The Experts below are selected from a list of 3816 Experts worldwide ranked by ideXlab platform
Purnima Ratilal - One of the best experts on this subject based on the ideXlab platform.
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Vocalization source level distributions and pulse compression gains of diverse Baleen Whale species in the Gulf of Maine
Journal of the Acoustical Society of America, 2016Co-Authors: Delin Wang, Wei Huang, Heriberto A. Garcia, Nicholas C. Makris, Purnima RatilalAbstract:The vocalization source level distributions and pulse compression gains are estimated for four distinct Baleen Whale species in the Gulf of Maine: blue, fin, minke, and sei. The vocalizations were received on a large-aperture densely sampled coherent hydrophone array system deployed to monitor marine mammals over instantaneous wide areas using the passive ocean acoustic waveguide remote sensing technique. For each Baleen Whale species, between 400 to over 1400 measured vocalizations with significantly high signal-to-noise ratios (SNR>10 dB) after coherent beamforming and localized with high accuracies (
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vocalization source level distributions and pulse compression gains of diverse Baleen Whale species in the gulf of maine
Journal of the Acoustical Society of America, 2016Co-Authors: Delin Wang, Wei Huang, Heriberto A. Garcia, Nicholas C. Makris, Purnima RatilalAbstract:The vocalization source level distributions and pulse compression gains are estimated for four distinct Baleen Whale species in the Gulf of Maine: blue, fin, minke, and sei. The vocalizations were received on a large-aperture densely sampled coherent hydrophone array system deployed to monitor marine mammals over instantaneous wide areas using the passive ocean acoustic waveguide remote sensing technique. For each Baleen Whale species, between 400 to over 1400 measured vocalizations with significantly high signal-to-noise ratios (SNR>10 dB) after coherent beamforming and localized with high accuracies (<10% localization errors) over ranges spanning roughly 1 km to 38 km are included in the analysis. The Whale vocalization received pressure levels are corrected for broadband transmission losses modelled using a calibrated parabolic equation based acoustic propagation model for a random range-dependent ocean waveguide. The broadband vocalization equivalent pulse-compression gains are found to be 2.5±1.1 for...
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Vocalization Source Level Distributions and Pulse Compression Gains of Diverse Baleen Whale Species in the Gulf of Maine
Remote Sensing, 2016Co-Authors: Delin Wang, Wei Huang, Heriberto A. Garcia, Purnima RatilalAbstract:The vocalization source level distributions and pulse compression gains are estimated for four distinct Baleen Whale species in the Gulf of Maine: fin, sei, minke and an unidentified Baleen Whale species. The vocalizations were received on a large-aperture densely-sampled coherent hydrophone array system useful for monitoring marine mammals over instantaneous wide areas via the passive ocean acoustic waveguide remote sensing technique. For each Baleen Whale species, between 125 and over 1400 measured vocalizations with significantly high Signal-to-Noise Ratios (SNR > 10 dB) after coherent beamforming and localized with high accuracies (
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vocalization source level distributions and pulse compression gains of diverse Baleen Whale species in the gulf of maine
Remote Sensing, 2016Co-Authors: Delin Wang, Wei Huang, Heriberto A. Garcia, Purnima RatilalAbstract:The vocalization source level distributions and pulse compression gains are estimated for four distinct Baleen Whale species in the Gulf of Maine: fin, sei, minke and an unidentified Baleen Whale species. The vocalizations were received on a large-aperture densely-sampled coherent hydrophone array system useful for monitoring marine mammals over instantaneous wide areas via the passive ocean acoustic waveguide remote sensing technique. For each Baleen Whale species, between 125 and over 1400 measured vocalizations with significantly high Signal-to-Noise Ratios (SNR > 10 dB) after coherent beamforming and localized with high accuracies (<10% localization errors) over ranges spanning roughly 1 km–30 km are included in the analysis. The Whale vocalization received pressure levels are corrected for broadband transmission losses modeled using a calibrated parabolic equation-based acoustic propagation model for a random range-dependent ocean waveguide. The Whale vocalization source level distributions are characterized by the following means and standard deviations, in units of dB re 1 μ Pa at 1 m: 181.9 ± 5.2 for fin Whale 20-Hz pulses, 173.5 ± 3.2 for sei Whale downsweep chirps, 177.7 ± 5.4 for minke Whale pulse trains and 169.6 ± 3.5 for the unidentified Baleen Whale species downsweep calls. The broadband vocalization equivalent pulse-compression gains are found to be 2.5 ± 1.1 for fin Whale 20-Hz pulses, 24 ± 10 for the unidentified Baleen Whale species downsweep calls and 69 ± 23 for sei Whale downsweep chirps. These pulse compression gains are found to be roughly proportional to the inter-pulse intervals of the vocalizations, which are 11 ± 5 s for fin Whale 20-Hz pulses, 29 ± 18 for the unidentified Baleen Whale species downsweep calls and 52 ± 33 for sei Whale downsweep chirps. The source level distributions and pulse compression gains are essential for determining signal-to-noise ratios and hence detection regions for Baleen Whale vocalizations received passively on underwater acoustic sensing systems, as well as for assessing communication ranges in Baleen Whales.
