Clinton David Francis

• PhD - University of Colorado
• Professor (Assistant) at California Polytechnic State University

As human development has expanded, so has the prevalence of anthropogenic noise, which can interfere with acoustic channels used by wildlife. However, since landscapes contain natural sources of persistent noise from features such as rivers, animals may be preadapted to cope with novel human‐generated noise. Comparing how animals respond to anthrop...

Aim The goal of this work was to investigate whether the community of avian nest predators shifts from nocturnal to diurnal with changes in latitude. This hypothesis was formulated 70 years ago, under the rationale that longer day length during the bird breeding season at high latitudes increases opportunities for visual predators. Based on other s...

Sensory environments are rapidly changing due to increased human activity in urban and non-urban areas alike. For instance, natural and anthropogenic sounds can interfere with parent-offspring communication and mask cues reflective of predation risk, resulting in elevated vigilance at the cost of provisioning. Here we present data from two separate...

Environmental noise knows no boundaries, affecting even protected areas. Noise pollution, originating from both external and internal sources, imposes costs on these areas. It is associated with adverse health effects, while natural sounds contribute to cognitive and emotional improvements as ecosystem services. When it comes to parks, individual v...

The way in which terrestrial organisms use the acoustic realm is fundamentally important and shapes behavior, populations, and communities, but how background acoustics, or noise, influence the patterns and processes in ecology is still relatively understudied. In this review, we summarize how background acoustics have traditionally been studied fr...

Anthropogenic noise and its effects on acoustic communication have received considerable attention in recent decades. Yet, the natural acoustic environment’s influence on communication and its role in shaping acoustic signals remains unclear. We used large-scale playbacks of ocean surf in coastal areas and whitewater river noise in riparian areas t...

Traffic noise is one of the leading causes of reductions in animal abundances near roads. Acoustic masking of conspecific signals and adventitious cues is one mechanism that likely causes animals to abandon loud areas. However, masking effects can be difficult to document in situ and the effects of infrequent noise events may be impractical to stud...

The broken-wing display is a well-known and conspicuous deceptive signal used to protect birds' broods against diurnal terrestrial predators. Although commonly associated with shorebirds, it remains unknown how common the behaviour is across birds and what forces are associated with the evolution of the display. Here, we use the broken-wing display...

Animals glean information about risk from their habitat. The acoustic environment is one such source of information, and is an important, yet understudied ecological axis. Although anthropogenic noise has become recently ubiquitous, risk mitigation behaviors have likely been shaped by natural noise over millennia. Listening animals have been shown...

Anthropogenic noise has received considerable recent attention, but we know little about the role that sources of natural noise have on wildlife abundance and distributions. Rivers and streams represent an ancient source of natural noise that is widespread and covers much of Earth. We sought to understand the role that whitewater river noise plays...

Supplemental file for paper "Experimental river noise alters arthropod abundance" published in Oikos at https://doi.org/10.1111/oik.08499. See data and code upload here: https://doi.org/10.5281/zenodo.4563734

A major challenge for studies assessing drivers of phenotypic divergence is the statistical comparison of taxa with unique, often unknown, evolutionary histories, and for which there are no clear expected trait values. Because many traits are fundamentally constrained by energy availability, we suggest that trait values predicted by scaling theorie...

Light and noise pollution from human activity are increasing at a dramatic rate. These sensory stimuli can have a wide range of effects on animal behavior, reproductive success, and physiology. However, less is known about the functional and community-level consequences of these sensory pollutants, especially when they co-occur. Using camera traps...

Synopsis Global expansion of lighting and noise pollution alters how animals receive and interpret environmental cues. However, we lack a cross-taxon understanding of how animal traits influence species vulnerability to this growing phenomenon. This knowledge is needed to improve the design and implementation of policies that mitigate or reduce sen...

Synopsis Light pollution, or the presence of artificial light at night (ALAN), is among the fastest growing but least understood anthropogenic stressor on the planet. While historically light pollution has not received attention comparable to climate change or chemical pollution, research over the past several decades has revealed the plethora of n...

Recent research suggests that anthropogenic noise can substantially alter animal behavior. Although there are many sources of natural background noise, the relative influence of these sounds on behavior has received much less attention. Using landscape-scale playbacks of rushing rivers and crashing ocean surf, we investigated how habitat appropriat...

