A comparison of camera trap and permanent recording video camera efficiency in wildlife underpasses. Issue 18 (11th August 2017)

• Record Type: Journal Article
• Authors: Jumeau, Jonathan; Petrod, Lana; Handrich, Yves
• Is Part Of: Ecology and evolution. Volume 7:Issue 18(2017:Oct.)
• Page Start: 7399
• Page End: 7407
• Publication Date: 2017-08-11
• Subjects: camera trapping -- false trigger -- monitoring study -- small mammals -- triggered cameras -- wildlife crossings; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.3149
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: In the current context of biodiversity loss through habitat fragmentation, the effectiveness of wildlife crossings, installed at great expense as compensatory measures, is of vital importance for ecological and socio‐economic actors. The evaluation of these structures is directly impacted by the efficiency of monitoring tools (camera traps…), which are used to assess the effectiveness of these crossings by observing the animals that use them. The aim of this study was to quantify the efficiency of camera traps in a wildlife crossing evaluation. Six permanent recording video systems sharing the same field of view as six Reconyx HC600 camera traps installed in three wildlife underpasses were used to assess the exact proportion of missed events ( event being the presence of an animal within the field of view), and the error rate concerning underpass crossing behavior (defined as either Entry or Refusal ). A sequence of photographs was triggered by either animals ( true trigger ) or artefacts ( false trigger ). We quantified the number of false triggers that had actually been caused by animals that were not visible on the images ("false" false triggers). Camera traps failed to record 43.6% of small mammal events (voles, mice, shrews, etc.) and 17% of medium‐sized mammal events. The type of crossing behavior ( Entry or Refusal ) was incorrectly assessed in 40.1% of events, with a higher error rate for entries than for refusals. Among the 3.8% of false triggers, 85% of them were "false" false triggers. This study indicates a global underestimation of the effectiveness of wildlife crossings for small mammals. Means to improve the efficiency are discussed. Abstract : The efficiency of camera traps was studied in the context of small‐/medium‐sized wildlife underpass monitoring. A permanent recording video system revealed the number of animals missed by Reconyx HC600 camera traps. Cameras traps detected 57.8% of the small mammals using classical detection parameters. The crossing behavior (Entry or Refusal) was incorrectly identified in 40.1% of events. The permanent video recording showed that 85% of the photos without an animal were in fact triggered by an animal. This study indicates a global underestimation of the effectiveness of wildlife underpasses for small mammals.