scholarly journals Calling under pressure: short-finned pilot whales make social calls during deep foraging dives

2011 ◽  
Vol 278 (1721) ◽  
pp. 3017-3025 ◽  
Author(s):  
Frants H. Jensen ◽  
Jacobo Marrero Perez ◽  
Mark Johnson ◽  
Natacha Aguilar Soto ◽  
Peter T. Madsen
Keyword(s):  
Sound Production ◽  
Energy Content ◽  
Ambient Pressure ◽  
Pilot Whale ◽  
Communication Signals ◽  
Deep Diving ◽  
Social Species ◽  
Air Supply ◽  
Social Calls ◽  
Pilot Whales

Toothed whales rely on sound to echolocate prey and communicate with conspecifics, but little is known about how extreme pressure affects pneumatic sound production in deep-diving species with a limited air supply. The short-finned pilot whale ( Globicephala macrorhynchus ) is a highly social species among the deep-diving toothed whales, in which individuals socialize at the surface but leave their social group in pursuit of prey at depths of up to 1000 m. To investigate if these animals communicate acoustically at depth and test whether hydrostatic pressure affects communication signals, acoustic DTAGs logging sound, depth and orientation were attached to 12 pilot whales. Tagged whales produced tonal calls during deep foraging dives at depths of up to 800 m. Mean call output and duration decreased with depth despite the increased distance to conspecifics at the surface. This shows that the energy content of calls is lower at depths where lungs are collapsed and where the air volume available for sound generation is limited by ambient pressure. Frequency content was unaffected, providing a possible cue for group or species identification of diving whales. Social calls may be important to maintain social ties for foraging animals, but may be impacted adversely by vessel noise.

scholarly journals Deep-diving pilot whales make cheap, but powerful, echolocation clicks with 50 µL of air

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ilias Foskolos ◽  
Natacha Aguilar de Soto ◽  
Peter Teglberg Madsen ◽  
Mark Johnson
Keyword(s):  
Deep Sea ◽  
Sound Production ◽  
Metabolic Cost ◽  
Aquatic Habitats ◽  
Field Metabolic Rate ◽  
Deep Diving ◽  
Top Predators ◽  
Sensory Channel ◽  
Pilot Whales ◽  
Boyle’S Law

Abstract Echolocating toothed whales produce powerful clicks pneumatically to detect prey in the deep sea where this long-range sensory channel makes them formidable top predators. However, air supplies for sound production compress with depth following Boyle’s law suggesting that deep-diving whales must use very small air volumes per echolocation click to facilitate continuous sensory flow in foraging dives. Here we test this hypothesis by analysing click-induced acoustic resonances in the nasal air sacs, recorded by biologging tags. Using 27000 clicks from 102 dives of 23 tagged pilot whales (Globicephala macrorhynchus), we show that click production requires only 50 µL of air/click at 500 m depth increasing gradually to 100 µL at 1000 m. With such small air volumes, the metabolic cost of sound production is on the order of 40 J per dive which is a negligible fraction of the field metabolic rate. Nonetheless, whales must make frequent pauses in echolocation to recycle air between nasal sacs. Thus, frugal use of air and periodic recycling of very limited air volumes enable pilot whales, and likely other toothed whales, to echolocate cheaply and almost continuously throughout foraging dives, providing them with a strong sensory advantage in diverse aquatic habitats.

Sperm whale sound production studied with ultrasound time/depth-recording tags

2002 ◽  
Vol 205 (13) ◽  
pp. 1899-1906 ◽  
Author(s):  
P. T. Madsen ◽  
R. Payne ◽  
N. U. Kristiansen ◽  
M. Wahlberg ◽  
I. Kerr ◽  
...  
Keyword(s):  
Sound Production ◽  
Ambient Pressure ◽  
Sperm Whale ◽  
Sound Pulse ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Hydrostatic Reduction ◽  
Deep Diving ◽  
Air Volume ◽  
Depth Recording

