@article {58484, title = {Mid-frequency song and low-frequency calls of sei whales in the Falkland Islands}, journal = {Royal Society Open Science}, volume = {9}, year = {2022}, abstract = {

Although sei whales (Balaenoptera borealis) are distributed throughout the globe, their behaviour and vocal repertoire are poorly described. We used passive acoustic monitoring to describe the vocal behaviour of sei whales in the Falkland Islands, between December 2018 and April 2019. We isolated more than 2000 low-frequency calls for manual classification, of which 510 calls with high signal-to-noise ratio were quantitatively measured. Five categories of stereotyped call types in the 15\–230 Hz range were described, some with multiple subcategories. These included some similar to previously described calls (e.g. downsweeps), but others that were novel in acoustic structure and frequency band. In the mid-frequency range, we documented a highly stereotyped, hierarchically structured and rhythmically repetitive song display. Songs were arranged in phrases with a structure composed of repetitive sub- phrases, and a diverse variety of sounds in the 1\–5 kHz range. Singing commenced in late February, despite the presence of whales and calls since early December, and continued through April. These acoustic properties and behavioural characteristics indicate that this is likely a male breeding display similar to songs and singing of other balaenopterids. This is the first detailed description of a song display for sei whales, highlighting the importance of the Falkland Islands.

}, keywords = {Balaenoptera borealis, low-frequency calls, passive acoustic monitoring, singing behaviour, song display}, doi = {10.1098/rsos.220738}, author = {Salvatore Cerchio and Caroline R. Weir} } @article {58467, title = {Temporal occurrence of three blue whale populations in New Zealand waters from passive acoustic monitoring}, journal = {Journal of Mammalogy}, year = {2022}, abstract = {

Describing spatial and temporal occurrence patterns of wild animal populations is important for understanding their evolutionary trajectories, population connectivity, and ecological niche specialization, with relevance for effective management. Throughout the world, blue whales produce stereotyped songs that enable identification of separate acoustic populations. We harnessed continuous acoustic recordings from five hydrophones deployed in the South Taranaki Bight (STB) region of Aotearoa New Zealand from January 2016 to February 2018. We examined hourly presence of songs from three different blue whale populations to investigate their contrasting ecological use of New Zealand waters. The New Zealand song was detected year-round with a seasonal cycle in intensity (peak February\–July), demonstrating the importance of the region to the New Zealand population as both a foraging ground and potential breeding area. The Antarctic song was present in two distinct peaks each year (June\–July; September\–October) and predominantly at the offshore recording locations, suggesting northbound and southbound migration between feeding and wintering grounds. The Australian song was only detected during a 10-day period in January 2017, implying a rare vagrant occurrence. We therefore infer that the STB region is the primary niche of the New Zealand population, a migratory corridor for the Antarctic population, and outside the typical range of the Australian population.

}, keywords = {bioacoustics, blue whale, distribution, ecology, marine mammals, New Zealand, passive acoustic monitoring, populations, vocalizations}, doi = {10.1093/jmammal/gyac106}, url = {https://doi.org/10.1093/jmammal/gyac106}, author = {Dawn R Barlow and Holger Klinck and Dimitri Ponirakis and Mattea Holt Colberg and Leigh G. Torres} } @article {58254, title = {Fin whale acoustic presence and song characteristics in seas to the southwest of Portugal}, journal = {The Journal of the Acoustical Society of America}, volume = {147}, year = {2020}, month = {Jan-04-2020}, pages = {2235 - 2249}, abstract = {

Fin whales were once abundant in the seas to the southwest of Portugal, but whaling activities decreased their numbers considerably. Acoustic data from ocean bottom seismometers provide an opportunity to detect fin whales from their notes, data that would otherwise be logistically challenging and expensive to obtain. Based on inter-note interval and frequency bandwidth, two acoustic patterns produced by fin whales were detected in the study area: pattern 1, described from fin whales in the Mediterranean Sea, and pattern 2, associated with fin whales from the northeast North Atlantic Ocean (NENA). NENA fin whales travel into the western Mediterranean Sea, but the Mediterranean population has not been documented to travel regularly into the NENA. In this study, 11\ months of acoustic data recorded southwest of Portugal in the NENA were used to characterize 20-Hz fin whale notes into these patterns. Pattern 2 was the most common and occurred mostly in November\–January. Pattern 1 occurred less frequently and mostly in September\–December, February and April, which suggested a limited excursion of whales from the Mediterranean Sea. There were also occasions when the two patterns were recorded simultaneously. Results suggest that fin whales from the NENA and Mediterranean Sea might mix in the area during part of the year.

