Swimming gaits, passive drag and buoyancy of diving sperm whales Physeter macrocephalus.
01 May 2004-The Journal of Experimental Biology (Company of Biologists)-Vol. 207, Iss: 11, pp 1953-1967
TL;DR: Whales glides more during portions of dives when buoyancy aided their movement, and whales that glided more during ascent glided less during descent (and vice versa), supporting the hypothesis that buoyancy influences behavioural swimming decisions.
Abstract: SUMMARY Drag and buoyancy are two primary external forces acting on diving marine
mammals. The strength of these forces modulates the energetic cost of movement
and may influence swimming style (gait). Here we use a high-resolution digital
tag to record depth, 3-D orientation, and sounds heard and produced by 23
deep-diving sperm whales in the Ligurian Sea and Gulf of Mexico. Periods of
active thrusting versus gliding were identified through analysis of
oscillations measured by a 3-axis accelerometer. Accelerations during 382
ascent glides of five whales (which made two or more steep ascents and for
which we obtained a measurement of length) were strongly affected by depth and
speed at Reynold9s numbers of 1.4–2.8×107. The
accelerations fit a model of drag, air buoyancy and tissue buoyancy forces
with an r2 of 99.1–99.8% for each whale. The model
provided estimates (mean ± s.d.) of the drag coefficient
(0.00306±0.00015), air carried from the surface (26.4±3.9 l
kg-3 mass), and tissue density (1030±0.8 kg m-3)
of these five animals. The model predicts strong positive buoyancy forces in
the top 100 m of the water column, decreasing to near neutral buoyancy at
250–850 m. Mean descent speeds (1.45±0.19 m s-1) were
slower than ascent speeds (1.63±0.22 m s-1), even though
sperm whales stroked steadily (glides 5.3±6.3%) throughout descents and
employed predominantly stroke-and-glide swimming (glides 37.7±16.4%)
during ascents. Whales glided more during portions of dives when buoyancy
aided their movement, and whales that glided more during ascent glided less
during descent (and vice versa), supporting the hypothesis that
buoyancy influences behavioural swimming decisions. One whale rested at∼
10 m depth for more than 10 min without fluking, regulating its buoyancy
by releasing air bubbles.
Citations
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TL;DR: Using current models of breath-hold diving, it is inferred that beaked whales' natural diving behaviour is inconsistent with known problems of acute nitrogen supersaturation and embolism, and possible decompression problems are more likely to result from an abnormal behavioural response to sonar.
Abstract: Sound-and-orientation recording tags (DTAGs) were used to study 10 beaked whales of two poorly known species, Ziphius cavirostris (Zc) and Mesoplodon densirostris (Md). Acoustic behaviour in the deep foraging dives performed by both species (Zc: 28 dives by seven individuals; Md: 16 dives by three individuals) shows that they hunt by echolocation in deep water between 222 and 1885 m, attempting to capture about 30 prey/dive. This food source is so deep that the average foraging dives were deeper (Zc: 1070 m; Md: 835 m) and longer (Zc: 58 min; Md: 47 min) than reported for any other air-breathing species. A series of shallower dives, containing no indications of foraging, followed most deep foraging dives. The average interval between deep foraging dives was 63 min for Zc and 92 min for Md. This long an interval may be required for beaked whales to recover from an oxygen debt accrued in the deep foraging dives, which last about twice the estimated aerobic dive limit. Recent reports of gas emboli in beaked whales stranded during naval sonar exercises have led to the hypothesis that their deep-diving may make them especially vulnerable to decompression. Using current models of breath-hold diving, we infer that their natural diving behaviour is inconsistent with known problems of acute nitrogen supersaturation and embolism. If the assumptions of these models are correct for beaked whales, then possible decompression problems are more likely to result from an abnormal behavioural response to sonar.
432 citations
Cites background from "Swimming gaits, passive drag and bu..."
...…is that a whale, already at or near its ADL by the end of the foraging phase of a deep dive, might seek to minimize the cost of transport by performing a long duration, but metabolically cheap, gliding ascent as described for Weddell seals (Sato et al., 2003) and sperm whales (Miller et al., 2004)....
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TL;DR: Similarity in foraging behaviour in the three regions and high diving efficiencies suggest that the success of sperm whales as mesopelagic predators is due in part to long-range echolocation of deep prey patches, efficient locomotion and a large aerobic capacity during diving.
