Behavioral responses to predatory sounds predict sensitivity of cetaceans to anthropogenic noise within a soundscape of fear

Funding was provided by the US Navy Living Marine Resources and Office of Naval Research programs, Netherlands Ministry of Defence, Norwegian Ministry of Defence, UK Defence Science and Technology Laboratory, and DGA French Ministry of Defence.Acoustic signals travel efficiently in the marine environment, allowing soniferous predators and prey to eavesdrop on each other. Our results with four cetacean species indicate that they use acoustic information to assess predation risk and have evolved mechanisms to reduce predation risk by ceasing foraging. Species that more readily gave up foraging in response to predatory sounds of killer whales also decreased foraging more during 1- to 4-kHz sonar exposures, indicating that species exhibiting costly antipredator responses also have stronger behavioral reactions to anthropogenic noise. This advance in our understanding of the drivers of disturbance helps us to predict what species and habitats are likely to be most severely impacted by underwater noise pollution in oceans undergoing increasing anthropogenic activities. As human activities impact virtually every animal habitat on the planet, identifying species at-risk from disturbance is a priority. Cetaceans are an example taxon where responsiveness to anthropogenic noise can be severe but highly species and context specific, with source–receiver characteristics such as hearing sensitivity only partially explaining this variability. Here, we predicted that ecoevolutionary factors that increase species responsiveness to predation risk also increase responsiveness to anthropogenic noise. We found that reductions in intense-foraging time during exposure to 1- to 4-kHz naval sonar and predatory killer whale sounds were highly correlated (r = 0.92) across four cetacean species. Northern bottlenose whales ceased foraging completely during killer whale and sonar exposures, followed by humpback, long-finned pilot, and sperm whales, which reduced intense foraging by 48 to 97level responses to killer whale playbacks, implying a similar level of perceived risk. The correlation cannot be solely explained by hearing sensitivity, indicating that species- and context-specific antipredator adaptations also shape cetacean responses to human-made noise. Species that are more responsive to predator presence are predicted to be more disturbance sensitive, implying a looming double whammy for Arctic cetaceans facing increased anthropogenic and predator activity with reduced ice cover.Publisher PDFPeer reviewe

Amergent Music: behavior and becoming in technoetic & media arts

Merged with duplicate records 10026.1/1082 and 10026.1/2612 on 15.02.2017 by CS (TIS)Technoetic and media arts are environments of mediated interaction and emergence, where meaning is negotiated by individuals through a personal examination and experience—or becoming—within the mediated space. This thesis examines these environments from a musical perspective and considers how sound functions as an analog to this becoming. Five distinct, original musical works explore the possibilities as to how the emergent dynamics of mediated, interactive exchange can be leveraged towards the construction of musical sound. In the context of this research, becoming can be understood relative to Henri Bergson’s description of the appearance of reality—something that is making or unmaking but is never made. Music conceived of a linear model is essentially fixed in time. It is unable to recognize or respond to the becoming of interactive exchange, which is marked by frequent and unpredictable transformation. This research abandons linear musical approaches and looks to generative music as a way to reconcile the dynamics of mediated interaction with a musical listening experience. The specifics of this relationship are conceptualized in the structaural coupling model, which borrows from Maturana & Varela’s “structural coupling.” The person interacting and the generative musical system are compared to autopoietic unities, with each responding to mutual perturbations while maintaining independence and autonomy. Musical autonomy is sustained through generative techniques and organized within a psychogeographical framework. In the way that cities invite use and communicate boundaries, the individual sounds of a musical work create an aural context that is legible to the listener, rendering the consequences or implications of any choice audible. This arrangement of sound, as it relates to human presence in a technoetic environment, challenges many existing assumptions, including the idea “the sound changes.” Change can be viewed as a movement predicated by behavior. Amergent music is brought forth through kinds of change or sonic movement more robustly explored as a dimension of musical behavior. Listeners hear change, but it is the result of behavior that arises from within an autonomous musical system relative to the perturbations sensed within its environment. Amergence propagates through the effects of emergent dynamics coupled to the affective experience of continuous sonic transformation.Rutland Port Authoritie

Listening in on the forest: use of bioacoustics to preserve soundscapes and rare species