Ewan R Fordyce - One of the best experts on this subject based on the ideXlab platform.
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gigantism precedes filter feeding in Baleen Whale evolution
Current Biology, 2018Co-Authors: Ewan R Fordyce, Felix G MarxAbstract:Summary Baleen Whales (Mysticeti) are the largest animals on Earth, thanks to their ability to filter huge volumes of small prey from seawater. Mysticetes appeared during the Late Eocene, but evidence of their early evolution remains both sparse and controversial [1, 2], with several models competing to explain the origin of Baleen-based bulk feeding [3–6]. Here, we describe a virtually complete skull of Llanocetus denticrenatus , the second-oldest (ca. 34 Ma) mysticete known. The new material represents the same individual as the type and only specimen, a fragmentary mandible. Phylogenetic analysis groups Llanocetus with the oldest mysticete, Mystacodon selenensis [2], into the basal family Llanocetidae. Llanocetus is gigantic (body length ∼8 m) compared to other early mysticetes [7–9]. The broad rostrum has sharp, widely spaced teeth with marked dental abrasion and attrition, suggesting biting and occlusal shearing. As in extant mysticetes, the palate bears many sulci, commonly interpreted as osteological correlates of Baleen [3]. Unexpectedly, these sulci converge on the upper alveoli, suggesting a peri-dental blood supply to well-developed gums, rather than to inter-alveolar racks of Baleen. We interpret Llanocetus as a raptorial or suction feeder, revealing that Whales evolved gigantism well before the emergence of filter feeding. Rather than driving the origin of mysticetes, Baleen and filtering most likely only arose after an initial phase of suction-assisted raptorial feeding [2, 4, 5]. This scenario differs strikingly from that proposed for odontocetes, whose defining adaptation—echolocation—was present even in their earliest representatives [10].
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a new archaic Baleen Whale toipahautea waitaki early late oligocene new zealand and the origins of crown mysticeti
Royal Society Open Science, 2018Co-Authors: Cheng-hsiu Tsai, Ewan R FordyceAbstract:A new genus and species of extinct Baleen Whale †Toipahautea waitaki (Late Oligocene, New Zealand) is based on a skull and associated bones, from the lower Kokoamu Greensand, about 27.5 Ma (local u...
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trace fossil evidence of predation upon bone eating worms on a Baleen Whale skeleton from the oligocene of new zealand
Lethaia, 2015Co-Authors: Robert W. Boessenecker, Ewan R FordyceAbstract:The osteophagous worm Osedax (Annelida: Siboglinidae) colonizes vertebrate bones in deep-sea environments globally. Osedax bioerosion of modern bones suggests a potentially destructive agent in the marine vertebrate fossil record, but the dearth of published reports of abundant Osedax traces suggests an uncertain taphonomic influence of this organism. This study reports Osedax traces (Osspecus boreholes, pockmarks and collapsed galleries) in an Oligocene Baleen Whale (Cetacea: Eomysticetidae) from New Zealand, which constitute the first record of fossil Osedax traces from the southern hemisphere. Some Osedax traces are cross-cut by linear biogenic scrape marks, implying that sharks or bony fish fed upon Osedax worms, a process which compounds or potentially accelerates worm-inflicted damage to vertebrate bones in marine environments.
