Introduction
Survey of camera traps used by UK (non-) government agencies and the international research community
Camera trap quality | UK NGOs and governmental organisations | Peer-reviewed literature | ||||
---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | ||
Low-end (<300 USD) |
(38 %, n = 10) | |||||
Mid-range (301–370 USD) |
(23 %, n = 6) | |||||
High-end (371–740 USD) | – | – | – |
(38 %, n = 10) |
Case studies
Case Study 1—Monitoring wildlife activity around deer carcasses: Researcher experiences
Deployment issues
Operational issues
Data management issues
Problems during use | Consequences | Case study |
---|---|---|
Deployment | ||
Fiddly navigation—small buttons | Increasing time needed for fieldwork and increased error rate | 1, 2 |
Screen is difficult to read in low light or bright sunlight | Increasing time needed for fieldwork and increased error rate | 1, 2 |
Synchronising time consuming and awkward | Increased setup and deployment and approximate synchronisation | 1, 2 |
Keeping track of cameras and images (no meta-data) | Increased post-collection processing time, risk of introducing errors and data loss | 1, 2 |
Losing settings during transit | Increasing time needed for fieldwork, error rate, and loss of data if not detected and corrected | 1 |
Walk-by test requires downloading image on laptop in the field | Time consuming and requires access to laptop in the field | 1, 2 |
Operational | ||
Excessive use of flash and frequent triggering (mostly generating false positives) | Swift depletion of batteries; requiring additional field visits to replace batteries; increased costs | |
Internal clocks would commonly reset to factory settings | Loss of useable data or loss of data quality | 1 |
Snow/sleet and ice build-up and condensation on lens | Poor quality or no usable imagery | 1, 2 |
Camera failure due to unknown causes | Loss of data | 1, 2 |
Loss of clock synchrony between cameras, with rate of divergence changing over deployment period | Loss of useable data or loss of data quality | 1, 2 |
Data management | ||
Loss of meaningful date-time stamps | Rendered large volumes of data useless (and sampling effort could not be assessed) | 1, 2 |
Large number of images | Problems sharing data. Difficulties cataloguing and analysing | 1, 2 |
High proportion of false positives | Drains battery power, on-board storage, network storage, time for processing, data extraction | 1 |
Differences in the number of animal detections among cameras monitoring the same carcass | Missed data due to questionable effectiveness of camera traps | 1, 2 |
Highly variable proportion of false positives/negatives between locations, time periods and cameras | Questioning camera traps as a research tool. Potential biases, systematic difference between cameras | 1, 2 |
Lack of tools to either simultaneously log or match external data sources to imagery | Labour-intensive to extract and match images from multiple cameras with meteorological data | 2 |
Case Study 2—Determining the causes of false positives: Trials with sheep
Deployment issues
Operational issues
Data management issues
Vegetation | Camera height (m) | Time-lapse camera | Motion-activated camera | ||
---|---|---|---|---|---|
Total no. imagesa
| No. sheep visits | No. sheep visits detected | False negative records (%)b
| ||
Short grass | 1.2 | 181 | 95 | 30 | 68 |
Tall heather | 0.6 | 181 | 71 | 27 | 62 |
Tall heather | 1.2 | 181 | 71 | 36 | 49 |