When most people imagine a wildlife researcher, they probably picture someone trekking through nature and jotting down observations about the animals around them.
While this kind of fieldwork is still done today, many researchers now study wildlife with motion-sensing cameras that take photos whenever an animal wanders into frame. Typically, these “camera traps,” as they are known, are set up on the ground and only capture the species that spend time at ground level.
Jennifer Moore, a postdoctoral researcher at the University of Florida, hypothesized that installing camera traps up in trees, as well as on the ground, would give a more complete picture of the wildlife in an area. She also wanted to know how camera trapping would compare to the older way of surveying wildlife where researchers walk a transect line and record animal sightings.
In a new study, Moore and her collaborators found that a combination of ground and tree camera traps effectively documented how many different species of animals are in an area, including elusive species that may be difficult for human observers to spot.
“Because these cameras are working all day and night, they capture animals moving through the landscape that may have been missed by the human eye,” said Moore, whose postdoctoral appointment is in the UF/IFAS department of wildlife ecology and conservation. “Because of this, camera traps are more likely to document rare species of conservation concern.”
For the study, Moore and her colleagues set up more than 100 camera traps in a tropical, forested area within Nyungwe National Park in Rwanda. Nyungwe National Park is a top priority site for biodiversity conservation because it contains many globally threatened and endangered species.
About half the cameras were set up on the ground, the other half in trees. Over 30 days, the cameras captured more than 27,000 photos of wildlife representing 35 different species, including the rare Central African oyan, a small, catlike mammal that lives in trees and is active at night. This was the first time the Central African oyan has been seen in Nyungwe National Park.
The oyan sighting demonstrates the value of camera traps for monitoring species that live in trees, Moore said. If park managers know a species is living in the park, they can take steps to conserve it, she said.
Camera traps are also a tool for gauging what ecologists call “species richness,” the measure of how many different species are in an area, Moore explained.
“Species richness tells us about the health of an ecosystem. A higher species richness is generally a sign of a more stable ecosystem,” Moore said. Camera trapping can help scientists get a better idea of species richness and ultimately inform how species are conserved, she said.
Camera traps in trees are one way wildlife ecologists are using technology to collect more data with less manpower. However, even with the help of the cameras, researchers must still hike through the environment install them — or, in the case of Moore’s team, get good at climbing trees.
In addition to Moore, the study’s authors include Bill Pine, UF professor of wildlife ecology and conservation; Felix Mulindahabi, Protais Niyigaba and Gratien Gatorano of the Wildlife Conservation Society; Michel Masozera of the World Wide Fund for Nature; and Lydia Beaudrot of Rice University.