Sounds and source levels from bowhead whales off Pt. Barrow, Alaska

Cummings, William C.; Holliday, D. V.

doi:10.1121/1.395279

Cited by 65 publications

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“…when one whale ceased, another often began (Cummings and Holliday 1987). Such behaviour could be particularly beneficial for individuals that might not wish to advertise their presence, such as males competing for access to a receptive female, or females with calves seeking to avoid the attentions of an amorous male.…”

Section: Eavesdroppingmentioning

confidence: 99%

Acoustic behaviour of southern right whales in relation to numbers of whales present in Walker Bay, South Africa

Hofmeyer-Juritz

Best²

2011

African Journal of Marine Science

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Estimating numbers of whales present in an area from recorded call rates could be a useful conservation tool. We recorded southern right whale Eubalaena australis vocalisations and presence in Walker Bay on the south coast of South Africa. In all, 45 sessions with synchronous acoustic and visual data were analysed to determine call rates directly (overall call rate, OCR) and in relation to the number of whales sighted (call rate per whale, CPW) and number of groups sighted (call rate per group, CPG).The OCRs were examined in the presence of varying numbers of whales, using a loglinear model to investigate the dependence of the call rate on whale density. The number of whales present exerted a strong quadratic effect on the OCR, which peaked at around 15 whales and decreased to a low rate as whale presence approached a maximum, for all calls combined and for four of their constituent 13 call types: a quadratic trend was present to varying degrees among the remaining call types. Both quadratic and linear trends were absent when OCR was assessed against number of groups present, possibly because group size increased with increasing density of whales. A linear regression on the CPW and CPG suggested that there was a negative inverse relationship with the number of whales and groups present respectively. These findings are important in that, while they preclude the estimation of absolute numbers from call rates, they imply that under the conditions prevailing in Walker Bay, southern right whales were aware of the presence, arrival and departure of other animals in their vicinity and adjusted their vocal behaviour accordingly.Keywords: acoustics, call rates, Eubalaena australis, log-linear model, southern right whale, vocalisations, relative abundance IntroductionThe ability to locate and estimate the density and movement patterns of whales present in an area is an important prerequisite for many aspects of their 2 conservation, but such factors are often difficult to ascertain. Whales spend much of their time submerged, and may cover long distances daily. Visual sightings are severely hampered by rough weather conditions, and are almost impossible at night.Communication among individual cetaceans in the contexts of reproductive display, prey detection, predator avoidance and navigation, is primarily acoustic (Clark 1982, MacLennan and Simmonds 1992, Parks 2003a. Therefore, using biological sounds to detect whales (Mellinger et al. 2011) is suited both to the underwater medium and the properties of the calls. While this method can only detect vocalising individuals, acoustic detection of whales has several advantages over visual detection, as has been demonstrated for fin whales Balaenoptera physalus (McDonald and Fox 1999). It can be applied in remote situations and for extended periods of time (Clark et al. 2010, Mellinger et al. 2011, in situations where boat and aerial surveys would be impractical or expensive. Additionally, remote acoustic detection can cover a greater range than visual detection, can occur under...

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Section: Eavesdroppingmentioning

confidence: 99%

Acoustic behaviour of southern right whales in relation to numbers of whales present in Walker Bay, South Africa

Hofmeyer-Juritz

Best²

2011

African Journal of Marine Science

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“…Vocalizations are produced primarily in the low frequency range (see review in Richardson et al, 1995; see also Thompson et al, 1986Thompson et al, , 1992Cummings and Holliday, 1987;Crane and Lashkari, 1996;Stafford et al, 1999;Mellinger and Clarke, 2003). As low frequency sounds travel farther than high frequencies before attenuating, mysticetes appear to use low frequencies to communicate over long distances and thereby maintain pod cohesion when visual contact is obscured by large separations (Wursig, 1988).…”

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confidence: 99%

Discovery of a low frequency sound source in Mysticeti (baleen whales): Anatomical establishment of a vocal fold homolog

