School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia.
FAUNA Research Alliance, Kahibah, New South Wales, Australia.
PLoS One. 2020 Nov 16;15(11):e0242204. doi: 10.1371/journal.pone.0242204. eCollection 2020.
Koalas (Phascolarctos cinereus) are cryptic and currently face regional extinction. The direct detection (physical sighting) of individuals is required to improve conservation management strategies. We provide a comparative assessment of three survey methods for the direct detection of koalas: systematic spotlighting (Spotlight), remotely piloted aircraft system thermal imaging (RPAS), and the refined diurnal radial search component of the spot assessment technique (SAT). Each survey method was repeated on the same morning with independent observers (03:00-12:00 hrs) for a total of 10 survey occasions at sites with fixed boundaries (28-76 ha) in Port Stephens (n = 6) and Gilead (n = 1) in New South Wales between May and July 2019. Koalas were directly detected on 22 occasions during 7 of 10 comparative surveys (Spotlight: n = 7; RPAS: n = 14; and SAT: n = 1), for a total of 12 unique individuals (Spotlight: n = 4; RPAS: n = 11; SAT: n = 1). In 3 of 10 comparative surveys no koalas were detected. Detection probability was 38.9 ± 20.03% for Spotlight, 83.3 ± 11.39% for RPAS and 4.2 ± 4.17% for SAT. Effective detectability per site was 1 ± 0.44 koalas per 6.75 ± 1.03 hrs for Spotlight (1 koala per 6.75 hrs), 2 ± 0.38 koalas per 4.35 ± 0.28 hrs for RPAS (1 koala per 2.18 hrs) and 0.14 ± 0.14 per 6.20 ± 0.93 hrs for SAT (1 koala per 43.39 hrs). RPAS thermal imaging technology appears to offer an efficient method to directly survey koalas comparative to Spotlight and SAT and has potential as a valuable conservation tool to inform on-ground management of declining koala populations.
树袋熊（Phascolarctos cinereus）是一种隐蔽的动物，目前正面临区域性灭绝。为了改善保护管理策略，需要直接检测（物理观察）个体。我们对三种直接检测树袋熊的调查方法进行了比较评估：系统聚光灯（Spotlight）、远程驾驶飞机系统热成像（RPAS）和现场评估技术（SAT）的改进日间辐射搜索组件。每个调查方法都由独立的观察者在同一天早上（03:00-12:00 小时）重复进行，总共在新南威尔士州波特斯普林斯（n = 6）和吉拉德（n = 1）的固定边界（28-76 公顷）地点进行了 10 次调查。在 2019 年 5 月至 7 月期间，在 7 次比较调查中的 10 次中直接检测到树袋熊 22 次，总共检测到 12 个独特个体（Spotlight：n = 4；RPAS：n = 11；SAT：n = 1）。在 10 次比较调查中的 3 次中没有检测到树袋熊。Spotlight 的检测概率为 38.9 ± 20.03%，RPAS 为 83.3 ± 11.39%，SAT 为 4.2 ± 4.17%。每个地点的有效可检测性为 Spotlight 每 6.75 ± 1.03 小时 1 ± 0.44 只树袋熊（每 6.75 小时 1 只），RPAS 每 4.35 ± 0.28 小时 2 ± 0.38 只树袋熊（每 2.18 小时 1 只），SAT 每 6.20 ± 0.93 小时 0.14 ± 0.14 只（每 43.39 小时 1 只）。RPAS 热成像技术似乎是一种直接调查树袋熊的有效方法，与 Spotlight 和 SAT 相比具有优势，并且有可能成为一种有价值的保护工具，为下降的树袋熊种群提供实地管理信息。
