@article {58197, title = {Acoustically advertising male harbour seals in southeast Alaska do not make biologically relevant acoustic adjustments in the presence of vessel noise}, year = {2020}, abstract = {

Aquatically breeding harbour seal (Phoca vitulina) males use underwater vocalizations during the breeding season to establish underwater territories, defend territories against intruder males, and possibly to attract females. Vessel noise overlaps in frequency with these vocalizations and could negatively impact breeding success by limiting communication space. In this study, we investigated whether harbour seals employed anti-masking strategies to maintain communication in the presence of vessel noise in Glacier Bay National Park and Preserve, Alaska. Harbour seals in this location did not sufficiently adjust source levels or acoustic parameters of vocalizations to compensate for acoustic masking. Instead, for every 1 dB increase in ambient noise, signal excess decreased by 0.84 dB, indicating a reduction in communication space when vessels passed. We suggest that harbour seals may already be acoustically advertising at or near a biologically maximal sound level and therefore lack the ability to increase call amplitude to adjust to changes in their acoustic environment. This may have significant implications for this aquatically breeding pinniped, particularly for populations in high noise regions.

}, keywords = {acoustic communication, harbour seals, marine mammals, Noise, vocalizations}, doi = {10.1098/rsbl.2019.0795}, url = {https://royalsocietypublishing.org/doi/10.1098/rsbl.2019.0795}, author = {Matthews, Leanna P. and Fournet, Michelle E. H. and Gabriele, Christine and Klinck, Holger and Parks, Susan E.} } @article {57907, title = {Gaps in terrestrial soundscape research: it{\textquoteright}s time to focus on tropical wildlife}, year = {2019}, abstract = {

There has been a body of research examining the sounds produced in landscapes. These sounds are commonly defined as soundscapes, however, the term is often used in different contexts. To understand how the various meanings attributed to soundscapes, we identified how soundscapes are represented in the scientific literature and identified current knowledge gaps in soundscape research focusing on terrestrial environments. We conducted a quantitative review of published papers with the keyword soundscape available at Web of Science and Scopus databases. A total of 1,309 abstracts and a subset of about 5\% (N=68) complete papers and reviews published from 1985 to 2017 were read and analysed, identifying types of sound, types of environment and focal species studied, as well as study regions and climates. By identifying the current focus of research, we also identified gaps and research opportunities. Research was biased towards temperate regions, terrestrial environments, and the impacts on humans in urban areas. Although most of the world\’s biodiversity is concentrated in tropical wilderness areas, these regions had fewer studies attributed to them. Given the importance of tropical landscapes for biodiversity conservation, we strongly suggest that more research should be undertaken in the tropics, with a particular focus on wildlife in these regions. Furthermore, soundscape research (methods and tools) should increasingly target the anthropogenic impacts on wildlife, including behavioural and physiological changes, alongside the current focus on human-sound interactions and the approach used by bioacoustics methods.

}, keywords = {bioacoustics, gap analysis, landscape, Noise, review, sound}, doi = {10.1016/j.scitotenv.2019.135403}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969719353963}, author = {Marina D. A. Scarpelli and Cezar Ribeiro, Milton and Teixeira, Fernanda Z. and Young, Robert J. and Teixeira, Camila P.} } @article {53577, title = {Evidence of the environmental impact of noise pollution on biodiversity: a systematic map protocol}, journal = {Environmental Evidence}, volume = {8}, year = {2019}, month = {Jan-12-2019}, abstract = {

Background

For decades, biodiversity has suffered massive losses worldwide. Urbanization is one of the major drivers of extinction because it leads to the physical fragmentation and loss of natural habitats and it is associated with related effects, e.g. pollution and in particular noise pollution given that many man-made sounds are generated in cities (e.g. industrial and traffic noise, etc.). However, all human activities generate sounds, even far from any human habitation (e.g. motor boats on lakes, aircraft in the air, etc.). Ecological research now deals increasingly with the effects of noise pollution on biodiversity. Many studies have shown the impacts of anthropogenic noise and concluded that it is potentially a threat to life on Earth. The present work describes a protocol to systematically map evidence of the environmental impact of noise pollution on biodiversity. The resulting map will inform on the species most studied and on the demonstrated impacts. This will be useful for further primary research by identifying knowledge gaps and in view of further analysis, such as systematic reviews.