}, issn = {0001-4966}, doi = {10.1121/10.0001066}, url = {http://asa.scitation.org/doi/10.1121/10.0001066}, author = {Pereira, Andreia and Harris, Danielle and Tyack, Peter and Matias, Luis} } @article {53537, title = {Song variation of the South Eastern Indian Ocean pygmy blue whale population in the Perth Canyon, Western Australia}, journal = {PLOS ONE}, volume = {14}, year = {2019}, month = {Oct-01-2020}, pages = {e0208619}, abstract = {

Sea noise collected over 2003 to 2017 from the Perth Canyon, Western Australia was analysed for variation in the South Eastern Indian Ocean pygmy blue whale song structure. The primary song-types were: P3, a three unit phrase (I, II and III) repeated with an inter-song interval (ISI) of 170\–194 s; P2, a phrase consisting of only units II \& III repeated every 84\–96 s; and P1 with a phrase consisting of only unit II repeated every 45\–49 s. The different ISI values were approximate multiples of each other within a season. When comparing data from each season, across seasons, the ISI value for each song increased significantly through time (all fits had p \<\< 0.001), at 0.30 s/Year (95\%CI 0.217\–0.383), 0.8 s/Year (95\%CI 0.655\–1.025) and 1.73 s/Year (95\%CI 1.264\–2.196) for the P1, P2 and P3 songs respectively. The proportions of each song-type averaged at 21.5, 24.2 and 56\% for P1, P2 and P3 occurrence respectively and these ratios could vary by up to \± 8\% (95\% CI) amongst years. On some occasions animals changed the P3 ISI to be significantly shorter (120\–160 s) or longer (220\–280 s). Hybrid song patterns occurred where animals combined multiple phrase types into a repeated song. In recent years whales introduced further complexity by splitting song units. This variability of song-type and proportions implies abundance measure for this whale sub population based on song detection needs to factor in trends in song variability to make data comparable between seasons. Further, such variability in song production by a sub population of pygmy blue whales raises questions as to the stability of the song types that are used to delineate populations. The high level of song variability may be driven by an increasing number of background whale callers creating \‘noise\’ and so forcing animals to alter song in order to \‘stand out\’ amongst the crowd.

}, doi = {10.1371/journal.pone.0208619}, url = {http://dx.plos.org/10.1371/journal.pone.0208619}, author = {Jolliffe, Capri D. and McCauley, Robert D. and Gavrilov, Alexander N. and Jenner, K. Curt S. and Jenner, Micheline-Nicole M. and Duncan, Alec J.}, editor = {Matsumoto, Haru} } @article {53521, title = {Two unit analysis of Sri Lankan pygmy blue whale song over a decade}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-12-2018}, pages = {3618 - 3626}, abstract = {

Sri Lankan pygmy blue whale song consists of three repeated units: (1) low frequency pulsive unit, (2) frequency modulated (FM) upsweep, and (3) long tonal downsweep. The Unit 2 FM unit has up to three visible upsweeps with energy concentrated at approximately 40, 50, and 60\ Hz, while the Unit 3 (\∼100\ Hz) tonal downsweep is the most distinct unit lasting 20\–30\ s. Spectral characteristics of the Units 2 and 3 song elements, along with ocean sound levels, were analyzed in the Indian Ocean from 2002 to 2013. The peak frequency of the tonal Unit 3 calls decreased from approximately 106.5 to 100.7\ Hz over a decade corresponding to a 5.4\% decrease. Over the same time period, the frequency content of the Unit 2 upsweeps did not change as dramatically with only a 3.1\% change. Ambient sound levels in the vocalization bands did not exhibit equivalent patterns in amplitude trends. Analysis showed no increase in the ambient sound or compensated peak amplitude levels of the tonal downsweeps, eliminating the presence of a Lombard effect. Here it is proposed that each song unit may convey different information and thus may be responding to different selective pressures.

