Dawlings Finella M E, Mackay Claire, Humphrey Morgan, Mitchell William F, Sorrell Karina J, Sanchez Sonia, Viola Benjamin M, Clarke Rohan H
School of Biological Sciences Monash University Clayton Victoria Australia.
Ecol Evol. 2023 Jul 21;13(7):e10331. doi: 10.1002/ece3.10331. eCollection 2023 Jul.
Detection is essential to studying and monitoring wild animals; however, detection is challenging for small endotherms that are nocturnal or best detected at night. Techniques such as trapping or spotlighting disturb focal species, and the effectiveness of spotlighting can be limited for cryptic species, resulting in low detection rates that hinder our ability to monitor and study some endotherms at night. Thermal scanners detect infrared wavelengths not otherwise visible to humans. With improvements in equipment size and cost, thermal scanners have emerged as a valuable tool for passive detection of endotherms. Here we seek to provide objective guidance on thermal tool selection to practitioners who wish to adopt such tools to detect and monitor small endotherms. We compared the efficacy of three handheld thermal scanners (of varying resolutions) and a traditional spotlight for detecting small, cryptic endotherms at night. Random arrays of artificially heated small bird models (representing small, cryptic endotherms) were established along transects in native grasslands that support a range of small threatened endotherms, including the Critically Endangered Plains-wanderer (). Transects were independently surveyed by five observers, blind to model locations and model density. Performance measures representing detection capability were assessed for all devices, and usability of each device was assessed with a survey completed by all observers. Detection rates, detection distances, and survey accuracy were greater for thermal scanners with resolutions of 320 × 240 and 640 × 480 than for the spotlight. A low-resolution thermal scope (160 × 120) performed poorly for all performance measures. There was a consensus among users that a video camera-style thermal scanner was most comfortable to hold and view while traversing the transect, as opposed to thermal scopes where users look directly through the lens. These results suggest that high-resolution thermal scanners (≥320 × 240) provide improved detection capabilities compared to traditional spotlights. Higher detection rates provide opportunities for detecting and monitoring small endotherms at night where this was once difficult or impossible.
检测对于研究和监测野生动物至关重要；然而，对于夜间活动或在夜间最易被检测到的小型恒温动物来说，检测具有挑战性。诸如诱捕或聚光灯照明等技术会干扰目标物种，而且聚光灯照明对于隐秘物种的有效性可能有限，导致检测率较低，这阻碍了我们在夜间监测和研究某些恒温动物的能力。热成像扫描仪能检测人类无法看到的红外波长。随着设备尺寸和成本的改进，热成像扫描仪已成为被动检测恒温动物的一种有价值的工具。在此，我们旨在为希望采用此类工具来检测和监测小型恒温动物的从业者提供关于热成像工具选择的客观指导。我们比较了三款手持热成像扫描仪（分辨率不同）和传统聚光灯在夜间检测小型隐秘恒温动物的效果。在原生草原的样带上建立了人工加热的小型鸟类模型（代表小型隐秘恒温动物）的随机阵列，该原生草原中有一系列小型濒危恒温动物，包括极度濒危的平原 wanderer（此处原文未给出该动物中文名）。样带由五名观察者独立进行调查，他们对模型位置和模型密度不知情。对所有设备评估了代表检测能力的性能指标，并通过所有观察者完成的一项调查评估了每个设备的可用性。分辨率为320×240和640×480的热成像扫描仪的检测率、检测距离和调查准确性均高于聚光灯。低分辨率热成像瞄准镜（(160×120)）在所有性能指标上表现不佳。用户们一致认为，与用户直接通过镜头观察的热成像瞄准镜相比，视频摄像机式热成像扫描仪在穿越样带时握持和观察最舒适。这些结果表明，与传统聚光灯相比，高分辨率热成像扫描仪（≥320×240）提供了更好的检测能力。更高的检测率为在夜间检测和监测小型恒温动物提供了机会，而在此之前这曾经是困难的或不可能的。