The extent of artificial night light and anthropogenic noise (i.e., “light” and “noise”) impacts is global and has the capacity to threaten species across diverse ecosystems. Existing research involving impacts of light or noise has primarily focused on noise or light alone and single species; however, these stimuli often co-occur and little is kno...

Protected natural areas are not free from noise, especially noise generated by traffic within park boundaries. Natural soundscapes are important for maintaining community structure, providing positive visitor experiences, and increasing visitor support for management actions that reduce impacts on natural resources. To test experimental quieting as...

Natural sensory environments, despite strong potential for structuring systems, have been neglected in ecological theory. Here, we test the hypothesis that intense natural acoustic environments shape animal distributions and behavior by broadcasting whitewater river noise in montane riparian zones for two summers. Additionally, we use spectrally-al...

Noise pollution can affect species' behaviours and distributions and may hold significant consequences for natural communities. While several studies have researched short-term effects of noise, no long-term research has examined whether observed patterns persist or if community recovery can occur. We used a long-term study system in New Mexico to...

Emerging infectious diseases (EIDs) present global health threats, and their emergences are often linked to anthropogenic change. Artificial light at night (ALAN) is one form of anthropogenic change that spans beyond urban boundaries and may be relevant to EIDs through its influence on the behaviour and physiology of hosts and/or vectors. Although...

Artificial light at night (ALAN) functions as a novel environmental stimulus that has the potential to disrupt interactions among species. Despite recent efforts to explain nocturnal pollinators' responses to this stimulus, the likelihood and associated mechanisms of attraction towards artificial light and potential consequences on fitness for diur...

Anthropogenic noise and artificial night lighting have been shown to have substantial effects on animal behavior, physiology, and species interactions. Despite the large body of previous work, very few studies have studied the combined effects of light and noise pollution, especially experimentally in the field. Rodents are a highly diverse group t...

Global expansion of lighting and noise pollution alters how animals receive and interpret environmental cues. Yet we lack a cross-taxon understanding of how animal traits influence species vulnerability to this growing phenomenon. This knowledge is needed to improve the design and implementation of policies that mitigate or reduce sensory pollutant...

Anthropogenic noise has received significant attention in recent years, and researchers have highlighted the ways in which animals might deal with these noise sources. However, much of our understanding of animal responses to this novel source of background acoustics lacks an evolutionary perspective. Natural sources of noise predate the origin of...

Spending time in nature is known to benefit human health and well-being, but evidence is mixed as to whether biodiversity or perceptions of biodiver- sity contribute to these benefits. Perhaps more importantly, little is known about the sensory modalities by which humans perceive biodiversity and obtain benefits from their interactions with nature....

Expansion of anthropogenic noise and night lighting across our planet1,2 is of increasing conservation concern3–6. Despite growing knowledge of physiological and behavioural responses to these stimuli from single-species and local-scale studies, whether these pollutants affect fitness is less clear, as is how and why species vary in their sensitivi...

Burgeoning urbanization, development and human activities have led to reduced opportunities for nature experience in quiet acoustic environments. Increasing noise affects both humans and wildlife alike. We experimentally altered human‐caused sound levels in a paired study using informational signs that encouraged quiet behaviours in week‐on, week‐o...

Artificial nightlight is increasingly recognized as an important environmental disturbance that influences the habitats and fitness of numerous species. However, its effects on wide‐ranging vertebrates and their interactions remain unclear. Light pollution has the potential to amplify land‐use change, and as such, answering the question of how this...

Experimental inquiry-oriented science labs can be designed to have students regulate their own learning and decide when they leave class or to have the teacher regulate student learning and determine when they leave class. In this study, grades were examined relative to student exit times in a student-regulated class design. Preliminary interviews...

Sensory pollutants such as anthropogenic noise and night lighting now expose much of the world to evolutionarily novel sound and night lighting conditions. An emerging body of literature has reported a variety of deleterious effects caused by these stimuli, spanning behavioral, physiological, population, and community-level responses. However, the...

Emerging infectious diseases (EIDs), including zoonotic arboviruses, present a global health threat. Multiple components of human land use change have been linked to arboviral emergence, but one pervasive factor that has received comparatively little attention is light pollution. Although often considered a component of built environments, artifici...