Abstract: 1. Digital tags were used to describe diving and vocal behaviour of sperm whales during 198 complete and partial foraging dives made by 37 individual sperm whales in the Atlantic Ocean, the Gulf of Mexico and the Ligurian Sea. 2. The maximum depth of dive averaged by individual differed across the three regions and was 985 m (SD = 124.3), 644 m (123.4) and 827 m (60.3), respectively. An average dive cycle consisted of a 45 min (6.3) dive with a 9 min (3.0) surface interval, with no significant differences among regions. On average, whales spent greater than 72% of their time in foraging dive cycles. 3. Whales produced regular clicks for 81% (4.1) of a dive and 64% (14.6) of the descent phase. The occurrence of buzz vocalizations (also called 'creaks') as an indicator of the foraging phase of a dive showed no difference in mean prey capture attempts per dive between regions [18 buzzes/dive (7.6)]. Sperm whales descended a mean of 392 m (144) from the start of regular clicking to the first buzz, which supports the hypothesis that regular clicks function as a long-range biosonar. 4. There were no significant differences in the duration of the foraging phase [28 min (6.0)] or percentage of the dive duration in the foraging phase [62% (7.3)] between the three regions, with an overall average proportion of time spent actively encountering prey during dive cycles of 0.53 (0.05). Whales maintained their time in the foraging phase by decreasing transit time for deeper foraging dives. 5. Similarity in foraging behaviour in the three regions and high diving efficiencies suggest that the success of sperm whales as mesopelagic predators is due in part to long-range echolocation of deep prey patches, efficient locomotion and a large aerobic capacity during diving.
364 citations
Cites background from "Swimming gaits, passive drag and bu..."
...Increased foraging phase durations correlate with increased buzz rates in these whales (Miller et al. 2004a), as has been seen elsewhere in foraging dives of male sperm whales (Jaquet et al. 2001)....
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...Sperm whales have a streamlined body form with a low drag coefficient at typical travel speeds (Miller et al. 2004b)....
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...In addition to body shape/anatomical adaptations, sperm whales make extensive use of gliding during transit using buoyancy forces to power more efficient dives (Williams et al. 2000; Miller et al. 2004b)....
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TL;DR: This energetic foraging tactic focused on a single or few prey items has not been observed previously in deep-diving mammals but resembles the high-risk/high-gain strategy of some terrestrial hunters such as cheetahs.
Abstract: Summary 1 Empirical testing of optimal foraging models for breath-hold divers has been difficult Here we report data from sound and movement recording DTags placed on 23 short-finned pilot whales off Tenerife to study the foraging strategies used to catch deep-water prey 2 Day and night foraging dives had a maximum depth and duration of 1018 m and 21 min Vocal behaviour during dives was consistent with biosonar-based foraging, with long series of echolocation clicks interspersed with buzzes Similar buzzes have been associated with prey capture attempts in other echolocating species 3 Foraging dives seemed to adapt to circadian rhythms Deep dives during the day were deeper, but contained fewer buzzes (median 1), than night-time deep dives (median 5 buzzes) 4 In most deep (540‐1019 m) daytime dives with buzzes, a downward directed sprint reaching up to 9 m s ‐1 occurred just prior to a buzz and coincided with the deepest point in the dive, suggestive of a chase after escaping prey 5 A large percentage (10‐36%) of the drag-related locomotion cost of these dives (15 min long) is spent in sprinting (19‐79 s) This energetic foraging tactic focused on a single or few prey items has not been observed previously in deep-diving mammals but resembles the high-risk/high-gain strategy of some terrestrial hunters such as cheetahs 6 Deep sprints contrast with the expectation that deep-diving mammals will swim at moderate speeds optimized to reduce oxygen consumption and maximize foraging time at depth Pilot whales may have developed this tactic to target a deep-water niche formed by large/calorific/fast moving prey such as giant squid
262 citations
Cites background from "Swimming gaits, passive drag and bu..."
...Studies on biosonar foraging by free-ranging sperm and beaked whales (Johnson et al. 2004; Miller et al. 2004b; Madsen et al. 2005) have shown that these species use long series of clicks to echolocate prey during deep dives, while capture attempts are marked by short series of clicks emitted at…...
