Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1090 GE, Amsterdam, The Netherlands.
Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, Fife KY16 9LZ, United Kingdom.
Ecol Appl. 2019 Jul;29(5):e01903. doi: 10.1002/eap.1903. Epub 2019 May 16.
Understanding the full scope of human impact on wildlife populations requires a framework to assess the population-level repercussions of nonlethal disturbance. The Population Consequences of Disturbance (PCoD) framework provides such an approach, by linking the effects of disturbance on the behavior and physiology of individuals to their population-level consequences. Bio-energetic models have been used as implementations of PCoD, as these integrate the behavioral and physiological state of an individual with the state of the environment, to mediate between disturbance and biological significant changes in vital rates (survival, growth, and reproduction). To assess which levels of disturbance lead to adverse effects on population growth rate requires a bio-energetic model that covers the complete life cycle of the organism under study. In a density-independent setting, the expected lifetime reproductive output of a single female can then be used to predict the level of disturbance that leads to population decline. Here, we present such a model for a medium-sized cetacean, the long-finned pilot whale (Globicephala melas). Disturbance is modeled as a yearly recurrent period of no resource feeding for the pilot whale female and her calf. Short periods of disturbance lead to the pre-weaned death of the first one or more calves of the young female. Higher disturbance levels also affect survival of calves produced later in the life of the female, in addition to degrading female survival. The level of disturbance that leads to a negative population growth rate strongly depends on the available resources in the environment. This has important repercussion for the timing of disturbance if resource availability fluctuates seasonally. The model predicts that pilot whales can tolerate on average three times longer periods of disturbance in seasons of high resource availability, compared to disturbance happening when resources are low. Although our model is specifically parameterized for pilot whales, it provides useful insights into the general consequences of nonlethal disturbance. If appropriate data on life history and energetics are available, it can be used to provide management advice for specific species or populations.
了解人类活动对野生动物种群的全面影响需要一个框架来评估非致死性干扰对种群水平的影响。干扰对种群的影响（PCoD）框架提供了这样一种方法，通过将干扰对个体行为和生理的影响与其种群水平的后果联系起来。生物能量模型已被用作 PCoD 的实现，因为这些模型将个体的行为和生理状态与环境状态联系起来，在干扰和重要生命率（生存、生长和繁殖）的生物学变化之间进行调解。为了评估哪些干扰水平会对种群增长率产生不利影响，需要一个涵盖所研究生物完整生命周期的生物能量模型。在密度独立的情况下，单个雌性的预期终生繁殖输出可以用来预测导致种群下降的干扰水平。在这里，我们为一种中型鲸目动物，长鳍领航鲸（Globicephala melas）提出了这样一个模型。干扰被建模为领航鲸雌性及其幼鲸每年周期性的无资源进食期。短暂的干扰会导致幼鲸死亡，甚至使雌性在生命后期生产的幼鲸死亡。更高的干扰水平还会影响到雌性的生存，除了降低雌性的生存能力。导致种群负增长率的干扰水平强烈取决于环境中可用资源的数量。如果资源可用性随季节波动，这对干扰的时间安排有重要影响。该模型预测，与资源匮乏时相比，在资源丰富的季节，领航鲸平均可以忍受干扰时间长三倍。虽然我们的模型是专门针对领航鲸进行参数化的，但它为非致死性干扰的一般后果提供了有用的见解。如果有关于生活史和能量学的适当数据，它可以用于为特定物种或种群提供管理建议。
