Time, Light & Sound: the effect of the urban environment on the movement ecology of owls

关键词：光污染，噪音，猫头鹰，GPS跟踪，城市化城市化是最普遍的栖息地变化形式之一。目前，世界上一半以上的人口居住在城市地区，城市土地覆盖面积预计将在2000年至2030年之间增加两倍。这对单一物种、生物多样性和生态系统服务构成了重大威胁(1)。然而，一些物种可能能够在城市地区扎根，与生活在自然栖息地的同类相比，它们通常表现出强烈的生理和行为变化。最终，这些城市人口的未来将取决于他们适应城市生活的能力。人们越来越认识到，城市化不仅可以深刻地改变空间环境，还可以深刻地改变时间环境。特别关键的是夜间的人造光和局部升高的声音水平，它们会影响自然节律环境，扰乱生物时钟，干扰感官知觉，并最终导致食物链上的相关变化（例如，猎物的行为）。然而，这样的证据主要来自昼行动物，它们被发现将活动扩展到夜间，以延长觅食时间，提高交配成功率，利用光污染的存在来观察和穿越城市的夜晚。相比之下，夜行动物的数据却令人惊讶地缺乏。夜行动物也可能受到夜间光线的强烈影响，尤其是在猎物想要避免被捕食者看到的情况下。此外，夜间捕食者经常使用声音线索进行捕猎，这也使它们容易受到人为噪音的影响。一方面，这些声音狩猎者可能被迫在夜间安静的时段觅食，例如避免在嘈杂的高峰时段活动。另一方面，它们可能会在感官线索之间切换，在嘈杂的地区更多地依靠视觉狩猎，甚至可能利用被人为光线污染的地区来寻找猎物。区分这些相互竞争的假设，尽管不是完全排斥的假设，将为物种如何适应人为的时间环境提供新颖而令人兴奋的见解。这个项目将通过研究茶色猫头鹰（Strix aluco）来解决这个独特的挑战，茶色猫头鹰是一种夜间捕食者，通常通过声音捕食。每只猫头鹰将被24小时跟踪，使用加速度计来详细记录行为，GPS来详细记录空间使用，以及声音计和亮度计来详细记录鸟类所经历的感官环境。同时，我们将量化这些猛禽移动时的光景和声景，通过全天候使用专用传感器对动物进行记录。我们将进一步从巢穴中收集有关供给率、交付食物和繁殖成功率的数据。具体来说，该项目有三个基本目标：-目标1：城市和森林栖息猫头鹰的活动时间：使用加速度测量数据量化茶色猫头鹰在时间上的可塑性。-目标2：穿越城市光景和声景：研究感官污染物（光和噪音）如何影响觅食行为和觅食效率。为此，我们将使用鸟类测量的光线和高分辨率GPS数据，以及地面测量的噪音。利用这些数据，我们将建立运动模型，以确定猫头鹰对时间结构的时空响应，人类对其栖息地的变化。-目标3：与饮食和生殖成功的联系：确定城市地区时间和空间利用的改变如何影响饮食和生殖成功。父母觅食效率降低，食物质量减少或降低，休息阶段中断都会影响雏鸟的身体状况和羽化成功。

Studentship strategic priority area: BiodiversityKeywords: Light pollution, noise, owls, GPS tracking, urbanisationUrbanisation is one of the most pervasive forms of habitat change. More than half of the world's human population now resides in urban areas, and urban land cover is projected to triple between 2000 and 2030. This poses major threats to single species, biodiversity and ecosystem services (1). Nevertheless, some species may be able to establish in urban areas, where they usually display strong physiological and behavioural changes compared to their counterparts living in natural habitats. Ultimately, the future of these urban populations will depend on their ability to adapt to city life.There is increasing recognition that urbanisation can profoundly modify not only the spatial environment, but also the temporal one. Particularly critical are artificial light at night and locally elevated sound levels, which can affect the natural rhythmic environment, disrupt organismal clocks, interfere with sensory perception, and ultimately lead to associated changes along the food chain (for example, behaviour of prey). However, such evidence comes mostly from diurnal species, which have been found to expand their activity into the night to extend foraging time and increase mating success, exploiting the presence of light pollution to see and move through the urban night. In contrast, there is a surprising lack of data from nocturnal species. Nocturnal species may also be strongly affected by light at night, especially in the case of prey that want to avoid being seen by predators. Moreover, nocturnal predators often hunt using acoustic cues, which makes them susceptible to anthropogenic noise, too. On one hand, these acoustic hunters may be forced to forage during quieter periods of the night, for instance by avoiding activity at noisy rush hours. On the other hand, they might switch between sensory cues and rely more on visual hunting in noisy areas, perhaps even exploiting areas polluted by anthropogenic light to find their prey. Distinguishing between these competing, although not fully exclusive hypotheses, will provide novel and exciting insights into how species may adapt to anthropogenic temporal environments.This project will approach this unique challenge by studying Tawny owls (Strix aluco), a nocturnal predator that usually prey by sound. Individual owls will be tracked around-the-clock, using accelerometers to detail behaviour, GPS to detail space use, and soundmeters and lightmeters to detail the sensory environments experienced by the birds. Simultaneously, we will quantify the lightscapes and soundscapes in which these raptors move, by around-the-clock, on-animal recordings using dedicated sensors. We will further collect data from nests about provisioning rates, delivered food items, and breeding success. Specifically, this project has three fundamental objectives:- Objective 1: Timing of activities in city- and forest-dwelling owls: To quantify the plasticity in timing of Tawny owls using accelerometry data.- Objective 2: Moving through urban lightscapes and soundscapes: To examine how sensory pollutants (light and noise) shape foraging behaviour and foraging efficiency. To this end we will use on-bird measures of light and high-resolution GPS data, and from ground measurements of noise. Using these data, we will build movement models to identify spatio-temporal responses of owls to time-structured, anthropogenic changes to their habitats.- Objective 3: Links to diet and reproductive success: To identify how the modified use of time and space in urban areas impacts on diet and reproductive success. Decreased parental foraging efficiency, delivery of fewer or lower quality food items, and disrupted rest phases could all impact nestlings' body condition and fledging success.