Cole Emma-Louise, Waggitt James J, Hedenstrom Anders, Piano Marco, Holton Mark D, Börger Luca, Shepard Emily L C
Department of Biosciences, Swansea University, Swansea, UK.
School of Ocean Sciences, Bangor University, Menai Bridge, UK.
Integr Zool. 2019 Jan;14(1):4-16. doi: 10.1111/1749-4877.12327.
Animal-attached technologies can be powerful means to quantify space use and behavior; however, there are also ethical implications associated with capturing and instrumenting animals. Furthermore, tagging approaches are not necessarily well-suited for examining the movements of multiple individuals within specific, local areas of interest. Here, we assess a method of quantifying animal space use based on a modified theodolite with an inbuilt laser rangefinder. Using a database of >4200 tracks of migrating birds, we show that detection distance increases with bird body mass (range 5 g to >10 kg). The maximum distance recorded to a bird was 5500 m and measurement error was ≤5 m for targets within this distance range: a level comparable to methods such as GPS tagging. We go on to present a case study where this method was used to assess habitat selection in seabirds operating in dynamic coastal waters close to a tidal turbine. Combining positional data with outputs from a hydrographic model revealed that great cormorants (Phalacrocorax carbo) appeared to be highly selective of current characteristics in space and time, exploiting areas where mean current speeds were <0.8 m·s and diving at times when turbulent energy levels were low. These birds also oriented into tidal currents during dives. Taken together, this suggests that collision risks are low for cormorants at this site, as the 2 conditions avoided by cormorants (high mean current speeds and turbulence levels) are associated with operational tidal turbines. Overall, we suggest that this modified theodolite system is well-suited to the quantification of movement in small areas associated with particular development strategies, including sustainable energy devices.
动物附着技术可以成为量化空间利用和行为的有力手段；然而，捕捉和给动物安装仪器也存在伦理问题。此外，标记方法不一定非常适合研究特定局部感兴趣区域内多个个体的活动。在此，我们评估一种基于带有内置激光测距仪的改良经纬仪来量化动物空间利用的方法。利用一个包含超过4200条候鸟迁徙轨迹的数据库，我们发现探测距离随着鸟类体重增加而增加（范围从5克到超过10千克）。记录到的鸟类最大距离为5500米，在此距离范围内目标的测量误差≤5米：这一水平与GPS标记等方法相当。我们接着展示一个案例研究，该方法被用于评估在靠近潮汐涡轮机的动态沿海水域活动的海鸟的栖息地选择。将位置数据与水文模型的输出结果相结合表明，普通鸬鹚（Phalacrocorax carbo）似乎在空间和时间上对水流特征具有高度选择性，利用平均水流速度<0.8米·秒的区域，并在湍流能量水平较低时潜水。这些鸟类在潜水时也会顺着潮流方向。综合来看，这表明该地点的鸬鹚碰撞风险较低，因为鸬鹚避开的两个条件（高平均水流速度和湍流水平）与运行中的潮汐涡轮机相关。总体而言，我们认为这种改良的经纬仪系统非常适合量化与特定发展战略相关的小区域内的活动，包括可持续能源装置。
