This article was written by Maddy Desisto, Cecilia Giaimo, Eli Kaufman and Kara Shacklette.
The introduction of the camera trap in the early 2000s allowed us to answer the long pondered philosophical question: if a tree falls in a forest and there is a camera trap around to record it, is the camera trap a useful tool? The rise in popularity of the camera trap allowed humans to have an ever present eye, similar to Big Brother but with nature. Camera traps help researchers collect data on fauna that are typically considered “shy” when using other methods of surveying. This is because camera traps reduce impact from data collection on animal behavior.
To understand the value of camera traps compared with sight based walking surveys, we compared camera trap photos taken near Lake Eacham in October 2019 and March 2020 with a survey we completed on March 13, 2020. We found some striking differences. One being that there are many different types of fauna not picked up by these camera traps. During our walks, we saw many more birds, skinks, and musky rat-kangaroos than were captured by the camera traps. Flying birds are generally higher in the forest air, while the camera traps are typically pointed at the landscape rather than the canopy. Skinks are too small to be picked up by camera, so many more were seen during our walking surveys. While we captured 6 musky rat-kangaroos on the camera traps, we saw 10 during our field surveys. In addition to the larger animals that were seen more frequently during our walking surveys, we were also able to see many more invertebrates while walking than on film. Camera traps also do not record sounds, which adept researchers doing walking surveys may be able to interpret.
Our surveys indicated various uses and benefits for using camera traps. Camera traps seem best for small and/or medium sized mammals and ground birds. According to researchers at the New South Wales Department of Primary Industries Vertebrate Pest Research Unit, small and/or medium sized mammals are the major focus of camera trap studies. The camera is facing towards the ground so they miss everything flying above them. If a researcher is trying to measure all vertebrate fauna populations, it would be difficult to gain an accurate assessment of these creatures.
The walking surveys were conducted during light hours, while the camera traps were in operation at all times. This was a big advantage of the camera traps, which were able to capture larger critters that triggered the camera. On the other hand, walking surveys allowed us to survey an entire trail on both sides, while camera traps were set and unable to change view. Another factor, explored by researchers from Norway, was the effect of camera quality and researcher experience with camera traps. They found that when using cheaper trapping cameras, a wide range of practical problems presented themselves. Some of these problems included setup, operation, and management of data. These combined issues complicated data collection and analysis. As such, camera trapping as a method, as with any method, can be done poorly or provide insufficient data with the wrong equipment.
While camera traps have advantages, such as their tireless collection and noninvasive nature, walking surveys also have their own benefits. Walking surveys allow for a more connected method of survey so that the researcher could potentially record more audio based fauna or organisms that exist higher in the canopy. Researchers and recreational nature enthusiasts should carefully consider what they are looking for when thinking about how they want to survey nature in the future.
Further reading:
Newey et al. Limitations of recreational camera traps for wildlife management and conservation research: A practitioner’s perspective. Ambio 44, 624–635 (2015). https://doi.org/10.1007/s13280-015-0713-1
Meek et al. Are we getting the full picture? Animal responses to camera traps and implications for predator studies. Ecology and Evolution. 6:10 (2016)
https://doi.org/10.1002/ece3.2111