SUMMARYDelphinoids (Delphinidae, Odontoceti) produce tonal sounds and clicks by forcing pressurized air past phonic lips in the nasal complex. It has been proposed that homologous, hypertrophied nasal structures in the deep-diving sperm whale (Physeter macrocephalus) (Physeteridae, Odontoceti) are dedicated to the production of clicks. However, air volumes in diving mammals are reduced with increasing ambient pressure, which seems likely to influence pneumatic sound production at depth. To study sperm whale sound production at depth, we attached ultrasound time/depth-recording tags to sperm whales by means of a pole and suction cup. We demonstrate that sperm whale click production in terms of output and frequency content is unaffected by hydrostatic reduction in available air volume down to less than 2% of the initial air volume in the nasal complex. We present evidence suggesting that the sound-generating mechanism has a bimodal function, allowing for the production of clicks suited for biosonar and clicks more suited for communication. Shared click features suggest that sound production in sperm whales is based on the same fundamental biomechanics as in smaller odontocetes and that the nasal complexes are therefore not only anatomically but also functionally homologous in generating the initial sound pulse.

scholarly journals Love-iathan, the meat-whale and hidden people: ordering Faroese pilot whaling

2016 ◽  
Vol 23 (1) ◽  
pp. 26 ◽  
Author(s):  
Benedict E. Singleton
Keyword(s):  
News Item ◽  
Faroe Islands ◽  
Political Ontology ◽  
Pilot Whale ◽  
Environmental Dispute ◽  
Pilot Whales ◽  
Ocean Environment

A key question in any environmental dispute is the nature of what is under discussion. 'Cosmopolitics' – political battles over the form of reality – are a feature of many environmental clashes. This article focuses on one such clash: during the summer of 2014, grindadráp – the iconic practice of driving pilot whales for meat – was the big news item in the Faroe Islands. More accurately, a conservation campaign by the controversial group Sea Shepherd Conservation Society (SSCS), Operation Grindstop 2014, garnered most attention. Aiming to stop or at least disrupt the 'barbaric' and 'sadistic' grindadráp, SSCS were involved in several confrontations with Faroese authorities and publicly engaged with Faroese pro-whaling advocates in several discussions that were seemingly fruitless. Based on 3 months fieldwork during the campaign, this article describes a 'political ontology' of Grindstop 2014. What emerged was a 'hybrid' born of a clash between two fundamentally dissonant systems of ordering, which structured and were reinforced by various practices, both discursive and material. Activists on both sides were engaged in a cosmopolitical struggle to decisively enact their orderings, creating alternative stories of whales, Faroese whaling, the ocean environment and modernity. The aim is to understand what happened when these orderings met. This article argues that throughout the summer these two orderings moved apart, consequently hiding the diversity of opinion and discussion within Faroese society around grindadráp. As such, alternative orderings of grindadráp were suppressed, notably those voiced by Faroese activists arguing that the practice should cease because of the high levels of toxins in pilot whale meat.Key words: Faroe Islands, whaling, political ontology, cosmopolitics

Electrophoretic differentiation among local populations of the long-finned pilot whale, Globicephala melaena, at the Faroe Islands

1988 ◽  
Vol 66 (8) ◽  
pp. 1884-1892 ◽  
Author(s):  
Liselotte Wesley Andersen
Keyword(s):  
Reproductive Isolation ◽  
Muscle Tissue ◽  
Gel Electrophoresis ◽  
Faroe Islands ◽  
Starch Gel Electrophoresis ◽  
Pilot Whale ◽  
Local Populations ◽  
Starch Gel ◽  
Pilot Whales ◽  
Polymorphic Enzymes

Enzyme variation within and between nine schools of long-finned pilot whales, Globicephala melaena, caught at the Faroe Islands, was examined by starch gel electrophoresis. Twenty-seven enzymes were investigated, representing 41 loci, of which three were polymorphic. The polymorphic enzymes were analyzed in either liver or muscle tissue from 628 specimens. No heterogeneity within the schools was observed, while significant differences in allele frequencies between schools were detected by a multilocus G-test. This result indicated some degree of reproductive isolation.

scholarly journals Species can base their impression of themselves on the number of sensory neurons they have and their IUCN level

2021 ◽  
Author(s):  
aaron goetz
Keyword(s):  
Emotional Disturbance ◽  
Sensory Neurons ◽  
Killer Whale ◽  
Anthropogenic Influence ◽  
Aquatic Species ◽  
Pilot Whale ◽  
Terrestrial Species ◽  
Western Gorilla ◽  
Pilot Whales