Effective monitoring and protection of tropical ecosystems has the potential to conserve vast amounts of the earth’s biodiversity. Yet logistical and technical challenges associated with species rarity, large distributions and home ranges, low detectability and inaccessibility of study sites can hinder monitoring efforts. If we are to mitigate against the threats to biodiversity and restore natural ecosystems, then we urgently need rapid and cost-effective methods to evaluate the current state of species, communities, ecosystems and the effectiveness of interventions. Here, we use passive acoustic monitoring (PAM) combined with computational approaches, as a method to effectively measure trends in biodiversity at a wide spatial scale across a biodiverse region in the tropics. In Chapter Two we used soundscape analysis to evaluate changes in acoustic diversity across the diel cycle over a gradient of land use change. We aimed to assess if soundscape indices can reveal changes in the biological community across the diel cycle and whether loss of native forests affect acoustic diversity in tropical ecosystems. In disturbed habitats, we found a loss of the characteristic dawn and dusk peaks in the diel cycle; known as the dawn and dusk chorus. This was especially prominent in palm oil plantations and grasslands, which showed a complete loss of these peaks. This suggests that in disturbed ecosystems there is likely a loss of species diversity, a shift in species composition, where forest specialists are being replaced by disturbance tolerant species, or that there are modifications in species behaviour, reinforcing the value of native old growth forests in maintaining ecosystem functionality. This loss in dawn and dusk peaks was not apparent when analysing acoustic diversity at specific times during the diel cycle, showing that evaluating acoustic diversity at this temporal scale can be misleading, but in assessing trends across the diel cycle, we can gain a much better representation of changes to biotic communities. In Chapter Three we determined if PAM and a newly developed automated detection and classification system was effective at retrieving information on the Geoffroy’s spider monkey at a wide spatial scale. We assessed how this endangered primate responds to habitat loss and human influence across a gradient of disturbance. We found that the Geoffroy’s spider monkey was absent below 80% forest cover and within 1 km of paved roads, yet was found to some extent in areas of secondary forest and near unpaved roads and buildings. The success of this methodology in the study of a vocal rare species suggests that similar rare species could be studied in the same way. Threshold values for percent forest cover and paved roads will be valuable in developing conservation strategies for the protection of this species. In Chapter Four, we investigated the effectiveness of a sustainable use forest reserve in facilitating connectivity for the Geoffroy’s Spider monkey between two National Parks. We specifically evaluated occurrence across the reserve, habitat suitability, barriers to connectivity and potential mitigation strategies to improve connectivity in the region. We found that the Golfo Dulce Forest Reserve is acting as a buffer to Corcovado National Park and is able to support populations of the Geoffroy’s spider monkey, however, as occurrence was limited to the area surrounding Corcovado, it is possible that it is not facilitating connectivity as intended. Primary road and low forest cover were the most important predictors of poor habitat suitability, both acting as barriers to connectivity and potentially impeding the conservation of an endangered species. This is problematic since Piedras Blancas National Park serves as a connection between the Osa Peninsula and populations of the Geoffroy’s spider monkey in other areas of Costa Rica. In summary, we have shown how PAM, combined with computational approaches, can be used to effectively monitor trends at both fine temporal scales and wide spatial scales across a tropical ecosystem. PAM has provided an effective and rapid approach to monitor trends in biological communities across disturbance gradients, to study rare species across a challenging environment and to evaluate the effectiveness of current management interventions, overcoming many of the key logistical and technical challenges associated with biodiversity monitoring. These methods have revealed important information regarding how anthropogenic disturbance, related to land use change and human development, are threatening both species and communities, which can contribute to setting targets and developing conservation strategies for the protection of biodiversity in the Osa region and beyond.Open Acces

Multimodal and Multifunctional Signaling? – Web Reduction Courtship Behavior in a North American Population of the False Black Widow Spider

Males of widow spiders courting on the web of females engage in web-reduction behavior which entails excising a section of the web, bundling it up, and wrapping it with their silk. Males of the false black widow spider, Steatoda grossa, in European populations also produce stridulatory courtship sound which has not yet been studied in their invaded North American range. Working with a North American population of S. grossa, we tested the hypotheses that (1) web reduction by males renders webs less attractive to rival males; (2) deposition of silk by courting males has an inter-sexual (male-female) signal function that enhances their likelihood of copulation; and (3) stridulatory sound is a courtship signal of males. Testing anemotactic attraction of males in Y-tube olfactometer experiments revealed that reduced webs (indicative of a mated female) and intact webs (indicative of a virgin female) were equally attractive to males. Recording courtship behavior of males with either functional (silk-releasing) spinnerets or spinnerets experimentally occluded on the web of virgin females showed that males with functional spinnerets were more likely to copulate with the female they courted. Although males possess the stridulatory apparatus to produce courtship sound, they did not stridulate when courting or copulating on the web of females. Our data support the conclusion that web-reduction behavior of S. grossa males in their invaded North American range has no long-range effect on mate seeking males. Instead, web-reduction behavior has an inter-sexual signaling function that seems to be linked to functional spinnerets of the courting male. The signal produced by a male likely entails a volatile silk-borne pheromone, but may also embody a gauge of his endurance (the amount of time he engages in web reduction causing web vibrations)

