Chronic exposure of Hawaii Island spinner dolphins (Stenella longirostris) to human activities

Habitat selection is strongly influenced by spatial variations in habitat quality and predation risk. Repeated exposure of wildlife to anthropogenic activities in important habitats may affect habitat selection, leading to negative biological consequences. We quantified the cumulative human exposure of a small, genetically-isolated and behaviourally-constrained spinner dolphin (Stenella longirostris) population, off Hawaii Island, and exposure effects on their daytime cumulative activity budget. Dolphins were exposed to human activities within 100m for 82.7% of the daytime, with a median duration of 10 min between exposure events. Individual dolphins spent on average 61.7% (SD=6.5) of their daytime resting. Of their total rest time, >90% occurred inside sheltered bays. Despite high levels of human exposure, we did not observe an effect on dolphin resting behaviour. The short intervals between exposure events likely prevent dolphins from returning to a natural resting state before the...

生境选择强烈受生境质量与捕食风险的空间变异影响。野生动物在重要生境中反复接触人类活动，可能会干扰其生境选择，进而引发负面生物学效应。本研究量化了夏威夷岛外海域一处小型、遗传隔离且行为受限的飞旋海豚（Stenella longirostris）种群的累计人类接触情况，以及人类接触对其日间累计活动时间分配的影响。该种群日间有82.7%的时间处于人类活动100米范围内，两次接触事件的间隔中位数为10分钟。单只飞旋海豚的日间休息时长平均占比达61.7%（标准差SD=6.5），其总休息时长中有超过90%发生在遮蔽性海湾内。尽管人类接触程度极高，但本研究未观测到其对飞旋海豚休息行为产生显著影响。两次接触事件的间隔过短，可能导致飞旋海豚无法在下次接触前恢复至自然休息状态……