Abstract Humans have the most sensory neurons of any terrestrial species, 18.83B, with more than twice as many as the runner up western gorilla. There are three aquatic species with more than humans and seven more with more than the western gorilla. The killer whale with more than twice as many as humans, long-finned and short-finned pilot whale with a little less than twice humans. With that many sensory neurons it would be assumed that those would be the species with the most emotional disturbance from anthropogenic influence. There is no data on killer whale endangerment, and both long and short finned pilot whales are LC, ranking them 23rd and 24th most disturbed species. It is important for us to consider what the species means to them in evaluating what species we should care about, it would be beneficial to base that on what species care about themselves the most.

Demographic parameters of a free‐ranging deep‐diving cetacean, the long‐finned pilot whale

2020 ◽  
Author(s):  
Philippe Verborgh ◽  
Pauline Gauffier ◽  
Ruth Esteban ◽  
Renaud de Stephanis
Keyword(s):  
Demographic Parameters ◽  
Pilot Whale ◽  
Deep Diving ◽  
Free Ranging

Physiological responses of king penguins during simulated diving to 136 m depth

1999 ◽  
Vol 202 (20) ◽  
pp. 2819-2822 ◽  
Author(s):  
P.J. Ponganis ◽  
G.L. Kooyman ◽  
R. van Dam ◽  
Y. LeMaho
Keyword(s):  
Ambient Pressure ◽  
Physiological Responses ◽  
Bubble Formation ◽  
Breath Holding ◽  
Available N ◽  
Respiratory Volume ◽  
Deep Diving ◽  
Total Body ◽  
Hb Concentration

To evaluate blood N(2) uptake and the role of the respiratory volume (air sacs/lungs) as a N(2) and O(2) reservoir in deep-diving penguins, diving respiratory volume (Vdr), heart rate (fh), venous P(N)(sum), blood volume (V(b)) and hemoglobin (Hb) concentration were measured in king penguins (Aptenodytes patagonicus) during forced submersions and compressions equivalent to depths up to 136 m. Vdr was 69+/−18 ml kg(−)(1) (mean +/− s.d.) in 62 submersions ranging from 4.4 atmospheres absolute (ATA; 1 ATA=101 kPa) (34 m) to 14.6 ATA (136 m). Submersion fh averaged 30+/−7 beats min(−)(1) (N=18), approximately 20 % of pre- and post-submersion values. Venous P(N)(sum) values during and after submersions as deep as 11.2 ATA (102 m) were all less than 2.8 atmospheres N(2) (283 kPa) above ambient pressure, a previously measured threshold for symptomatic bubble formation. Mean V(b) was 83+/−8 ml kg(−)(1) (N=6); [Hb] was 17.6+/−0.7 g dl(−)(1) (N=7). On a mass-specific basis, mean Vdr, and therefore total available N(2), is 41 % of that in shallow-diving penguin species. Total body O(2) stores, calculated from measured Vdr, V(b), [Hb], muscle mass and myoglobin concentration, are 45 ml kg(−)(1), with 23 % in the respiratory system. This small respiratory fraction in comparison with that in shallow-diving penguins suggests a lesser reliance on the respiratory oxygen store for extended breath-holding and also a reduced uptake of nitrogen at depth.

Social structure of long-finned pilot whales (Globicephala melas) off northern Cape Breton Island, Nova Scotia

Behaviour ◽  
2017 ◽  
Vol 154 (5) ◽  
pp. 509-540 ◽  
Author(s):  
J.F. Augusto ◽  
T.R. Frasier ◽  
H. Whitehead
Keyword(s):  
Social Structure ◽  
Pilot Whale ◽  
Detailed Model ◽  
Cape Breton Island ◽  
Long Term Stability ◽  
Cape Breton ◽  
Northern Cape ◽  
Pilot Whales ◽  
Average Size ◽  
Social Units