Reidenberg

Laitman

2007

The Anatomical Record

105

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The mechanism of mysticete (baleen whale) vocalization has remained a mystery. Vocal folds (true vocal ''cords''), the structures responsible for sound production in terrestrial mammals, were thought to be absent in whales. This study tests the hypothesis that the mysticete larynx possesses structures homologous to vocal folds and that they are capable of sound generation. Laryngeal anatomy was examined in 37 specimens representing 6 mysticete species. Results indicate the presence of a U-shaped fold (U-fold) in the lumen of the larynx. The U-fold is supported by arytenoid cartilages, controlled by skeletal muscles innervated by the recurrent laryngeal nerve, is adjacent to a diverticulum (laryngeal sac) covered with mucosa innervated by the superior laryngeal nerve, and contains a ligament-conditions that also define the vocal folds of terrestrial mammals and, therefore, supports homology. Unlike the vocal folds of terrestrial mammals, which are perpendicular to airflow, the mysticete U-fold is oriented parallel to airflow. U-fold adduction/abduction and elevation/depression may control airflow, and vibration of its edges may generate sounds. The walls of the laryngeal sac can expand and contract, may serve as a resonant space, and may also propagate vibrations generated by movements of the supporting arytenoid cartilages. The extensive musculature surrounding the laryngeal sac may enable rapid and forceful expulsion of air from the lumen of the sac into other respiratory spaces, or maintain a constant sac volume despite the effects of ambient pressure (e.g., changes during diving or ascent). The size and complexity of the mysticete larynx indicates an organ with multiple functions, including protection during breathing/swallowing, regulation of airflow and pressures in the respiratory spaces, and sound generation. The presence of a vocal fold homolog offers a new insight into both the mechanism of sound generation by mysticetes and the divergent evolution of odontocete and mysticete cetaceans. Anat Rec, 290:745-759, 2007. 2007 Wiley-Liss, Inc.

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“…Intense calls (up to 170 -180 dB in the 100 -1000 Hz band) are used for communication and navigation (Cummings and Holliday, 1987;Würsig and Clark, 1993). Most calls during spring migration are lowfrequency sweeps or 'J whoops,' evidently used for longrange communication and herd navigation (Clark and Johnson, 1984;Clark, 1991).…”

Section: Communicationmentioning

confidence: 99%

Natural History and Conservation of the Greenland Whale, or Bowhead, in the Northwest Atlantic

Finley¹

2001

ARCTIC

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ABSTRACT. One of the longest-living mammals, the Greenland whale or bowhead (Balaena mysticetus) is specialized to filter small crustaceans, especially Calanus copepods, from barren Arctic seas. Brought to near extinction by commercial whaling, the North Atlantic 'meta-population' remains at less than 5% of its former abundance, and none of its three constituent stocks has shown demonstrable recovery during the last century. Two of these stocks, the Baffin Bay and Hudson Bay populations, occur in coastal waters of the Eastern Canadian Arctic during summer. Each of these two stocks numbers in the low hundreds and exists in isolated groups segregated by age and sex, showing strong fidelity to essential habitats. A skewed age distribution, predation by killer whales (Orcinus orca), hunting, net entanglement, tourism, climate change, habitat loss, and inbreeding suppression are some of the factors that may affect the bowhead's recovery. We need local and historical knowledge to understand the bowhead's natural history. Together with scientific data, such knowledge is also useful in evaluating the status of the species and prescribing a management plan. A recovery plan must employ the precautionary principle, both within the international 'meta-population' context and at the sub-population level; it must take a historical view and seek to protect abandoned habitats. Canada has conducted whaling activities that violate international agreements and diminish the effectiveness of the International Whaling Commission.Key words: Greenland whale, bowhead whale, Balaena mysticetus, biology, conservation, management, traditional knowledge RÉSUMÉ. La baleine boréale ou baleine franche (Balaena mysticetus), l'un des mammifères qui vit le plus longtemps, est spécialisée pour filtrer les petits crustacés, des copépodes Calanus pour la plupart, vivant dans les mers arctiques peu peuplées. Amenée au bord de l'extinction par la chasse commerciale à la baleine, la «métapopulation» de l'Atlantique Nord se maintient à moins de 5 p. cent de son abondance passée, et aucun des trois stocks qui la composent n'a montré un rétablissement ferme au cours du siècle dernier. Deux de ces stocks, la population de la baie de Baffin et celle de la baie d'Hudson, se trouvent en été dans les eaux côtières de l'Arctique canadien oriental. Chacun d'eux comprend quelques centaines d'individus, répartis en groupes isolés selon l'âge et le sexe, qui démontrent une fidélité marquée pour les habitats essentiels à leur survie. Une asymétrie de la distribution par âge, la prédation par les épaulards (Orcinus orca), la chasse, l'enchevêtrement dans les filets, le tourisme, le changement climatique, la perte d'habitat et la dépression consanguine sont au nombre des facteurs qui pourraient influencer le rétablissement de l'espèce. Le savoir local et le savoir historique sont tous deux nécessaires pour comprendre l'évolution naturelle de la baleine boréale. Couplés aux données scientifiques, ces savoirs sont en outre utiles dans l'évaluation de l'état de l'espèce ...

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Sounds and source levels from bowhead whales off Pt. Barrow, Alaska

Cited by 65 publications

References 0 publications

Acoustic behaviour of southern right whales in relation to numbers of whales present in Walker Bay, South Africa

Acoustic behaviour of southern right whales in relation to numbers of whales present in Walker Bay, South Africa

Discovery of a low frequency sound source in Mysticeti (baleen whales): Anatomical establishment of a vocal fold homolog

Natural History and Conservation of the Greenland Whale, or Bowhead, in the Northwest Atlantic

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