108 research outputs found
Equity and career-life balance in marine mammal science?
It is widely acknowledged that family and care-giving responsibilities are driving women away from Science, Technology, Engineering, and Mathematics (STEM) fields. Marine mammal science often incurs heavy fieldwork and travel obligations, which make it a challenging career in which to find work-life balance. This opinion piece explores gender equality, equity (the principles of fairness that lead to equality), and work-life balance in science generally and in this field in particular. We aim to (1) raise awareness of these issues among members of the Society for Marine Mammalogy; (2) explore members’ attitudes and viewpoints collected from an online survey and further discussion at a biennial conference workshop in 2015; and (3) make suggestions for members to consider for action, or for the Board of Governors to consider in terms of changes to policy or procedures. Leaks in our pipeline—the attrition of women, and others with additional caring responsibilities—represent an intellectual and economic loss. By striving for equity and promoting work-life balance, we will help to ensure a healthy and productive Society better able to succeed in its aims promoting education, high quality research, conservation, and management of marine mammals.Publisher PDFPeer reviewe
Acoustic performance of a 50.8-cm (20-inch) diameter variable-pitch fan and inlet. Volume 2: Acoustic data
Results from acoustic tests on a 50.8 cm (20 inch) QCSEE Under-the-Wing (UTW) engine, variable pitch fan and inlet simulator are tabulated. Tests were run in both forward and reverse thrust mdoes with a bellmouth inlet, five accelerating inlets (one hardwall and four treated), and four low Mach number inlets (one hardwall and three treated). The 1/3 octave-band acoustic data are presented for the model size on the measured 5.2 m (17.0 ft) arc and also data scaled to full QCSEE size 71:20 on a 152.4 m (500 ft) sideline
Call repertoire and inferred ecotype presence of killer whales (\u3ci\u3eOrcinus orca\u3c/i\u3e) recorded in the southeastern Chukchi Sea
Killer whales occur in the Arctic but few data exist regarding the ecotypes present. The calling behavior differs among ecotypes, which can be distinguished based on pulsed call type, call rate, and bandwidth. In this study, a passive acoustic recorder was deployed 75 km off Point Hope, Alaska, in the southeastern Chukchi Sea to identify which ecotypes were present. A total of 1323 killer whale pulsed calls were detected on 38 of 276 days during the summers (June–August) of 2013–2015. The majority of calls (n = 804, 61%) were recorded in 2013 with the most calls recorded in July (76% of total calls). The calls were manually grouped into six categories: multipart, downsweep, upsweep, modulated, single modulation, and flat. Most detections were flat (n = 485, 37%) or multipart calls (n = 479, 36%), which contained both high and low frequency components. Call comparisons with those reported in the published literature showed similarities with other transient populations in fundamental frequency contour point distribution and median frequency. This study provides the first comprehensive catalog of transient killer whale calls in this region as well as reports on previously undescribed calls
Humpback Whale Song and Foraging Behavior on an Antarctic Feeding Ground
The article of record as published may be located at http://dx.doi.org/10.1371/journal.pone.0051214Reports of humpback whale (Megaptera novaeangliae) song chorusing occuring outside the breeding grounds are becoming more common, but song structure and underwater behavior of individual singers on feeding grounds and migration routes remain unknown. Here, ten humpback whales in the Western Antarctic Peninsula were tagged in May 2010 with non-invasive, suction-cup attached tags to study foraging ecology and acoustic behavior. Background song was identified on all ten records, but additionally, acoustic records of two whales showed intense and continuous singing, with a level of organization and structure approaching that of typical breeding ground song. The songs, produced either by the tagged animalsor close associates, shared phrase types and theme structure with one another, and some song bouts lasted close to an hour. Dive behavior of tagged animals during the time of sound production showed song occurring during periods of active diving, sometimes to depths greater than 100 m. One tag record also contained song in the presence of feeding lunges identified from the behavioral sensors, indicating that mating displays occur in areas worthy of foraging. These data show behavioral flexibility as the humpbacks manage competing needs to continue to feed and prepare for the breeding season during late fall. This may also signify an ability to engage in breeding activities outside of the traditional, warm water breeding ground locations.This material is based upon work supported by the National Science Foundation under Grant No. ANT-07-39483. The authors also greatefully acknowledge funding support from the F.V. Hunt Fellowship of the Acoustical Society of America
Common humpback whale (Megaptera novaeangliae) sound types for passive acoustic monitoring
Author Posting. © Acoustical Society of America, 2011. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 129 (2011): 476-482, doi:10.1121/1.3504708.Humpback whales (Megaptera novaeangliae) are one of several baleen whale species in the Northwest Atlantic that coexist with vessel traffic and anthropogenic noise. Passive acoustic monitoring strategies can be used in conservation management, but the first step toward understanding the acoustic behavior of a species is a good description of its acoustic repertoire. Digital acoustic tags (DTAGs) were placed on humpback whales in the Stellwagen Bank National Marine Sanctuary to record and describe the non-song sounds being produced in conjunction with foraging activities. Peak frequencies of sounds were generally less than 1 kHz, but ranged as high as 6 kHz, and sounds were generally less than 1 s in duration. Cluster analysis distilled the dataset into eight groups of sounds with similar acoustic properties. The two most stereotyped and distinctive types (“wops” and “grunts”) were also identified aurally as candidates for use in passive acoustic monitoring. This identification of two of the most common sound types will be useful for moving forward conservation efforts on this Northwest Atlantic feeding ground.This paper was funded by the National Oceanic
and Atmospheric Administration (NOAA)’s National
Marine Sanctuaries Program. It was also sponsored in part
by the University of Hawaii Sea Grant College Program,
School of Ocean and Earth Science and Technology, under
Institutional Grant No. NA05OAR4171048 from the NOAA
Office of Sea Grant, Department of Commerce
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Context-dependent lateralized feeding strategies in blue whales.
