Schofield Gail, Dickson Liam C D, Westover Lucy, Dujon Antoine M, Katselidis Kostas A
School of Biological and Chemical Sciences Queen Mary University of London London UK.
School of Biological Sciences University of Bristol Bristol UK.
Evol Appl. 2021 Jul 17;14(10):2516-2526. doi: 10.1111/eva.13277. eCollection 2021 Oct.
Quantifying the extent to which animals detect and respond to human presence allows us to identify pressure (disturbance) and inform conservation management objectively; however, obtaining baselines against which to compare human impact is hindered in areas where human activities are already well established. For example, Zakynthos Island (Greece, Mediterranean) receives around 850,000 visitors each summer, while supporting an important loggerhead sea turtle rookery (~300 individuals/season). The coronavirus (COVID-19)-driven absence of tourism in May-June 2020 provided an opportunity to evaluate the distribution dynamics of this population in the absence (2020) vs. presence (2018 and 2019) of visitors using programmed unmanned aerial system (UAS) surveys. Ambient sea temperature transitioned from suboptimal for breeding in May to optimal in late June, with turtle distribution appearing to shift from shallow (to benefit from waters 3-5°C above ambient) to deeper waters in 2018 and 2019, but not 2020. The 2020 data set demonstrated that increased tourism pressure, not temperature, drives turtles offshore. Specifically, >50% of turtles remained within 100 m of shore at densities of 25-50 visitors/km, even when sea temperature rose, with 2018 and 2019 data supporting this trend. Reduced access to warmer, nearshore waters by tourism could delay the onset of nesting and increase the length of the egg maturation period between nesting events (internesting interval) at this site. A coastal refuge zone could be delimited in May-June where touristic infrastructure is minimal, but also where turtles frequently aggregate. In conclusion, sea turtles appear capable of perceiving changes in the level of human pressure at fine spatial and temporal scales and adjusting their distribution accordingly.
量化动物检测并对人类存在做出反应的程度，能使我们确定压力（干扰），并为保护管理提供客观依据；然而，在人类活动已然确立的地区，获取用于比较人类影响的基线受到了阻碍。例如，扎金索斯岛（希腊，地中海地区）每年夏天接待约85万游客，同时这里也是一个重要的蠵龟繁殖地（约300只/繁殖季）。2020年5月至6月因新冠疫情导致旅游业停滞，这为利用程控无人机系统（UAS）调查评估该种群在游客缺席（2020年）与在场（2018年和2019年）情况下的分布动态提供了契机。海水环境温度从5月不利于繁殖转变为6月下旬适宜繁殖，蠵龟的分布在2018年和2019年似乎从浅水区（以受益于比环境温度高3 - 5°C的水域）转移到了深水区，但2020年并非如此。2020年的数据集表明，是旅游压力增加而非温度变化驱使蠵龟前往近海。具体而言，即使海水温度上升，在游客密度为25 - 50人/公里时，超过50%的蠵龟仍留在距离海岸100米范围内，2018年和2019年的数据也支持这一趋势。旅游业导致蠵龟难以进入温暖的近岸水域，可能会推迟筑巢时间，并延长该繁殖地两次筑巢事件之间的卵成熟周期（窝间距）。可以在5月至6月划定一个沿海避难区，这里旅游基础设施最少，但也是蠵龟经常聚集的地方。总之，蠵龟似乎能够在精细的空间和时间尺度上感知人类压力水平的变化，并相应地调整其分布。