Methods

Searches will include peer-reviewed and grey literature published in English and French. Two online databases will be searched using English terms and search consistency will be assessed with a test list. No geographical restrictions will be applied. The subject population will include all species. Exposures will include all types of man-made sounds (industrial, traffic, etc.) in all types of environments (or media) (terrestrial, aerial, aquatic), including all contexts and sound origins (spontaneous or recorded sounds, in situ or laboratory studies, etc.). All relevant outcomes will be considered (space use, reproduction, communication, abundance, etc.). An open-access database will be produced with all relevant studies selected during the three screening stages. For each study, the database will contain metadata on key variables of interest (species, types of sound, outcomes, etc.). This database will be available in conjunction with a map report describing the mapping process and the evidence base with summary figures and tables of the study characteristics.

}, keywords = {Anthropogenic sounds, ecosystems, Impact of urbanization, Man-made sounds, Masking auditory, Natural habitats, Noise, Pollution, Species loss, Traffic noise, urban noise}, doi = {10.1186/s13750-019-0146-6}, url = {https://environmentalevidencejournal.biomedcentral.com/articles/10.1186/s13750-019-0146-6}, author = {Sordello, Romain and Flamerie De Lachapelle, Fr{\'e}d{\'e}rique and Livoreil, Barbara and Vanpeene, Sylvie} } @article {53540, title = {Noise as an informational cue for decision-making: the sound of rain delays bat emergence}, journal = {The Journal of Experimental Biology}, year = {2019}, month = {Sep-01-2020}, pages = {jeb.192005}, abstract = {

Background noise can have strong negative consequences on animals, reducing individual fitness by masking communication signals, impeding prey detection and increasing predation risk. While the negative impacts of noise across taxa have been well documented, the use of noise as an informational cue, providing animals with reliable information on environmental conditions has been less well studied. In the tropical rainforest, downpours can be intense and frequent. Strong rainfall may impede efficient orientation and foraging for bats that need echolocation to both navigate and detect prey, and can result in higher flight costs due to increased metabolic rates. Using playback experiments at natural roosts we tested whether two bat species, differing in their hunting strategies and foraging habitats, use rain noise as a cue to delay emergence from their roosts. We found that both species significantly delayed their emergence time during rain noise playbacks compared to silence and ambient noise controls. We conclude that bats can use background noise, here the acoustic component of rainfall, as a reliable informational cue to make informed decisions, here about whether to initiate foraging trips or remain in the shelter of their roosts. Our findings suggest that environmental background noise can sometimes be beneficial to animals, in particular in situations where other sensory cues may be absent.

}, keywords = {bats, decision-making, foraging, information cues, Noise, rain}, issn = {0022-0949}, doi = {10.1242/jeb.192005}, url = {http://jeb.biologists.org/lookup/doi/10.1242/jeb.192005https://syndication.highwire.org/content/doi/10.1242/jeb.192005https://syndication.highwire.org/content/doi/10.1242/jeb.192005}, author = {Geipel, Inga and Smeekes, Marcus J. and Halfwerk, Wouter and Rachel A. Page} } @article {53527, title = {Bats increase vocal amplitude and decrease vocal complexity to mitigate noise interference during social communication}, journal = {Animal Cognition}, year = {2019}, month = {Oct-01-2019}, abstract = {

Natural background noises are common in the acoustic environments in which most organisms have evolved. Therefore, the vocalization and sound perception systems of vocal animals are inherently equipped to overcome natural background noise. Human-generated noises, however, pose new challenges that can hamper audiovocal communication. The mechanisms animals use to cope with anthropogenic noise disturbances have been extensively explored in a variety of taxa. Bats emit echolocation pulses primarily to orient, locate and navigate, while social calls are used to communicate with conspecifics. Previous studies have shown that bats alter echolocation pulse parameters in response to background noise interference. In contrast to high-frequency echolocation pulses, relatively low-frequency components within bat social calls overlap broadly with ambient noise frequencies. However, how bats structure their social calls in the presence of anthropogenic noise is not known. Here, we hypothesized that bats leverage vocal plasticity to facilitate vocal exchanges within a noisy environment. To test this hypothesis, we subjected the Asian particolored bat, Vespertilio sinensis, to prerecorded traffic noise. We observed a significant decrease in vocal complexity (i.e., an increased frequency of monosyllabic calls) in response to traffic noise. However, an increase in the duration and frequency of social calls, as have been observed in other species, was not evident. This suggests that signal simplification may increase communication efficacy in noisy environments. Moreover, V. sinensis also increased call amplitude in response to increased traffic noise, consistent with the predictions of the Lombard effect.

}, keywords = {acoustic communication, bats, Noise, Social calls, vocal plasticity}, issn = {1435-9448}, doi = {10.1007/s10071-018-01235-0}, url = {http://link.springer.com/10.1007/s10071-018-01235-0}, author = {Jiang, Tinglei and Guo, Xiong and Lin, Aiqing and Wu, Hui and Sun, Congnan and Feng, Jiang and Kanwal, Jagmeet S.} }