Cetacean social structures include fluid and stable elements. Long-finned pilot whales (Globicephala melas) live in units that interact forming labile groups. In this study conducted off Cape Breton Island, between 1998–2011, we confirm unit membership predicts associations between individuals. We determine how units are structured and interact. We delineated 21 nearly-stable social units, with an average 7 members. For units where multiple individuals are sexed, both sexes are present. Most units showed long-term stability, while one showed evidence of splitting. Three units shared individuals with the largest unit (K, average size = 29). Splitting is likely triggered by size and difficulties maintaining associations between all individuals. Pilot whales face many pressures driving sociality at a range of temporal and social scales producing a multilevel society. While we have produced a more detailed model of long-finned pilot whale social structure, there are still unanswered questions, particularly whether units are strict matrilines.

scholarly journals Ecological niches of three teuthophageous odontocetes in the northwestern Mediterranean Sea

Ocean Science ◽  
2008 ◽  
Vol 4 (1) ◽  
pp. 49-59 ◽  
Author(s):  
E. Praca ◽  
A. Gannier
Keyword(s):  
Mediterranean Sea ◽  
Sperm Whale ◽  
Ecological Niches ◽  
Sperm Whales ◽  
Ligurian Sea ◽  
Data Set ◽  
Pilot Whale ◽  
Northwestern Mediterranean Sea ◽  
Pilot Whales ◽  
Northwestern Mediterranean

Abstract. In the northwestern Mediterranean Sea, sperm whales, pilot whales and Risso's dolphins prey exclusively or preferentially on cephalopods. In order to evaluate their competition, we modelled their habitat suitability with the Ecological Niche Factor Analysis (ENFA) and compared their ecological niches using a discriminant analysis. We used a long term (1995–2005) small boat data set, with visual and acoustic (sperm whale) detections. Risso's dolphin had the shallowest and the more spatially restricted principal habitat, mainly located on the upper part of the continental slope (640 m mean depth). With a wider principal habitat, at 1750 m depth in average, the sperm whale used a deeper part of the slope as well as the closest offshore waters. Finally, the pilot whale has the most oceanic habitat (2500 m mean depth) mainly located in the central Ligurian Sea and Provençal basin. Therefore, potential competition for food between these species may be reduced by the differentiation of their habitats.

scholarly journals Estimates of the relative abundance of long-finned pilot whales (Globicephala melas) in the Northeast Atlantic from 1987 to 2015 indicate no long-term trends

2019 ◽  
Vol 11 ◽  
Author(s):  
Daniel G. Pike ◽  
Thorvaldur Gunnlaugsson ◽  
Geneviève Desportes ◽  
Bjarni Mikkelsen ◽  
Gísli A. Vikingsson ◽  
...  
Keyword(s):  
Relative Abundance ◽  
North Atlantic ◽  
Distance Sampling ◽  
Field Methods ◽  
Pilot Whale ◽  
Globicephala Melas ◽  
The North ◽  
Spatial Coverage ◽  
Pilot Whales ◽  
Annual Distribution

North Atlantic Sightings Surveys (NASS) and associated surveys, covering a large but variable portion of the North Atlantic, were conducted in 1987, 1989, 1995, 2001, 2007 and 2015. Previous estimates of long-finned pilot whale (Globicephala melas) abundance, derived using conventional distance sampling (CDS), are not directly comparable to one another because of differing survey coverage, field methods and, in the case of the 1989 NASS, different survey timing. CDS was used to develop indices of relative abundance to determine if pilot whale abundance has changed over the 28-year period from 1987 to 2015. The varying spatial coverage of the surveys is accommodated by delineating common regions that were covered by: i) all 6 surveys, and ii) the 3 largest surveys (1989, 1995, and 2007). These “Index Regions” were divided into East and West subregions, and post-stratification was used to obtain abundance estimates for these index areas only. Estimates are provided using the sightings from the combined platforms for surveys that used double platforms or the primary platform only.Total abundance in the Index Regions, uncorrected for perception or availability biases, ranged from 54,264 (CV=0.48) in 2001 to 253,109 (CV=0.43) in 2015. There was no significant trend in the numbers of individuals or groups in either the 6 or 3 Survey Index Regions, and no consistent trend over the period. Power analyses indicate that negative annual growth rates of -3% to -5% would have been detectible over the entire period. The Index Regions comprise only a portion of the summer range of the species and changes in annual distribution clearly affect the results. Operational changes to the surveys, particularly in defining pilot whale groups, may also have introduced biases. Recommendations for future monitoring of the long-finned pilot whale population are provided.

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