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juvenile morphology in Baleen Whale phylogeny
Naturwissenschaften, 2014Co-Authors: Cheng-hsiu Tsai, Ewan R FordyceAbstract:Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living Baleen Whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei Whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right Whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in Baleen Whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.
Cheng-hsiu Tsai - One of the best experts on this subject based on the ideXlab platform.
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a new archaic Baleen Whale toipahautea waitaki early late oligocene new zealand and the origins of crown mysticeti
Royal Society Open Science, 2018Co-Authors: Cheng-hsiu Tsai, Ewan R FordyceAbstract:A new genus and species of extinct Baleen Whale †Toipahautea waitaki (Late Oligocene, New Zealand) is based on a skull and associated bones, from the lower Kokoamu Greensand, about 27.5 Ma (local u...
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northern pygmy right Whales highlight quaternary marine mammal interchange
Current Biology, 2017Co-Authors: Cheng-hsiu Tsai, Rita Catanzariti, Alberto Collareta, Mark Bosselaers, Erich M G Fitzgerald, Felix G Marx, Naoki Kohno, Gianni Insacco, Agatino Reitano, Masayuki OishiAbstract:Summary The pygmy right Whale, Caperea marginata , is the most enigmatic living Whale. Little is known about its ecology and behaviour, but unusual specialisations of visual pigments [1], mitochondrial tRNAs [2], and postcranial anatomy [3] suggest a lifestyle different from that of other extant Whales. Geographically, Caperea represents the only major Baleen Whale lineage entirely restricted to the Southern Ocean. Caperea -like fossils, the oldest of which date to the Late Miocene, are exceedingly rare and likewise limited to the Southern Hemisphere [4], despite a more substantial history of fossil sampling north of the equator. Two new Pleistocene fossils now provide unexpected evidence of a brief and relatively recent period in geological history when Caperea occurred in the Northern Hemisphere (Figure 1A,B).
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a miocene breeding ground of an extinct Baleen Whale cetacea mysticeti
PeerJ, 2017Co-Authors: Cheng-hsiu TsaiAbstract:Locating breeding sites is definitely a key to understanding the ecological requirements and maintaining the sustainability of populations/species. Here I re-examined published specimens of an extinct Baleen Whale, Parietobalaena yamaokai, from the lower part of Itahashi Formation (16.1-15.6 Ma, Middle Miocene) in Shobara, Hiroshima, Japan. A critical and previously unnoticed feature, the open suture between the supraoccipital and exoccipital, in one specimen indicates the preservation of a very young individual-under six months old and even close to a new-born calf. Given the occurrence of a new-born Whale and relatively abundant assemblage of Parietobalaena yamaokai, I propose a previously hidden and unknown breeding ground for the extinct Baleen Whale, P. yamaokai, in the Middle Miocene of Shobara (16.1-15.6 Ma), Hiroshima. Discovery of paleo-breeding sites of extinct populations/species should further help us to understand biological extinctions from a long-term perspective as conservation paleobiology aims to offer new insights into policy making for conserving endangered populations/species.
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juvenile morphology in Baleen Whale phylogeny
Naturwissenschaften, 2014Co-Authors: Cheng-hsiu Tsai, Ewan R FordyceAbstract:Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living Baleen Whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei Whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right Whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in Baleen Whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.
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Disparate Heterochronic Processes in Baleen Whale Evolution
Evolutionary Biology, 2014Co-Authors: Cheng-hsiu Tsai, R. Ewan FordyceAbstract:Skulls of living Baleen Whales show distinctive patterns of heterochronic ontogenetic change with implications for mysticete evolution. Here, three Baleen Whale species are analysed and considered in a heterochronic context. Landmarks show that, during ontogeny, skull morphology changes significantly in the rorqual Balaenoptera borealis and humpback Megaptera novaeangliae (both Balaenopteridae), while the pygmy right Whale Caperea marginata (Cetotheriidae: Neobalaeninae) retains an overall juvenile morphology from foetus to adult. Geometric morphometric analyses show that foetal and adult C . marginata are similar, whereas the balaenopterids are more disparate: foetal M . novaeangliae and B . borealis appear in one group, and adult M . novaeangliae and B . borealis are grouped closely. Heterochrony involves paedomorphosis for Caperea , and peramorphosis for the balaenopterids. Heterochrony might cause limited or released developmental constraints, leading to low taxonomic diversity in the single surviving species of neobalaenine, and higher diversity amongst balaenopterids.