Soundscape in Urban Forests

This Special Issue of Forests explores the role of soundscapes in urban forested areas. It is comprised of 11 papers involving soundscape studies conducted in urban forests from Asia and Africa. This collection contains six research fields: (1) the ecological patterns and processes of forest soundscapes; (2) the boundary effects and perceptual topology; (3) natural soundscapes and human health; (4) the experience of multi-sensory interactions; (5) environmental behavior and cognitive disposition; and (6) soundscape resource management in forests

Traffic Noise and Sexual Selection: Studies of Anthropogenic Impact on Bird Songs and Undergraduate Student Reasoning of Evolutionary Mechanisms

Humans have transformed much of the natural landscape and are continuing to do so at an accelerated rate, compromising natural areas that serve as important habitat for many species. Roads impact much of the environment as they fragment habitat and introduce traffic noise into the acoustic environment, deferentially affecting wildlife in roadside habitat. I explored how traffic noise affects the detection of birds based on whether their vocalizations were masked by traffic noise. Masked species detection was not affected by an increase in traffic noise amplitude, while there was a negative effect of traffic noise amplitude on unmasked species detection, an unexpected result. Conducting more experiments on individual species detection will help ecologists better understand the changes in behavior that influence detection. The effect of human activity on the environment should be better understood by more than just ecologists. Yet, people in the United States fall behind other developed countries in their understanding of many scientific processes, such as evolution. Improved evolutionary knowledge leads people to have a higher acceptance of evolution, and biology educators are responsible for improving evolution education to promote more acceptance. For example, biology students seem committed to survival-based reasoning of evolution, but there are other important evolutionary forces to consider, such as sexual selection. Multiple selection pressures can act on a species, including pressures that select for traits that are maladaptive for survival. Through interviews, we explored how selection for the same and different trait variants affected student reasoning of evolution. When asked to describe evolution in a scenario where selection favored the same variant of a trait, students relied on survival-based reasoning. When students were presented with a scenario where different selection pressures selected for different trait variants, most students described how sexual selection acted on the traits of the population and included reproductive potential as a component of fitness and inheritance in their descriptions of evolution. Teaching examples with scenarios where different selection pressures are selecting for different traits may improve student ability to reason about the role of sexual selection in evolution and the role of reproductive potential in fitness, improving overall understanding of evolution. Advisor: Joseph T. Daue

Traffic Noise and Sexual Selection: Studies of Anthropogenic Impact on Bird Songs and Undergraduate Student Reasoning of Evolutionary Mechanisms

Humans have transformed much of the natural landscape and are continuing to do so at an accelerated rate, compromising natural areas that serve as important habitat for many species. Roads impact much of the environment as they fragment habitat and introduce traffic noise into the acoustic environment, deferentially affecting wildlife in roadside habitat. I explored how traffic noise affects the detection of birds based on whether their vocalizations were masked by traffic noise. Masked species detection was not affected by an increase in traffic noise amplitude, while there was a negative effect of traffic noise amplitude on unmasked species detection, an unexpected result. Conducting more experiments on individual species detection will help ecologists better understand the changes in behavior that influence detection. The effect of human activity on the environment should be better understood by more than just ecologists. Yet, people in the United States fall behind other developed countries in their understanding of many scientific processes, such as evolution. Improved evolutionary knowledge leads people to have a higher acceptance of evolution, and biology educators are responsible for improving evolution education to promote more acceptance. For example, biology students seem committed to survival-based reasoning of evolution, but there are other important evolutionary forces to consider, such as sexual selection. Multiple selection pressures can act on a species, including pressures that select for traits that are maladaptive for survival. Through interviews, we explored how selection for the same and different trait variants affected student reasoning of evolution. When asked to describe evolution in a scenario where selection favored the same variant of a trait, students relied on survival-based reasoning. When students were presented with a scenario where different selection pressures selected for different trait variants, most students described how sexual selection acted on the traits of the population and included reproductive potential as a component of fitness and inheritance in their descriptions of evolution. Teaching examples with scenarios where different selection pressures are selecting for different traits may improve student ability to reason about the role of sexual selection in evolution and the role of reproductive potential in fitness, improving overall understanding of evolution. Advisor: Joseph T. Daue