Data from: Temporally and spatially partitioned behaviours of spinner dolphins: implications for resilience to human disturbance

Selective forces shape the evolution of wildlife behavioural strategies and influence the spatial and temporal partitioning of behavioural activities to maximize individual fitness. Globally, wildlife is increasingly exposed to human activities which may affect their behavioural activities. The ability of wildlife to compensate for the effects of human activities may have implications for their resilience to disturbance. Resilience theory suggests that behavioural systems which are constrained in their repertoires are less resilient to disturbance than flexible systems. Using behavioural time-series data, we show that spinner dolphins (Stenella longirostris) spatially and temporally partition their behavioural activities on a daily basis. Specifically, spinner dolphins were never observed foraging during daytime, where resting was the predominant activity. Travelling and socialising probabilities were higher in early mornings and late afternoons when dolphins were returning from or preparing for nocturnal feeding trips, respectively. The constrained nature of spinner dolphin behaviours suggests they are less resilient to human disturbance than other cetaceans. These dolphins experience the highest exposure rates to human activities ever reported for any cetaceans. Although spinner dolphins still inhabit these bays after >30 years, recent abundance estimates (2011 and 2012) are lower than all previous estimates (1979-1981, 1989-1992 and 2003), indicating a possible long-term impact. Quantification of the spatial and temporal partitioning of wildlife behavioural schedules provides critical insight for conservation measures that aim to mitigate the effects of human disturbance.

选择压力塑造了野生生物行为策略的演化，并影响行为活动的时空分区，以最大化个体适合度。全球范围内，野生生物正日益暴露于人类活动中，这些活动可能对其行为活动产生影响。野生生物补偿人类活动影响的能力，可能会影响其对扰动的恢复力。恢复力理论指出，行为谱受限的行为系统，相较于灵活的行为系统，对扰动的恢复力更弱。本研究利用行为时间序列数据，证实长吻原海豚（spinner dolphins, Stenella longirostris）会每日对自身行为活动进行时空分区。具体而言，研究未观测到长吻原海豚在日间开展觅食活动，此时休息为其主要行为。清晨与傍晚时段，游动与社交行为的发生概率更高——前者对应海豚结束夜间觅食后的返程阶段，后者则对应其为夜间觅食做准备的阶段。长吻原海豚行为模式的受限性，表明其相较于其他鲸类，对人类扰动的恢复力更弱。这类海豚所承受的人类活动暴露水平，为所有已报道鲸类动物中的最高值。尽管长吻原海豚在该海湾栖息已超过30年，但近期（2011年与2012年）的种群数量估算结果，均低于此前所有时段（1979-1981年、1989-1992年及2003年）的估算值，这暗示存在长期潜在影响。对野生生物行为节律的时空分区进行量化，可为旨在减缓人类扰动影响的保护措施提供关键认知。