}, issn = {0001-4966}, doi = {10.1121/1.5084269}, url = {http://asa.scitation.org/doi/10.1121/1.5084269}, author = {Jennifer L. Miksis-Olds and Nieukirk, Sharon L. and Danielle V. Harris} } @mastersthesis {53433, title = {Investigation of fin whales using ocean-bottom recordings}, year = {2018}, school = {UNIVERSIDADE DE LISBOA}, type = {PhD}, address = {Lisbon}, abstract = {

Instruments used for seismic monitoring (OBS) have been recording baleen whales along with the target data. These long-term datasets provide valuable information for the study of large cetaceans that would otherwise be difficult to obtain due to economic and logistic reasons. Fin whales are classified as \‘Endangered\’ species and therefore knowledge about population size and spatial and temporal distribution patterns is essential for good management strategies. In Portugal, sightings of fin whales off mainland waters are rare and are insufficient to assess any kind of trend. In this context, seismic datasets may become one of the primary sources of information on a year-round basis. The general aim of this thesis was to demonstrate the use of acoustic datasets, collected for non-biological focussed studies, such as seismic data, to study fin whales. Between September 2007 and August 2008 a network of 24 OBS was deployed off southwest Portugal with the main aim to obtain data to study the microseismicity originating from potential tsunami sources. During this time fin whale sounds were also recorded. The main acoustic signal produced by fin whales used in this thesis was the 20-Hz call. A detection process to detect the 20-Hz call was developed (Chapter 2) and the resulting dataset of automatic detections was used to: 1) estimate a relative location, i.e. a range from the recording instrument, of the automatic detections with the single-station method and develop a classification scheme that help deciding if a detection was from a 20-Hz call and if the range estimates were inside the critical area of the single station (Chapter 3); 2) characterize the 20-Hz call and assess the existence of different acoustic groups (Chapter 4); 3) obtain an average fin whale density and abundance (Chapter 5); and 4) assess the impact of acoustic interference on the 20-Hz call and infer about the depth of the calling fin whale (Chapter 6). This thesis showed how OBS data can be used in different types of studies about fin whales and provide valuable information for cetacean conservation.

}, keywords = {bioacoustics, cetacean, fin whale, Ocean-bottom seismometer (OBS), wildlife conservartion}, author = {Andreia Filipa da Pereira} } @article {53357, title = {Long-Term and Seasonal Changes of Large Whale Call Frequency in the Southern Indian Ocean}, journal = {Journal of Geophysical Research: Oceans}, year = {2018}, month = {Mar-11-2020}, abstract = {

In the past decades, in the context of a changing ocean submitted to an increasing human activity, a progressive decrease in the frequencies (pitch) of blue whale vocalizations has been observed worldwide. Its causes, of natural or anthropogenic nature, are still unclear. Based on 7 years of continuous acoustic recordings at widespread sites in the southern Indian Ocean, we show that this observation stands for five populations of large whales. The frequency of selected units of vocalizations of fin, Antarctic, and pygmy blue whales has steadily decreased at a rate of a few tenths of hertz per year since 2002. In addition to this interannual frequency decrease, blue whale vocalizations display seasonal frequency shifts. We show that these intra-annual shifts correlate with seasonal changes in the ambient noise near their call frequency. This ambient noise level, in turn, shows a strong correlation with the seasonal presence of icebergs, which are one of the main sources of oceanic noise in the Southern Hemisphere. Although cause-and-effect relationships are difficult to ascertain, wide-ranging changes in the acoustic environment seem to have a strong impact on the vocal behavior of large baleen whales. Seasonal frequency shifts may be due to short-term changes in the ambient noise, and the interannual frequency decline to long-term changes in the acoustic properties of the ocean and/or in postwhaling changes in whale abundances.

