The effects of artificial nighttime lighting on moth visual ecology and survival

从强度和全球覆盖范围来看，来自路灯和其他来源的夜间人造光正以前所未有的速度增长。几乎可以肯定，这种照明对夜行动物的视觉生态有广泛的影响，并与整个欧洲夜间飞蛾数量的急剧下降有关。许多夜间活动的飞蛾利用其出色的弱光色彩视觉在夜间定位花朵，并且是全球花粉运输网络的主要贡献者。最近的研究强调了人工光源可能干扰夜间传粉者的视力，改变它们在景观中的丰度和分布，影响授粉质量，并改变它们对捕食者的反应。对光源的吸引也是许多昆虫死亡的一个众所周知的原因。然而，许多研究仍然是相关的，或者局限于特定的物种，并且缺乏基本的行为理解，即不同的人工光源如何影响特定的视觉相互作用，而这些相互作用是飞蛾和它们授粉的植物生存的关键。我们的视觉建模工作发现了光线类型、光线强度和物体颜色之间意想不到的相互作用，例如，允许同一朵花根据光线强度从高度显眼的颜色转变为与背景匹配的颜色。这种影响可能会从根本上破坏传粉者的行为，而这种行为在野外几乎不可能检测到，对植物也会产生未知的后果。我们的模型还表明，人造光可能会干扰飞蛾抵御捕食者的防御能力，导致它们在白天休息时选择不好的背景颜色。该项目将确定夜间人造光如何影响飞蛾视觉生态的三个关键方面：i)花信号：我们将使用半自然实验来研究我们的视觉建模预测，测试光类型、光强度和花颜色之间复杂的相互作用对视觉引导的花探测和处理行为的影响。ii)飞行行为：使用模拟观看条件的系绳飞行实验将用于确定不同飞蛾物种如何对人造光和背景场景外观的不同方面做出反应，以及哪些假设的定向机制受到影响。具体来说，这将测量不同光源在不同强度、距离和背景对比度下的吸引力、排斥力或飞行偏转。iii)反捕食者防御：捕食是许多物种死亡的主要原因，我们的模型表明，人造光源可能会削弱这种防御。采用背景选择实验和对照捕食实验相结合的方法，研究不同类型人工光源下夜间背景选择对视觉引导鸟类捕食风险的影响。实现这三个目标将首次评估新型光源对飞蛾（或任何动物）视觉生态的潜在影响。至关重要的是，通过确定特定类型的人造光如何以及为什么干扰关键行为和种间相互作用，我们将能够评估它们对授粉和飞蛾生存的可能影响，这将反过来影响野花和其他传粉者群体的生物多样性，从而影响粮食安全。此外，研究结果将有助于制定有针对性的缓解策略，从整个分类群水平一直到特定物种的相互作用。这是至关重要的，因为在我们的模型中被确定为可能破坏授粉行为的下一代光源已经被部署。

Artificial light at night, from streetlights and other sources, is increasing at unprecedented rates, in terms of intensity and worldwide coverage. This lighting almost certainly has wide-ranging effects on the visual ecology of nocturnal animals, and has been implicated in the dramatic population declines of nocturnal moths throughout Europe.Many nocturnal moths use their outstanding low-light colour vision to locate flowers at night and are major global contributors to pollen transport networks. Recent research has highlighted the potential for artificial light sources to interfere with the vision of nocturnal pollinators, change their abundance and distribution across landscapes, affect pollination quality, and alter their response to predators. Attraction to light sources is also a well known cause of mortality in many insects. Nevertheless, much of this research remains correlative, or limited to specific species, and a fundamental behavioural understanding is lacking of how different artificial light sources affect specific visual interactions that are key to the survival of moths and the plants they pollinate.Our visual modelling work identified unexpected interactions between light type, light intensity and object colour, for example allowing the same flower to change from highly conspicuous to a background-matching colour dependent on light intensity. Such effects could fundamentally disrupt pollinator behaviour in a manner that would be almost impossible to detect in the wild, and with unknown consequences for plants. Our modelling also suggested that artificial light could interfere with the anti-predator defences of moths by causing poor choices of background colour for daytime resting.This project will determine how nighttime artificial light affects three key aspects of moth visual ecology: i) Floral signalling: we will investigate the predictions of our visual modelling using semi-natural experiments, testing the effects of complex interactions between light type, light intensity and flower colour on visually-guided flower detection and handling behaviour. ii) Flight behaviour: tethered flight experiments using simulated viewing conditions will be used to determine how different moth species respond to different aspects of artificial light and background scene appearance, and which hypothesised orientation mechanisms are affected. Specifically, this will measure the attraction, repulsion or flight deflection of different light sources at different intensities, distances and background contrasts. iii) Anti-predator defences: predation is the main source of mortality in many species, and our modelling suggests that artificial light sources could weaken this defence. A combination of moth background choice experiments and controlled predation experiments will determine how nighttime background choice under different types of artificial light affects predation risk from visually-guided avian predators in the daytime.Fulfilling these three objectives will provide the first assessment of the potential impact of novel light sources on the visual ecology of moths (or any animal). Critically, by determining how and why specific types of artificial light interfere with key behaviours and interspecific interactions we will be able to assess their likely impact on pollination and moth survival, which will in turn affect the biodiversity of wildflowers and other pollinator groups, with implications for food security. Moreover, the results will facilitate the development of targeted mitigation strategies from whole-taxon levels, right down to species-specific interactions. This is critical because next-generation light sources identified as potentially disruptive to pollination behaviour in our modelling are already being deployed.