Delin Wang - One of the best experts on this subject based on the ideXlab platform.
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Vocalization source level distributions and pulse compression gains of diverse Baleen Whale species in the Gulf of Maine
Journal of the Acoustical Society of America, 2016Co-Authors: Delin Wang, Wei Huang, Heriberto A. Garcia, Nicholas C. Makris, Purnima RatilalAbstract:The vocalization source level distributions and pulse compression gains are estimated for four distinct Baleen Whale species in the Gulf of Maine: blue, fin, minke, and sei. The vocalizations were received on a large-aperture densely sampled coherent hydrophone array system deployed to monitor marine mammals over instantaneous wide areas using the passive ocean acoustic waveguide remote sensing technique. For each Baleen Whale species, between 400 to over 1400 measured vocalizations with significantly high signal-to-noise ratios (SNR>10 dB) after coherent beamforming and localized with high accuracies (
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vocalization source level distributions and pulse compression gains of diverse Baleen Whale species in the gulf of maine
Journal of the Acoustical Society of America, 2016Co-Authors: Delin Wang, Wei Huang, Heriberto A. Garcia, Nicholas C. Makris, Purnima RatilalAbstract:The vocalization source level distributions and pulse compression gains are estimated for four distinct Baleen Whale species in the Gulf of Maine: blue, fin, minke, and sei. The vocalizations were received on a large-aperture densely sampled coherent hydrophone array system deployed to monitor marine mammals over instantaneous wide areas using the passive ocean acoustic waveguide remote sensing technique. For each Baleen Whale species, between 400 to over 1400 measured vocalizations with significantly high signal-to-noise ratios (SNR>10 dB) after coherent beamforming and localized with high accuracies (<10% localization errors) over ranges spanning roughly 1 km to 38 km are included in the analysis. The Whale vocalization received pressure levels are corrected for broadband transmission losses modelled using a calibrated parabolic equation based acoustic propagation model for a random range-dependent ocean waveguide. The broadband vocalization equivalent pulse-compression gains are found to be 2.5±1.1 for...
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Vocalization Source Level Distributions and Pulse Compression Gains of Diverse Baleen Whale Species in the Gulf of Maine
Remote Sensing, 2016Co-Authors: Delin Wang, Wei Huang, Heriberto A. Garcia, Purnima RatilalAbstract:The vocalization source level distributions and pulse compression gains are estimated for four distinct Baleen Whale species in the Gulf of Maine: fin, sei, minke and an unidentified Baleen Whale species. The vocalizations were received on a large-aperture densely-sampled coherent hydrophone array system useful for monitoring marine mammals over instantaneous wide areas via the passive ocean acoustic waveguide remote sensing technique. For each Baleen Whale species, between 125 and over 1400 measured vocalizations with significantly high Signal-to-Noise Ratios (SNR > 10 dB) after coherent beamforming and localized with high accuracies (
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vocalization source level distributions and pulse compression gains of diverse Baleen Whale species in the gulf of maine
Remote Sensing, 2016Co-Authors: Delin Wang, Wei Huang, Heriberto A. Garcia, Purnima RatilalAbstract:The vocalization source level distributions and pulse compression gains are estimated for four distinct Baleen Whale species in the Gulf of Maine: fin, sei, minke and an unidentified Baleen Whale species. The vocalizations were received on a large-aperture densely-sampled coherent hydrophone array system useful for monitoring marine mammals over instantaneous wide areas via the passive ocean acoustic waveguide remote sensing technique. For each Baleen Whale species, between 125 and over 1400 measured vocalizations with significantly high Signal-to-Noise Ratios (SNR > 10 dB) after coherent beamforming and localized with high accuracies (<10% localization errors) over ranges spanning roughly 1 km–30 km are included in the analysis. The Whale vocalization received pressure levels are corrected for broadband transmission losses modeled using a calibrated parabolic equation-based acoustic propagation model for a random range-dependent ocean waveguide. The Whale vocalization source level distributions are characterized by the following means and standard deviations, in units of dB re 1 μ Pa at 1 m: 181.9 ± 5.2 for fin Whale 20-Hz pulses, 173.5 ± 3.2 for sei Whale downsweep chirps, 177.7 ± 5.4 for minke Whale pulse trains and 169.6 ± 3.5 for the unidentified Baleen Whale species downsweep calls. The broadband vocalization equivalent pulse-compression gains are found to be 2.5 ± 1.1 for fin Whale 20-Hz pulses, 24 ± 10 for the unidentified Baleen Whale species downsweep calls and 69 ± 23 for sei Whale downsweep chirps. These pulse compression gains are found to be roughly proportional to the inter-pulse intervals of the vocalizations, which are 11 ± 5 s for fin Whale 20-Hz pulses, 29 ± 18 for the unidentified Baleen Whale species downsweep calls and 52 ± 33 for sei Whale downsweep chirps. The source level distributions and pulse compression gains are essential for determining signal-to-noise ratios and hence detection regions for Baleen Whale vocalizations received passively on underwater acoustic sensing systems, as well as for assessing communication ranges in Baleen Whales.