}, doi = {10.1029/2018JC014352}, url = {http://doi.wiley.com/10.1029/2018JC014352}, author = {Leroy, Emmanuelle C. and Royer, Jean-Yves and Bonnel, Julien and Samaran, Flore} } @article {53329, title = {Environmental evidence for a pygmy blue whale aggregation area in the Subtropical Convergence Zone south of Australia}, journal = {Marine Mammal Science}, volume = {34}, year = {2018}, month = {Jan-10-2018}, pages = {901 - 923}, abstract = {

The importance of the Subtropical Convergence Zone south of Australia as a feeding area to the pygmy blue whale of the eastern Indian Ocean was investigated to better understand migration patterns and habitat use. A combination of satellite tagging studies during 2003\–2005 and acoustic and visual surveys during the austral summer of 2013 confirmed the presence of pygmy blue whales in the Subtropical Convergence Zone and provided evidence for feeding throughout the region. Of the 67 pygmy blue whales acoustically detected, many were localized in proximity to sea surface temperature fronts and high chlorophyll concentrations, which could be a behavioral strategy to attract conspecifics to good feeding sites. Aggregations of up to four pygmy blue whales, along with decreased call rates during the day, may suggest feeding despite no direct observations of pygmy blue whales consuming euphausiids. The oceanographic features present throughout the Subtropical Convergence Zone continue to create an environment productive enough to support the world\&$\#$39;s largest living mammals during their migratory foraging movements between the Southern Ocean and Indonesia.

}, doi = {10.1111/mms.v34.410.1111/mms.12494}, url = {http://doi.wiley.com/10.1111/mms.v34.4}, author = {Garcia-Rojas, Maria I. and Jenner, K. Curt S. and Gill, Peter C. and Jenner, Micheline-Nicole M. and Sutton, Alicia L. and McCauley, Robert D.} } @article {53297, title = {Detection and classification of whales calls using band-limited energy detection and transfer learning}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1769 - 1769}, abstract = {

The Monterey Bay Aquarium Research Institute has been recording since July 2015 almost continuously at the Monterey Accelerated Research System (MARS) cabled observatory in Monterey Bay, California, USA. This long-term recording contains thousands of whale calls to help further our understanding of interannual, seasonal, and diel patterns. Here we report on our highly accurate detection and classification method developed to classify blue whale A, B, and D calls and Fin whale 20 Hz pulses. The foundation of the method is a computationally efficient and tuned decimation filter to convert the broadband hydrophone 128 kHz signal to 2 kHz which preserves the low-frequency signal and avoids any high-frequency aliasing. Detection is done using a band-limited-energy-detection filter to find potential calls in the decimated data. Spectrograms are then generated for potential calls and enhanced with local image normalization followed by smoothing by convolving in either time or frequency. Classification is done using the Google Inception v3 model with a transfer learning method. Overall, false positive rates are very low despite variability in whale call shape and background noise.

}, issn = {0001-4966}, doi = {10.1121/1.5067825}, url = {http://asa.scitation.org/doi/10.1121/1.5067825}, author = {Cline, Danelle E. and Ryan, John P.} } @article {53103, title = {On the reliability of acoustic annotations and automatic detections of Antarctic blue whale calls under different acoustic conditions}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-08-2018}, pages = {740 - 754}, abstract = {

Evaluation of the performance of computer-based algorithms to automatically detect mammalian vocalizations often relies on comparisons between detector outputs and a reference data set, generally obtained by manual annotation of acoustic recordings. To explore the reproducibility of these annotations, inter- and intra-analyst variability in manually annotated Antarctic blue whale (ABW) Z-calls are investigated by two analysts in acoustic data from two ocean basins representing different scenarios in terms of call abundance and background noise. Manual annotations exhibit strong inter- and intra-analyst variability, with less than 50\% agreement between analysts. This variability is mainly caused by the difficulty of reliably and reproducibly distinguishing single calls in an ABW chorus made of overlaying distant calls. Furthermore, the performance of two automated detectors, based on spectrogram correlation or subspace-detection strategy, is evaluated by comparing detector output to a \“conservative\” manually annotated reference data set, which comprises only analysts\&$\#$39; matching events. This study highlights the need for a standardized approach for human annotations and automatic detections, including a quantitative description of their performance, to improve the comparability of acoustic data, which is particularly relevant in the context of collaborative approaches in collecting and analyzing large passive acoustic data sets.

