An improved camera trap for amphibians, reptiles, small mammals, and large invertebrates

Abstract

Camera traps are valuable sampling tools commonly used to inventory and monitor wildlife communities but are challenged to reliably sample small animals. We introduce a novel active camera trap system enabling the reliable and efficient use of wildlife cameras for sampling small animals, particularly reptiles, amphibians, small mammals and large invertebrates. It surpasses the detection ability of commonly used passive infrared (PIR) cameras for this application and eliminates problems such as high rates of false triggers and high variability in detection rates among cameras and study locations. Our system, which employs a HALT trigger, is capable of coupling to digital PIR cameras and is designed for detecting small animals traversing small tunnels, narrow trails, small clearings and along walls or drift fencing.

Automatic detection of small PIT-tagged animals using wildlife crossings

“…For insects, monitoring with camera traps is still emerging [43]. The quality of the recorded pictures/videos and issues of detectability currently limit the effectiveness of camera traps for small organisms; however, technological developments may improve their use for small ectothermic animals [18][19][20][21]. The fine-scale movements of amphibians have been recording with individuals brushed with fluorescent pigments, leaving a detectable track on the ground [22].…”

“…However, for small animals, the size of the emitter and battery limits the use of radio-tracking [15], making it impossible to record successive positions within the tunnel during the crossing. Camera traps are widely use to monitor tunnels use (reviewed in [17] and [18]), and the increasing quality of the recorded pictures/videos and automatic detection devices allow their use for small ectothermic organisms [19][20][21]. Moreover, the precise trajectory of amphibian during short-term movements can be recording thanks to fluorescent pigments [22,23].…”

Camera‐trapping version 3.0: current constraints and future priorities for development

“…ectothermic species and species living in hot environments). Hobbs and Brehme () proposed a proprietary active infrared system for specifically targeting small animals (small mammals, amphibians, reptiles and large invertebrate species), but it is unsuitable for medium‐ and large‐sized animals. Camera trap systems that separate the camera from the triggering mechanism might also be a promising approach for small‐bodied species (e.g.…”

It's time to listen: there is much to be learned from the sounds of tropical ecosystems

“…). That said, camera trapping is restricted to this subset of species (but see Hobbs & Brehme ) and the detection range is relatively limited. PAM has the additional benefit of having broader detection ranges [e.g., maximum 1 km detection radius calculated for primate sounds (Kalan et al .…”

“…The related technique of camera trapping has greatly improved our capacity to estimate species composition, abundance, and density of medium to large-bodied mammals and birds-groups that are difficult to study using traditional methods-in terrestrial (Burton et al 2015) and arboreal habitats (Gregory et al 2014). That said, camera trapping is restricted to this subset of species (but see Hobbs & Brehme 2017) and the detection range is relatively limited. PAM has the additional benefit of having broader detection ranges [e.g., maximum 1 km detection radius calculated for primate sounds (Kalan et al 2015); up to many km depending on frequency, microphone height, and habitat type (Darras et al 2016)] and sampling a wider range of taxonomic groups .…”