Ari S Friedlaender - One of the best experts on this subject based on the ideXlab platform.
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physical speciation and solubility of iron from Baleen Whale faecal material
Marine Chemistry, 2017Co-Authors: Lavenia Ratnarajah, Delphine Lannuzel, Ashley T Townsend, Klaus M Meiners, Stephen Nicol, Ari S FriedlaenderAbstract:Abstract Primary productivity in large areas of the Southern Ocean is limited by the availability of a key micronutrient—iron (Fe). Recently it has been suggested that marine animals could play an important role in recycling Fe through their diet and subsequent defecation, however there is no information on the relative bioavailability of faecal Fe for uptake. The bioavailability of Fe in seawater is controlled by a number of complex interactions. The physical separation between the dissolved ( 0.2 μm) fractions is one common measure used to determine element bioavailability. Here, the size fractionation of Fe from 3 Whale faecal samples in 4 different size classes ( 60 μm) was investigated, along with the leaching of particulate Fe over time. Although the total particulate fraction (> 0.2 μm, 5026–22,526 nmol L − 1 ) dominated the total Fe pool, the concentrations of dissolved Fe in Whale faecal samples (186–754 nmol L − 1 ) were three order of magnitude higher than published Southern Ocean surface seawater concentrations. Furthermore, results from the leaching experiment suggest that Fe is continually leached from faecal particles over an initial 12-hour period, thus increasing the concentration of bioavailable Fe in surface seawater. Although the concentrations measured here are some of the highest reported in the literature, the true supply of Fe back to surface seawater will be controlled by processes such as organic complexation, scavenging and sinking by particles, remineralisation, and vertical transport, not measured in this study.
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physical speciation and solubility of iron from Baleen Whale faecal material
Marine Chemistry, 2017Co-Authors: Lavenia Ratnarajah, Delphine Lannuzel, Ashley T Townsend, Klaus M Meiners, Stephen Nicol, Ari S FriedlaenderAbstract:Abstract Primary productivity in large areas of the Southern Ocean is limited by the availability of a key micronutrient—iron (Fe). Recently it has been suggested that marine animals could play an important role in recycling Fe through their diet and subsequent defecation, however there is no information on the relative bioavailability of faecal Fe for uptake. The bioavailability of Fe in seawater is controlled by a number of complex interactions. The physical separation between the dissolved ( 0.2 μm) and particulate (> 0.2 μm) fractions is one common measure used to determine element bioavailability. Here, the size fractionation of Fe from 3 Whale faecal samples in 4 different size classes ( 0.2 μm, 0.2–10 μm, 10–60 μm and > 60 μm) was investigated, along with the leaching of particulate Fe over time. Although the total particulate fraction (> 0.2 μm, 5026–22,526 nmol L− 1) dominated the total Fe pool, the concentrations of dissolved Fe in Whale faecal samples (186–754 nmol L− 1 ) were three order of magnitude higher than published Southern Ocean surface seawater concentrations. Furthermore, results from the leaching experiment suggest that Fe is continually leached from faecal particles over an initial 12-hour period, thus increasing the concentration of bioavailable Fe in surface seawater. Although the concentrations measured here are some of the highest reported in the literature, the true supply of Fe back to surface seawater will be controlled by processes such as organic complexation , scavenging and sinking by particles, remineralisation , and vertical transport, not measured in this study.
