University of Zurich, Department of Evolutionary Biology and Environmental Studies, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
Sci Rep. 2020 Mar 23;10(1):5220. doi: 10.1038/s41598-020-61594-y.
Small and cryptic species are challenging to detect and study in their natural habitat. Many of these species are of conservation concern, and conservation efforts may be hampered by the lack of basic information on their ecological needs. Brown hare (Lepus europaeus) leverets - one example of such a small, cryptic and endangered animal - are notoriously difficult to detect, and therefore data on wild leverets are virtually non-existent. Novel technologies and methods such as thermal imaging and the use of wildlife detection dogs represent suitable means for the detection of such species by overcoming the problem of camouflage, using heat or scent emission respectively. Our study on brown hare leverets provides information on how to apply these new techniques successfully for the detection of small and cryptic species, thus enabling the collection of data that was previously inaccessible (e.g. behavioural observation, radio tagging). We found that the choice of method should be made according to vegetative structure. While the handheld thermal imaging camera is best used in areas with no or low vegetative cover, the thermal drone can be used up to medium vegetative cover, whereas the detection dog method is best applied where vegetation is very dense and not suitable to be searched using thermography. Being able to search all sort of different vegetation types, our combined approach enables the collection of a balanced and unbiased dataset regarding habitat type and hence selection of study specimen. We hope that the use of these new techniques will encourage research on many cryptic species that formerly have been neglected because they could not be detected using conventional methodologies.
小型和隐蔽物种在其自然栖息地中很难被发现和研究。这些物种中有许多是受到保护关注的，而由于缺乏有关其生态需求的基本信息，保护工作可能会受到阻碍。棕兔（Lepus europaeus）幼崽就是这样一个小型、隐蔽和濒危动物的例子，它们非常难以发现，因此，关于野生幼崽的数据几乎不存在。热成像和使用野生动物探测犬等新技术和方法代表了克服伪装问题的合适手段，分别利用热或气味排放来检测这些物种。我们对棕兔幼崽的研究提供了有关如何成功应用这些新技术来检测小型和隐蔽物种的信息，从而能够收集以前无法获取的数据（例如行为观察、无线电标记）。我们发现，应该根据植被结构选择方法。虽然手持式热成像相机在无植被或低植被覆盖的区域最适用，但热无人机可用于中植被覆盖区域，而探测犬方法最适用于植被非常密集且不适合使用热成像进行搜索的区域。由于能够搜索各种不同的植被类型，我们的综合方法能够收集关于栖息地类型的平衡且无偏倚的数据集，从而选择研究样本。我们希望这些新技术的使用将鼓励对许多以前因使用传统方法无法检测到而被忽视的隐蔽物种进行研究。