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...…data show a highly stereotyped behaviour with buzzes, similar to those associated with prey capture attempts in other echolocating species (Griffin 1958; Miller et al. 2004b; Madsen et al. 2005), happening on average very close in depth to, and only a few seconds after, the sprints....
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TL;DR: The hypothesis that creaks are an echolocation signal adapted for foraging, analogous to terminal buzzes in taxonomically diverse echlocating species, strongly support the hypothesis thatcreaks are produced during prey capture.
Abstract: During foraging dives, sperm whales (Physeter macrocephalus) produce long series of regular clicks at 0.5-2 s intervals interspersed with rapid-click buzzes called "creaks". Sound, depth and orientation recording Dtags were attached to 23 whales in the Ligurian Sea and Gulf of Mexico to test whether the behaviour of diving sperm whales supports the hypothesis that creaks are produced during prey capture. Sperm whales spent most of their bottom time within one or two depth bands, apparently feeding in vertically stratified prey layers. Creak rates were highest during the bottom phase: 99.8% of creaks were produced in the deepest 50% of dives, 57% in the deepest 15% of dives. Whales swam actively during the bottom phase, producing a mean of 12.5 depth inflections per dive. A mean of 32% of creaks produced during the bottom phase occurred within 10 s of an inflection (13x more than chance). Sperm whales actively altered their body orientation throughout the bottom phase with significantly increased rates of change during creaks, reflecting increased manoeuvring. Sperm whales increased their bottom foraging time when creak rates were higher. These results all strongly support the hypothesis that creaks are an echolocation signal adapted for foraging, analogous to terminal buzzes in taxonomically diverse echolocating species.
262 citations
TL;DR: Examination of body kinematics at depth reveals variable lunge-feeding behavior in the context of distinct kinematic modes, which exhibit temporal coordination of rotational torques with translational accelerations.
Abstract: Fin whales are among the largest predators on earth, yet little is known about their foraging behavior at depth. These whales obtain their prey by lunge-feeding, an extraordinary biomechanical event where large amounts of water and prey are engulfed and filtered. This process entails a high energetic cost that effectively decreases dive duration and increases post-dive recovery time. To examine the body mechanics of fin whales during foraging dives we attached high-resolution digital tags, equipped with a hydrophone, a depth gauge and a dual-axis accelerometer, to the backs of surfacing fin whales in the Southern California Bight. Body pitch and roll were estimated by changes in static gravitational acceleration detected by orthogonal axes of the accelerometer, while higher frequency, smaller amplitude oscillations in the accelerometer signals were interpreted as bouts of active fluking. Instantaneous velocity of the whale was determined from the magnitude of turbulent flow noise measured by the hydrophone and confirmed by kinematic analysis. Fin whales employed gliding gaits during descent, executed a series of lunges at depth and ascended to the surface by steady fluking. Our examination of body kinematics at depth reveals variable lunge-feeding behavior in the context of distinct kinematic modes, which exhibit temporal coordination of rotational torques with translational accelerations. Maximum swimming speeds during lunges match previous estimates of the flow-induced pressure needed to completely expand the buccal cavity during feeding.
255 citations
Cites background or methods from "Swimming gaits, passive drag and bu..."
...…dolphins (Skrovan et al., 1999) and blue whales (Williams et al., 2000) glide during descent and actively stroke to the surface, whereas more positively buoyant right whales (Nowacek et al., 2001) and sperm whales (Miller et al., 2004) actively stroke to depth and glide more during ascent....
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...Similarly, sperm whales reached maximum speeds near the end of each descent, but such speeds were accompanied by fluking (Miller et al., 2004)....
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...As a corollary, whale speed derived from the kinematics of the body, VK, was estimated by dividing the vertical velocity obtained from the depth profile by the sine of the body pitch angle (see Miller et al., 2004)....
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References
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Book•
01 Jan 1993TL;DR: The fifth edition of this hugely successful textbook retains the quality of earlier editions while at the same time seeing numerous minor improvements and major additions as mentioned in this paper, including a new chapter on singular values and singular vectors, including ways to analyze a matrix of data.
