camera traps work well to estimate species diversity of medium and large mammals, a recent study says. Counting the number of mammals in dense tropical forests is difficult and rare species are often missed out. Camera traps offer a new tool for finding the number of large and medium sized terrestrial mammals. But the method is not foolproof and researchers point out the importance of having an adequate camera grid size. Larger the grid size, lower the population density estimates.
For the present study, researchers looked at mammals in lowland moist Amazonian forests of Peru. Camera traps were set up for two 60-day periods. The cameras were positioned in pairs, facing each other across the trail and each pair was separated from the next by two km in a grid-like manner. The first 60-day period had 24 cameras set up and 40 cameras were used in the second period. Passive infrared cameras were used to study capture capability