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how Baleen Whales feed the biomechanics of engulfment and filtration
Annual Review of Marine Science, 2017Co-Authors: Jeremy A Goldbogen, John Calambokidis, Ari S Friedlaender, David E Cade, Jean Potvin, Paolo S Segre, Alexander J WerthAbstract:Baleen Whales are gigantic obligate filter feeders that exploit aggregations of small-bodied prey in littoral, epipelagic, and mesopelagic ecosystems. At the extreme of maximum body size observed among mammals, Baleen Whales exhibit a unique combination of high overall energetic demands and low mass-specific metabolic rates. As a result, most Baleen Whale species have evolved filter-feeding mechanisms and foraging strategies that take advantage of seasonally abundant yet patchily and ephemerally distributed prey resources. New methodologies consisting of multi-sensor tags, active acoustic prey mapping, and hydrodynamic modeling have revolutionized our ability to study the physiology and ecology of Baleen Whale feeding mechanisms. Here, we review the current state of the field by exploring several hypotheses that aim to explain how Baleen Whales feed. Despite significant advances, major questions remain about the processes that underlie these extreme feeding mechanisms, which enabled the evolution of the l...
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Baleen Whale calling behavior and response to anthropogenic sound
The Journal of the Acoustical Society of America, 2016Co-Authors: Alison K Stimpert, Selene Fregosi, Stacy L Deruiter, Erin A Falcone, John E Joseph, Tetyana Margolina, David Moretti, John Calambokidis, Ari S Friedlaender, Peter L TyackAbstract:Without a means of studying large Whales in a controlled experimental environment, less is understood about their sound production mechanisms than is understood about those of smaller odontocetes. To describe call production behavior in fin Whales, we used a recent technique that correlates fast-sampling accelerometer signals from tags with concurrently recorded acoustic signals to identify calls produced by the tagged animal. We tagged 18 fin Whales as part of the Southern California Behavioral Response Study (SOCAL BRS), of which four were confirmed to be calling. We were then able to describe their kinematic and social behavior in relation to call production. Behaviors associated with elevated call rates included shallow maximum dive depths, little body movement, and negative pitch in body orientation, similar to some other calling Baleen Whale species. These are the first descriptions of body orientation and dive depths at which fin Whales are most likely to call. We also describe calling responses (or lack thereof) from blue and fin Whales exposed to simulated mid-frequency active sonar. The call behavior characterizations presented here will help with predicting calling behavior from surface behavior, informing interpretation of passive acoustic data, and further investigating effects of anthropogenic sound on Baleen Whales.
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blue Whales respond to simulated mid frequency military sonar
Proceedings of The Royal Society B: Biological Sciences, 2013Co-Authors: Jeremy A Goldbogen, Stacy L Deruiter, John Calambokidis, Ari S Friedlaender, Brandon L Southall, Elliott L Hazen, Erin A FalconeAbstract:Mid-frequency military (1–10 kHz) sonars have been associated with lethal mass strandings of deep-diving toothed Whales, but the effects on endangered Baleen Whale species are virtually unknown. Here, we used controlled exposure experiments with simulated military sonar and other mid-frequency sounds to measure behavioural responses of tagged blue Whales (Balaenoptera musculus) in feeding areas within the Southern California Bight. Despite using source levels orders of magnitude below some operational military systems, our results demonstrate that mid-frequency sound can significantly affect blue Whale behaviour, especially during deep feeding modes. When a response occurred, behavioural changes varied widely from cessation of deep feeding to increased swimming speed and directed travel away from the sound source. The variability of these behavioural responses was largely influenced by a complex interaction of behavioural state, the type of mid-frequency sound and received sound level. Sonar-induced disruption of feeding and displacement from high-quality prey patches could have significant and previously undocumented impacts on Baleen Whale foraging ecology, individual fitness and population health.
