Over the last 150 years the natural nighttime environment has been drastically altered by the proliferation of artificial light. The amount of artificial light at night is on the increase, and there is a current trend to replace older lighting with more energy efficient types such as light emitting diodes (LEDs) or ceramic metal halide; in Cornwall, UK, there has been a relatively recent replacement of the street lighting, from low pressure sodium to ceramic metal halide. Alongside the increasing amount of artificial nighttime light, recent research has highlighted declines in macro moth numbers. Given the well-known ‘flight-to-light’ behaviour of moths, and the negative effects this behaviour can have, alongside other known and potential ways in which nighttime light can affect moths, the increasing amount of artificial light in the environment is a suspected contributor to the declines. It is particularly important to understand how modern lighting technologies will impact upon moths, as different spectra of light are known to vary in terms of how attractive they are. As a means to determine the potential impact of different street lighting types on moths, particularly the ceramic metal halide lighting rolled out in Cornwall, UK, we compared the attractiveness to macro moths, of a number of increasingly used, energy efficient, street lighting types. We found that shorter wavelength metal halide lighting attracted significantly more individuals and species of moth than longer wavelength high pressure sodium lighting. In a second experiment, we also found ceramic metal halide lighting to be more attractive to macro moths than LED lighting. Reduced emissions of short wavelength UV light was deemed the likely reason behind the fewer macro moths attracted to the high pressure sodium and LED lighting. Interestingly, we also found striking differences in the relative attractiveness of the different lighting types to different moth groups. The metal halide lighting attracted significantly more Noctuidae than high pressure sodium lighting, whereas both high pressure sodium and metal halide lighting were equally attractive to Geometridae. Understanding accurately the extent to which different groups of moth are attracted to different wavelengths of light could be useful in determining the impact of artificial light on moth populations. In addition to impacting moths through attraction, artificial light has the potential to alter the day length as perceived by organisms, which at mid- to high latitudes is utilised by certain species as an abiotic cue to ensure the coincidence of development with favourable environmental conditions. Due to a paucity of knowledge on how raised ambient nighttime light levels affect moths and the trophic levels with which they interact, we carried out analyses into the impact of nighttime light on the winter moth and its host plant oak; a well-studied model system, where synchrony between moth egg hatch and oak budburst is important for the moth’s survival. Firstly we carried out an analysis looking at the relationship between the amount of nighttime light and the date of oak budburst. Spatially referenced budburst dates were matched with satellite imagery of nighttime lighting and average spring temperature data, and the relationship between the variables was analysed. Model predictions suggested that oak budburst occurs earlier in brighter areas. In addition, the predicted advance of budburst in brighter areas was still apparent when analysing only the data points that fell outside of large urban areas, where the urban heat island effect is likely reduced. The findings suggested that artificial nighttime light may be causing an advance in oak budburst. To follow up the spatial analysis we carried out a field experiment. We used light cages that simulated various nighttime lighting scenarios to test whether oak budburst and winter moth egg hatch were affected by low intensity light at night. In contrast to the spatial analysis, there was no significant relationship found between light treatment and the phenology of either oak budburst or winter moth egg hatch. However, there was a suggestion in the data that the higher buds of the oak saplings emerged earlier in the yellow light treatment, highlighting the need for further research into the potential impact of artificial nighttime light on phenology and species interactions. In conclusion, the findings of this research project provide information useful to those seeking ecologically sensitive lighting solutions, and also highlight a potential tool to assist in determining whether light at night is a causative factor behind apparent moth declines. In addition, they suggest that artificial light at night may be affecting the phenology of an ecological system at a national scale. Finally, this research project has highlighted the complexity of the ecological impacts of artificial light at night, and also a need for further research.

Master of Science / Department of Architectural Engineering and Construction Science / Fred L. Hasler / This paper discusses photopic and scotopic vision of the human eye and the implications that could result in the design process of the lighting industry. The incorporation of scotopic vision in lighting effects the perceived illumination in all settings; but these affects and benefits are seen more prevalently at night, as this is when scotopic vision is utilized by the eye the most. The paper will begin with an overview of the eye including discussions of exactly what photopic and scotopic vision are, as well as how the eye works. This will lay a foundation for the paper to help the reader better comprehend and understand the remainder of the content. After the groundwork has been laid, the factors that affect how the eye perceives light will be discussed. These factors include pupil size and color of the light. A discussion of the basis for current lighting industry design and how light levels are measured will follow. Once these topics have been fully explored, there will be a discussion of the changes that could occur in the lighting industry if scotopic vision is taken into account. Increased energy efficiency would result if the scotopic vision is incorporated, resulting from the decrease in needed total lumen output. There have been a few applications that have utilized the effects of the scotopic vision in their design, these cases will be presented. Following the case study discussions, will be a discussion of a survey conducted by myself on the change-out of high pressure sodium (HPS) fixtures to LED fixtures in the downtown Poyntz Avenue area of Manhattan, KS. After all studies have been reviewed, conclusions and correlations among them will be explored. Following this analysis, suggestions will be given to improve the way lighting is designed in the industry.

The greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern that has undergone serious declines in the last century. The Strawberry Valley sage grouse population in Utah underwent such a decline from an estimated 3,500 sage grouse in the 1930s to 150 sage grouse in the early 2000s. This decline initiated a long-term conservation and monitoring project in Strawberry Valley with the goal of preserving the sage grouse population. As part of this ongoing conservation project, we investigated factors that impact the success of capturing sage grouse using the night-lighting method (Chapter 1). We found that capture success is influenced by precipitation, frost, vegetation, flock size, capture crew size, mode of transportation, and sex of the sage grouse. We provide information on these influential factors as well as recommendations on equipment and technique. We also compiled a dataset beginning in the 1930s of sage grouse clutch sizes from the Strawberry Valley population to determine the average number of eggs per clutch (Chapter 2). We investigated average clutch size over time, factors that influence average clutch size, and the accuracy and reliability of our clutch size counts. We found yearly variation in average clutch size that shows a weak, positive correlation with population size. Clutch sizes were smaller if laid as a re-nest or by sage grouse recently translocated from a different population. We found evidence that some of our clutch size counts are approximately two eggs fewer than the actual number laid by the sage grouse.

As human population grows and develops, more urban areas are expanding. Urbanisation has many impacts on the natural environment and one understudied pollutant is artificial light at night. The aims of this thesis were to examine the impacts of street lighting on bats and investigate the exposure of British bat species to artificial light at night and explored the mitigation option of part-night lighting. The current exposure of British bat species to artificial lighting was assessed using roost locations and population sizes from a long-term dataset (1997-2012) from the Bat Conservation Trust’s National Bat Monitoring Programme on seven bat species (Eptesicus serotinus, Myotis nattereri, Pipistrellus pipistrellus, P. pygmaeus, Plecotus auritus, Rhinolophus hipposideros and R. ferrumequinum). These data were combined with satellite imagery in roost sustenance zones and home ranges. Bat roosts were found in areas with brighter light levels than random locations for P. pipistrellus, P. pygmaeus and Plecotus auritus. Species that forage around streetlights (P. pipistrellus and P. pygmaeus) had significantly higher light levels in the landscape around their roosts than species which avoid street lit areas (R. hipposideros, M. nattereri and P. auritus). Colony size was negatively correlated with light levels. This study highlights that different species have different requirements in the landscapes around their roosts. To investigate landscapes effects of artificial light at night on the understudied light avoiding species R. ferrumequinum, eight maternity roosts were surveyed to explore the interaction between habitat features and street lighting. At each maternity roost, bat detectors were deployed at 25 paired street lit and dark locations. Street lighting had a significant negative effect on bat activity. Locations closest to the maternity roost had higher bat activity than those further away and road type had a significant effect on bat activity, with the highest bat activity recorded at minor roads compared with A and B roads. These results highlight the large negative impact street lighting can have on bat activity patterns and the need for mitigation. Several mitigation strategies have been suggested to combat the effects of artificial light at night but few have been tested. One of these suggestions is to restrict the hours of lighting through the night, often called part-night lighting. Part-night lighting has been implemented by many local authorities, often switching the lights off after midnight and switching them back on before dusk. To explore the effects of part night lighting on bats, the hourly patterns of activity for R. ferrumequinum were studied. Bat activity was bimodal, with a peak in the first few hours after sunset followed by a smaller peak before sunrise. To capture more than 50% of bat activity during the dark period of the night, street lights would be required to switch off before 11pm. To explore this further, a before-and-after study of part-night lighting was conducted at towns across Devon. Following the conversion from full-night lighting to part-night lighting, switching street lights off at 2 am, there was a significant reduction in P. pipistrellus and a significant increase for P. pygmaeus and Nyctalus noctule activity. Although part-night lighting is not often operational during peak activity periods for bat species, reducing the duration of lighting at night has impacts on activity patterns for several species. This thesis shows that artificial light at night has impacts on bats across the landscapes around their roosts. Artificial lighting has impacts for species in different ways, depending on whether they forage around street lights or avoid street lit areas. For species that avoid street lit areas such as R. ferrumequinum, street lighting can have very significant negative impacts on the availability of areas around their roosts. This highlights the need for conservation measures to reduce impacts of artificial lighting. Although mitigation schemes such as part-night lighting may help to minimize impacts of nighttime lighting, more tailored schemes for bats should devised to achieve greater conservation impacts.