Noise pollution is pervasive across every ecosystem on Earth. Although decades of research have documented a variety of negative impacts of noise to organisms, key gaps remain, such as how noise affects different taxa within a biological community and how effects of noise propagate across space. We experimentally applied traffic noise pollution to...

Global expansion of human activities is associated with the introduction of novel stimuli, such as anthropogenic noise, artificial lights and chemical agents. Progress in documenting the ecological effects of sensory pollutants is weakened by sparse knowledge of the mechanisms underlying these effects. This severely limits our capacity to devise mi...

Rates of human-induced environmental change continue increasing with human population size, potentially altering animal physiology and negatively affecting wildlife. Researchers often use glucocorticoid concentrations (hormones that can be associated with stressors) to gauge the impact of anthropogenic factors (e.g. urbanization, noise and light po...

The soundscape serves as a backdrop for acoustic signals dispatched within and among species, spanning mate attraction to parasite host detection. Elevated background sound levels from human-made and natural sources may interfere with the reception of acoustic signals and alter species interactions and whole ecological communities. We investigated...

Many animals rely on the acoustic environment for functions spanning mate attraction, navigation and predator and prey detection. Growing evidence focused on human-altered acoustic environments suggests that anthropogenic noise can strongly interfere with the reception of biologically relevant sounds, causing a variety of behavioural changes in res...

Reductions in animal body size over recent decades are often interpreted as an adaptive evolutionary response to climate warming. However, for reductions in size to reflect adaptive evolution, directional selection on body size within populations must have become negative, or where already negative, to have become more so, as temperatures increased...

Glucocorticoid (GC) hormones are important phenotypic mediators across vertebrates, but their circulating concentrations can vary markedly. Here we investigate macroevolutionary patterning in GC levels across tetrapods by testing seven specific hypotheses about GC variation and evaluating whether the supported hypotheses reveal consistent patterns...

Circulating glucocorticoids (GCs) are the most commonly used biomarker of stress in wildlife. However, their utility as a tool for identifying and/or managing at-risk species has varied. Here, we took a very broad approach to conservation physiology, asking whether IUCN (International Union for the Conservation of Nature) listing status (concern ve...

At macroevolutionary scales, stress physiology may have consequences for species diversification and subspecies richness. Populations that exploit new resources or undergo range expansion should cope with new environmental challenges, which could favour higher mean stress responses. Within-species variation in the stress response may also play a ro...

Artificial nest boxes are critical nesting sites for secondary cavity-nesting birds; however, they are often placed near roadways and in urban areas that experience noise pollution and other human-caused stressors. Recent correlative studies document both negative and positive influences of noise pollution on reproductive success. Additionally, obs...

Glucocorticoids are stress hormones that can strongly influence physiology, behavior and an organism's ability to cope with environmental change. Despite their importance, and the wealth of studies that have sought to understand how and why glucocorticoid (GC) concentrations vary within species, we do not have a clear understanding of how circulati...

Animals go through different life history stages such as reproduction, moult, or migration, of which some are more energy-demanding than others. Baseline concentrations of glucocorticoid hormones increase during moderate, predictable challenges and thus are expected to be higher when seasonal energy demands increase, such as during reproduction. By...

Synopsis: To address large-scale questions in evolutionary biology, the compilation of data from a variety of sources is often required. This is a major challenge in the development of databases in organismal biology. Here, we describe the procedure we used to reconstruct the phylogeny of the 474 species represented in HormoneBase, including fish,...

Hormones are central regulators of organismal function and flexibility that mediate a diversity of phenotypic traits from early development through senescence. Yet despite these important roles, basic questions about how and why hormone systems vary within and across species remain unanswered. Here we describe HormoneBase, a database of circulating...

Anthropogenic noise is widespread, and growing evidence suggests that it can negatively affect animals through many different mechanisms including masking of cues and signals, distraction, and aversion to noise. Acoustic masking has received the most attention from researchers and recent evidence suggests that masking effects can be mitigated by al...

Anthropogenic noise is more intense at lower sound frequencies, which could decrease urban tolerance of animals with low-frequency vocalizations. Four large comparative studies tested whether anthropogenic noise filters bird species according to the sound frequencies they use and produced discrepant results. We reanalysed data from these studies to...