}, issn = {0001-4966}, doi = {10.1121/1.5049803}, url = {http://asa.scitation.org/doi/10.1121/1.5049803}, author = {Leroy, Emmanuelle C. and Thomisch, Karolin and Royer, Jean-Yves and Boebel, Olaf and Van Opzeeland, Ilse} } @article {53064, title = {Context-dependent variability in blue whale acoustic behaviour}, journal = {Royal Society Open Science}, volume = {5}, year = {2018}, abstract = {

Acoustic communication is an important aspect of reproductive, foraging and social behaviours for many marine species. Northeast Pacific blue whales (Balaenoptera musculus) produce three different call types\—A, B and D calls. All may be produced as singular calls, but A and B calls also occur in phrases to form songs. To evaluate the behavioural context of singular call and phrase production in blue whales, the acoustic and dive profile data from tags deployed on individuals off southern California were assessed using generalized estimating equations. Only 22\% of all deployments contained sounds attributed to the tagged animal. A larger proportion of tagged animals were female (47\%) than male (13\%), with 40\% of unknown sex. Fifty per cent of tags deployed on males contained sounds attributed to the tagged whale, while only a few (5\%) deployed on females did. Most calls were produced at shallow depths (less than 30\ m). Repetitive phrasing (singing) and production of singular calls were most common during shallow, non-lunging dives, with the latter also common during surface behaviour. Higher sound production rates occurred during autumn than summer and they varied with time-of-day: singular call rates were higher at dawn and dusk, while phrase production rates were highest at dusk and night.

}, keywords = {acoustic communication, Balaenoptera musculus, behavioural context, blue whale, song}, doi = {10.1098/rsos.180241}, url = {http://rsos.royalsocietypublishing.org/lookup/doi/10.1098/rsos.180241https://syndication.highwire.org/content/doi/10.1098/rsos.180241}, author = {Lewis, Leah A. and Calambokidis, John and Stimpert, Alison K. and Fahlbusch, James and Friedlaender, Ari S. and McKenna, Megan F. and Mesnick, Sarah L. and Southall, Brandon L. and Szesciorka, Angela R. and {\v S}irovi{\'c}, Ana} } @mastersthesis {52812, title = {Impacts of Ambient Noise on Minke Whale (Balaenoptera acutorostrata) Habitat Use and Behavior}, year = {2018}, pages = {171}, type = {phd}, abstract = {

This study examines the soundscape of minke whale habitat in the Scottish Inner Hebrides around the islands of Mull, Coll and Muck and near the Ardnamurchan Peninsula of the Scottish mainland. To compare the soundscape with minke whale presence and behavior, acoustic recordings were paired with behavior and respiration data. Acoustic recordings were taken using a Soundtrap 300, deployed from a whale watching vessel. Data was taken from June - September 2016. The soundscape was analyzed by comparing power spectral density averaged into octave bands (center frequencies from 16 Hz \– 128 kHz). The soundscape of the region is ephemeral, with some locations having very different acoustic patterns depending on transient animal and human activity. Humans contribute to the soundscape through movement of small ships and dredging. Notable biological contributors to the soundscape include dolphins and snapping shrimp. Outside the island of Coll is quieter at mid-frequencies (2-8 kHz octave bands). Inside Coll is quieter at frequencies in the 16-128 kHz octave bands. Ardmore point, in the Sound of Mull, is louder for most frequencies. These differences create a potential way for animals to navigate or orient based on sound. Observed minke whale behaviors were categorized into behavior states to create a behavior budget. Minke whales in this area spend 56\% of their daytime feeding, 7\% traveling and 39\% in other activities. The average inter-breath interval for minke whales in this study was 60.7s. Minke presence and behavior were compared with sound levels in 1/3rd octave bands using generalized linear models. Minke whale presence and behavior both correlate with changes in the Soundscape. Minke whales are less likely to be seen with higher levels of low (31 Hz) and high (25.4 kHz) frequency sound. Higher levels of sound at low (63 Hz) frequencies were associated with lower probability of minke whales feeding. Higher probability of minke whales feeding in higher levels of high (25.4 kHz) frequency sound may indicate that minke whales are optimizing that time which is spent in regions with higher levels of noise at these frequencies.

