by researchers in the forest to "capture" photographs of animals when they walk by. This study examines communities of mammals from seven tropical forest sites in the countries of Uganda, Tanzania, Indonesia, Lao PDR, Suriname, Brazil and Costa Rica. These forest sites represent continuous and fragmented forests.

Figure 1. A map of the world highlighting the countries where camera trap data were collected.
In these forests terrestrial mammals make up communities of species with diverse trophic groups and body sizes. This diversity (usually called functional diversity) is important to the ecosystem. Animals play many important roles in the forest, including spreading seeds from plants, cycling nutrients important for plants to grow and keeping plant-eating animals at healthy levels.
Methods
TEAM scientists set up camera traps at 60 points in a grid (see figure 1) covering 120 square kilometers. Cameras stay in the forest for 30 days taking pictures of animals during the dry season. In an effort to photograph as many animals as possible, researchers place the cameras near animal trails.

Figure 2. Example of camera trap grid for the Central Suriname Nature Reserve.
This study examines camera trap data from seven TEAM sites: Bwindi National Park (Uganda), Udzungwa Mountains National Park (Tanzania), Bukit Barisan Selatan National Park (Indonesia), Nam Kading National Protected Area (Lao PDR), Central Suriname Nature Reserve (Suriname), Manaus (Brazil) and Volcan Barva Transect (Costa Rica).
Each site has been classified as being contained within a landscape of continuous habitat, partially-fragmented habitat’and highly fragmented habitat. Forest fragmentation refers to patches of forest being broken into smaller pieces. This is often caused by human activities, such as cutting down trees to plant crops or raise cattle and can affect forest plants and animals. Photographed animals were assigned into different trophic groups: carnivore, herbivore, insectivore and omnivore.
Results
All together 105 mammal species were identified from 51,949 camera trap images from the seven sites. Nam Kading had the lowest species richness (13 species) and the Central Suriname Nature Reserve had the highest species richness (28 species). Sites within highly fragmented forests contained less species than sites in partially fragmented or continuous forests. Insectivores and omnivores are affected by fragmentation most, but all trophic groups decline in highly fragmented sites.
Most of the species photographed were omnivores or herbivores, there were fewer insectivores and carnivores found. At most sites the dominant species was an herbivore.
The size of the protected area was also found to impact the number of species found. Smaller protected areas tend to be surrounded by human-impacted lands to a greater extent than larger protected areas and tend to have few species of mammals and less diverse terrestrial mammal communities. Nam Kading, in Lao PDR, is an exception. Fewer species were found in Nam Kading than other sites of similar size. This may be due to a history of hunting pressure in this forest.
Discussion + Conclusion
Fragmentation affects species diversity and richness, but it is not known if this is due to loss of habitat, loss of food, hunting pressure or a combination.
These data provide a baseline of mammal community composition in seven tropical forests. Future studies can examine trends and patterns over time.