The comment by Myers-Smith and Myers focuses on three main points: (i) the lack of a mechanistic explanation for climate-selection relationships, (ii) the appropriateness of the climate data used in our analysis, and (iii) our focus on estimating climate-selection relationships across (rather than within) taxonomic groups. We address these critique...

Significance Studies examining relationships among habitat disturbance, physiology, and fitness in wild animals often produce contradictory or inconclusive results, casting doubt on current conservation physiology predictive frameworks linking stress and fitness. We apply a new framework drawn from experimental systems utilizing chronic inescapable...

Protected areas are critical locations worldwide for biodiversity preservation and offer important opportunities for increasingly urbanized humans to experience nature. However, biodiversity preservation and visitor access are often at odds and creative solutions are needed to safeguard protected area natural resources in the face of high visitor u...

Characteristics of buildings and land cover surrounding buildings influence the number of bird-window collisions, yet little is known about whether bird-window collisions are associated with urbanization at large spatial scales. We initiated a continent-wide study in North America to assess how bird-window collision mortality is influenced by build...

Throughout the world, birds represent the primary type of wildlife that people experience on a daily basis. However, a growing body of evidence suggests that alterations to the acoustic environment can negatively affect birds as well as humans in a variety of ways, and altered acoustics from noise pollution has the potential to influence human inte...

Climate-driven selection Climate change will fundamentally alter many aspects of the natural world. To understand how species may adapt to this change, we must understand which aspects of the changing climate exert the most powerful selective forces. Siepielski et al. looked at studies of selection across species and regions and found that, across...

Climate change has the potential to affect the ecology and evolution of every species on Earth. Although the ecological consequences of climate change are increasingly well documented, the effects of climate on the key evolutionary process driving adaptation - natural selection - are largely unknown. We report that aspects of precipitation and pote...

Anthropogenic noise is a widespread and growing form of sensory pollution associated with the expansion of human infrastructure. One specific source of constant and intense noise is that produced by compressors used for the extraction and transportation of natural gas. Terrestrial arthropods play a central role in many ecosystems, and given that nu...

A growing body of evidence suggests that traffic noise negatively affects wildlife. Protected natural areas are not free from noise exposure, both external to and within park boundaries. Natural soundscapes are important in many aspects of animal life histories, for increasing positive visitor experiences, and for providing psychological ecosystem...

Climate change is expected to increase climate variability and the occurrence of extreme climatic events, with potentially devastating effects on aquatic ecosystems. However, little is known about the role of climate extremes in structuring aquatic communities or the interplay between climate and local abiotic and biotic factors. Here, we examine t...

Anthropogenic noise has been increasing globally. Laboratory experiments suggest that noise disrupts foraging behavior across a range of species, but to reveal the full impacts of noise, we must examine the impacts of noise on foraging behavior among species in the wild. Owls are widespread nocturnal top predators and use prey rustling sounds for l...

Noise pollution degrades natural acoustic conditions, potentially interfering with bird communication. However, exactly how noise impacts the ability of the signal receiver to detect and discriminate vocalizations from conspecifics remains understudied in field settings. We performed a natural experiment to determine the effect of noise pollution o...

Anthropogenic noise is a pervasive and chronic source of disturbance, posing many challenges for a variety of taxa. Bats are acoustic predators, making their foraging vulnerable to a louder soundscape. Pallid bats rely on low frequency prey-produced sounds to hunt and are exposed to numerous sources of noise pollution, including sounds produced by...

Human activities have caused a near-ubiquitous and evolutionarily-unprecedented increase in environmental sound levels and artificial night lighting. These stimuli reorganize communities by interfering with species- specific perception of time-cues, habitat features, and auditory and visual signals. Rapid evolutionary changes could occur in respons...

The acoustic environment and natural cycle of day and night are of fundamental importance to countless species. Yet two prominent and underappreciated features of anthropogenic environmental change, noise and artificial light, are creating acoustic condition and light regimes that are highly novel across the globe. These stimuli can compromise the...

Global population growth has caused extensive human-induced environmental change, including a near-ubiquitous transformation of the acoustical environment due to the propagation of anthropogenic noise. Because the acoustical environment is a critical ecological dimension for countless species to obtain, interpret and respond to environmental cues,...

Abstract Background: Commonplace biodiversity labs in introductory undergraduate biology typically emphasize declarative knowledge. We contend that shifting these labs to emphasize evolution, higher-order cognition, and science reasoning would benefit student learning. Four factors that likely make evolution-based higher-order learning goals diffic...