}, keywords = {acoustics, ambient noise, Balaenoptera acutorostrata, Behavior, biological sciences, Conservation biology, Environmental science, Health and environmental sciences, Minke, Pure sciences, Soundscape}, isbn = {9780355660500}, url = {https://search.proquest.com/docview/2020840628?accountid=15181}, author = {Roland, Adele} } @article {47323, title = {Estimation of minke whale abundance from an acoustic line transect survey of the Mariana Islands}, journal = {Marine Mammal Science}, year = {2017}, month = {Jan-03-2017}, abstract = {

The minke whale is one of the most abundant species of baleen whales worldwide, yet is rarely sighted in subtropical waters. In the North Pacific, they produce a dis- tinctive sound known as the \“boing,\” which can be used to acoustically localize indi- viduals. A vessel-based survey using both visual and passive acoustic monitoring was conducted during the spring of 2007 in a large (616,000 km 2 ) study area encom- passing the Mariana Islands. We applied line transect methods to data collected from a towed hydrophone array to estimate the abundance of calling minke whales in our study area. No minke whales were sighted, but there were hundreds of acoustic detections of boings. Computer algorithms were developed to localize calling minke whales from acoustic recordings, resulting in over 30 independent localizations, a six-fold increase over those estimated during the survey. The two best estimates of abundance of calling minke whales were determined to be 80 and 91 animals (0.13 and 0.15 animals per 1,000 km2, respectively; CV = 34\%). These are the first den- sity and abundance estimates for calling minke whales using towed hydrophone array surveys, and the first estimates for this species in the Mariana Islands region. These are considered minimum estimates of the true number of minke whales in the study area.

}, keywords = {Balaenoptera acutorostrata, density esti- mation, Mariana Islands, marine mammals., minke whale, Pacific, passive acoustics}, doi = {10.1111/mms.12397}, url = {http://doi.wiley.com/10.1111/mms.12397}, author = {Norris, Thomas F. and Dunleavy, Kerry J. and Yack, Tina M. and Ferguson, Elizabeth L.} } @article {16153, title = {Seasonal acoustic behavior of blue whales ( Balaenoptera musculus ) in the Gulf of California, Mexico}, journal = {Marine Mammal Science}, volume = {33}, year = {2017}, month = {Jan-01-2017}, pages = {206 - 218}, doi = {10.1111/mms.2017.33.issue-110.1111/mms.12362}, url = {http://doi.wiley.com/10.1111/mms.2017.33.issue-1}, author = {Paniagua-Mendoza, Aurora and Gendron, Diane and Romero-Vivas, Eduardo} } @article {16152, title = {Using calls as an indicator for Antarctic blue whale occurrence and distribution across the southwest Pacific and southeast Indian Oceans}, journal = {Marine Mammal Science}, volume = {33}, year = {2017}, month = {Jan-01-2017}, pages = {172 - 186}, doi = {10.1111/mms.2017.33.issue-110.1111/mms.12373}, url = {http://doi.wiley.com/10.1111/mms.2017.33.issue-1}, author = {Balcazar, Naysa E. and Klinck, Holger and Nieukirk, Sharon L. and Mellinger, David K. and Klinck, Karolin and Dziak, Robert P. and Rogers, Tracey L.} }