Lateralized behaviors benefit individuals by increasing task efficiency in foraging and anti-predator behaviors [1-4]. The conventional lateralization paradigm suggests individuals are left or right lateralized, although the direction of this laterality can vary for different tasks (e.g. foraging or predator inspection/avoidance). By fitting tri-axial movement sensors to blue whales (Balaenoptera musculus), and by recording the direction and size of their rolls during lunge feeding events, we show how these animals differ from such a paradigm. The strength and direction of individuals' lateralization were related to where and how the whales were feeding in the water column. Smaller rolls (≤180°) predominantly occurred at depth (>70 m), with whales being more likely to rotate clockwise around their longest axis (right lateralized). Larger rolls (>180°), conversely, occurred more often at shallower depths (<70 m) and were more likely to be performed anti-clockwise (left lateralized). More acrobatic rolls are typically used to target small, less dense krill patches near the water's surface [5,6], and we posit that the specialization of lateralized feeding strategies may enhance foraging efficiency in environments with heterogeneous prey distributions
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Behavioral responses of fin whales to military mid-frequency active sonar
Funding. Primary funding for the SOCAL-BRS project was initially provided by the US Navy’s Chief of Naval Operations Environmental Readiness Division and subsequently by the US Navy’s Living Marine Resources (LMR) Program. Additional support for environmental sampling and logistics was also provided by the Office of Naval Research, Marine Mammal Program.The effect of active sonars on marine mammal behavior is a topic of considerable interest and scientific investigation. Some whales, including the largest species (blue whales, Balaenoptera musculus), can be impacted by mid-frequency (1-10 kHz) military sonars. Here we apply complementary experimental methods to provide the first experimentally controlled measurements of behavioral responses to military sonar and similar stimuli for a related endangered species, fin whales (Balaenoptera physalus). Analytical methods include: (1) Principal Component Analysis paired with Generalized Additive Mixed Models; (2) Hidden Markov Models; and (3) structured expert elicitation using response severity metrics. These approaches provide complementary perspectives on the nature of potential changes within and across individuals. Behavioral changes were detected in five of 15 whales during controlled exposure experiments (CEEs) using mid-frequency active sonar (MFAS) or pseudorandom noise (PRN) of similar frequency, duration, and source and received level. No changes were detected during six control (no noise) sequences. Overall responses were more limited in occurrence, severity, and duration than in blue whales and were less dependent upon contextual aspects of exposure and more contingent upon exposure received level. Quantifying the factors influencing marine mammal responses to sonar is critical in assessing and mitigating future impacts.Publisher PDFPeer reviewe
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Prey-mediated behavioral responses of feeding blue whales in controlled sound exposure experiments
Behavioral response studies provide significant insights into the nature, magnitude, and consequences of changes in animal behavior in response to some external stimulus. Controlled exposure experiments (CEEs) to study behavioral response have faced challenges in quantifying the importance of and interaction among individual variability, exposure conditions, and environmental covariates. To investigate these complex parameters relative to blue whale behavior and how it may change as a function of certain sounds, we deployed multi-sensor acoustic tags and conducted CEEs using simulated mid-frequency active sonar (MFAS) and pseudo-random noise (PRN) stimuli, while collecting synoptic, quantitative prey measures. In contrast to previous approaches that lacked such prey data, our integrated approach explained substantially more variance in blue whale dive behavioral responses to mid-frequency sounds (r² = 0.725 vs. 0.14 previously). Results demonstrate that deep-feeding whales respond more clearly and strongly to CEEs than those in other behavioral states, but this was only evident with the increased explanatory power provided by incorporating prey density and distribution as contextual covariates. Including contextual variables increases the ability to characterize behavioral variability and empirically strengthens previous findings that deep-feeding blue whales respond significantly to mid-frequency sound exposure. However, our results are only based on a single behavioral state with a limited sample size, and this analytical framework should be applied broadly across behavioral states. The increased capability to describe and account for individual response variability by including environmental variables, such as prey, that drive foraging behavior underscores the importance of integrating these and other relevant contextual parameters in experimental designs. Our results suggest the need to measure and account for the ecological dynamics of predator–prey interactions when studying the effects of anthropogenic disturbance in feeding animals.This is the publisher’s final pdf. The published article is copyrighted by the Ecological Society of America and can be found at: http://esajournals.onlinelibrary.wiley.com/hub/journal/10.1002/%28ISSN%291939-5582/Keywords: foraging behavior, disturbance, whales, controlled exposure experiment, prey, behavioral respons
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Evidence for acoustic communication among bottom foraging humpback whales
Humpback whales (Megaptera novaeangliae), a mysticete with a cosmopolitan distribution, demonstrate
marked behavioural plasticity. Recent studies show evidence of social learning in the transmission of specific
population level traits ranging from complex singing to stereotyped prey capturing behaviour. Humpback
whales have been observed to employ group foraging techniques, however details on how individuals
coordinate behaviour in these groups is challenging to obtain. This study investigates the role of a novel
broadband patterned pulsed sound produced by humpback whales engaged in bottom-feeding behaviours,
referred to here as a ‘paired burst’ sound. Data collected from 56 archival acoustic tag deployments were
investigated to determine the functional significance of these signals. Paired burst sound production was
associated exclusively with bottom feeding under low-light conditions, predominantly with evidence of
associated conspecifics nearby suggesting that the sound likely serves either as a communicative signal to
conspecifics, a signal to affect prey behaviour, or possibly both. This study provides additional evidence for
individual variation and phenotypic plasticity of foraging behaviours in humpback whales and provides
important evidence for the use of acoustic signals among foraging individuals in this species
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