We examined the effects of documenting observations with digital imaging versus hand drawing in inquiry-based college biodiversity labs. Plant biodiversity labs were divided into two treatments, digital imaging (N = 221) and hand drawing (N = 238). Graduate-student teaching assistants (N = 24) taught one class in each treatment. Assessments reveale...

Negative impacts from anthropogenic noise are well documented for many wildlife taxa. Investigations of the effects of noise on bats however, have not been conducted outside of the laboratory. Bats that hunt arthropods rely on auditory information to forage. Part of this acoustic information can fall within the spectrum of anthropogenic noise, whic...

We examined how different styles of written feedback by graduate-student teaching assistants (GTAs) in college intro biology lab (USA) influenced student achievement and related the different styles to time efficiency. We quantified GTA feedback on formative lab reports and student achievement on two different types of assessments, a quiz in 2010 a...

We compared learning cycle and expository formats for teaching about plant biodiversity in an inquiry-oriented university biology lab class (n = 465). Both formats had preparatory lab activities, a hands-on lab, and a postlab with reflection and argumentation. Learning was assessed with a lab report, a practical quiz in lab, and a multiple-choice e...

The world is a noisy place, but the global rise of anthropogenic noise radiating from our cities and dendritic transportation networks has created acoustical conditions that are bad for people (Alberti 1998; Babisch 2003; Jarup et al. 2008) and can present novel environmental challenges for wild organisms. Biologists have recently begun to unveil h...

Misinterpretations of entropy and conflation with additional misunderstandings of the second law of thermodynamics are ubiquitous among scientists and non-scientists alike and have been used by creationists as the basis of unfounded arguments against evolutionary theory. Entropy is not disorder or chaos or complexity or progress towards those state...

Anthropogenic noise is an important environmental stressor that is rapidly gaining attention among biologists, resource managers, and policy makers. Here we review a substantial literature detailing the impacts of noise on wildlife and provide a conceptual framework to guide future research. We discuss how several likely impacts of noise exposure h...

The island rule, a pattern of size shifts on islands, is an oft-cited but little understood phenomenon of evolutionary biology. Here, we explore the evolutionary mechanisms behind the rule in 184 mammal species, testing climatic, ecological and phylogenetic hypotheses in a robust quantitative framework. Our findings confirm the importance of specie...

Background/Question/Methods Many vertebrate populations are in decline as a result of human-induced environmental change, raising concerns that the ecological services they provide, such as seed dispersal and pollination, may be compromised, triggering further losses of biodiversity. One novel, yet widespread environmental change that has only re...

Background/Question/Methods Anthropogenic noise is inescapable in our world. From airplanes and cars to gas wells and wind turbines the acoustic byproducts of industrialized society are here to stay. Although humans tend to drown out or even ignore industrial background noise, the effects on other species are intriguing. The culmination of these...

Among songbirds, growing evidence suggests that acoustic adaptation of song traits occurs in response to habitat features. Despite extensive study, most research supporting acoustic adaptation has only considered acoustic traits averaged for species or populations, overlooking intraindividual variation of song traits, which may facilitate effective...

Increases in anthropogenic noise (hereafter “noise”) exposure may negatively affect reproductive success for breeding birds because noise may mask sounds of approaching predators. However, we recently found that increases in noise amplitude positively influenced nest survival through a decrease in nest predation. On the basis of this result, we hyp...

Several urban-adapted species sing at a higher frequency in noisy urban areas than in quiet locations. Yet it remains unclear whether the ability to adjust signals in response to noise is related to an ability to persist in noisy areas, because signal change and habitat use are infrequently measured within a single study. We investigated occupancy...

We used three site types to address whether noise from gas well compressors interfered with our ability to detect birds in the Rattlesnake Canyon Habitat Management Area, San Juan County, New Mexico: (1) gas wells without compressors (control), (2) gas wells with compressors turned off only during surveys (T-off), and (3) gas wells with compressors...

Noise pollution is a novel, widespread environmental force that has recently been shown to alter the behaviour and distribution of birds and other vertebrates, yet whether noise has cumulative, community-level consequences by changing critical ecological services is unknown. Herein, we examined the effects of noise pollution on pollination and seed...