Abstract: Linear algebra is something all mathematics undergraduates and many other students, in subjects ranging from engineering to economics, have to learn. The fifth edition of this hugely successful textbook retains the quality of earlier editions while at the same time seeing numerous minor improvements and major additions. The latter include: a new chapter on singular values and singular vectors, including ways to analyze a matrix of data; a revised chapter on computing in linear algebra, with professional-level algorithms and code that can be downloaded for a variety of languages; a new section on linear algebra and cryptography; and a new chapter on linear algebra in probability and statistics. A dedicated and active website also offers solutions to exercises as well as new exercises from many different sources (e.g. practice problems, exams, development of textbook examples), plus codes in MATLAB, Julia, and Python.
1,913 citations
DOI•
01 Jan 1983
TL;DR: In this article, the APSO Joint Panel on Oceanographic Tables and Standards (APSO) and SCOR Working Group (SCOR) have published a joint report on oceanographic tables and standards.
Abstract: Endorsed by
Unesco/SCOR/ICES/lAPSO Joint Panel
on Oceanographic Tables and Standards
and SCOR Working Group 51
1,534 citations
"Swimming gaits, passive drag and bu..." refers background in this paper
...Seawater density ρw is the only depth influence on term 1 and can be calculated for any depth using CTD profiles near tag locations to obtain salinity and temperature (Fofonoff and Millard, 1983; Morgan, 1994)....
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Book•
01 Jan 1981
TL;DR: His discussion of the relationship between fluid flow and biological design now includes sections on jet propulsion, biological pumps, swimming, blood flow, and surface waves, and on acceleration reaction and Murray's law.
Abstract: Both a landmark text and reference book, Steven Vogel's "Life in Moving Fluids" has also played a catalytic role in research involving the applications of fluid mechanics to biology. In this revised edition, Vogel continues to combine humor and clear explanations as he addresses biologists and general readers interested in biological fluid mechanics, offering updates on the field over the last dozen years and expanding the coverage of the biological literature. His discussion of the relationship between fluid flow and biological design now includes sections on jet propulsion, biological pumps, swimming, blood flow, and surface waves, and on acceleration reaction and Murray's law. This edition contains an extensive bibliography for readers interested in designing their own experiments.
1,431 citations
"Swimming gaits, passive drag and bu..." refers background or methods in this paper
...each other fairly closely based upon the flow regime at the appropriate Reynold’s number (Vogel, 1981)....
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...Thus, the marine mammal species for which drag has been estimated or measured match each other fairly closely based upon the flow regime at the appropriate Reynold’s number (Vogel, 1981)....
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...For each sub-glide we obtained a Reynold’s number (Re) using the animal’s length estimate and the mean speed during the sub-glide (Vogel, 1981)....
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..., 1998), and natural selection should favor adaptations that reduce these costs (Vogel, 1981)....
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...At the high Reynold’s number experienced by these large animals, flow is likely to be entirely turbulent (Vogel, 1981)....
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Journal Article•
TL;DR: The treatment of benign ulcer disease with X-irradiation is certainly controversial and has not been widely accepted for general use in most medical centers.
Abstract: in dogs lasting up to 40 days following moderate doses of 1600 rads in eight treatments of X-irradiation. There is a discussion of the difficulties encountered in attempting to irradiate gastric mucosa with radioactive sources placed directly within the stomach. The techniques of external beam treatment used at the University of Chicago are described in detail. Finally, the clinical results and complications are presented for this rather considerable experience, over 3000 patients treated during a 35-yr period. The treatment of benign ulcer disease with X-irradiation is certainly controversial and has not been widely accepted for general use in most medical centers. The results of this considerable clinical experience are difficult to assess because of the variability in the natural history of this condition. Most encouraging are the results of a randomized prospective study carried out by Erwin Levin with 68 patients, all of whom were treated with intensive medical management, half of whom were randomly selected to receive approximately 2000 rads to the fundus and body of the stomach in about ten total treatments. The control group had significantly more failures in therapy than the irradiated group. In a 5-yr period over 70% of the nonir-radiated patients had recurrent ulcers compared to only 11 % in the irradiated group. The irradiated patients showed decreased levels of basal and Histalog stimulated free acid excretion. Particular emphasis is placed on the examination of the possibility of radiation induced neoplasia. Careful followup of the patients treated at the University of Chicago gives no indication that this is a significant complication. A number of criticisms may be offered. The general format of the book, a number of small independently written chapters, leads to disorganization, fragmentation, and needless repetition. In many instances the details of the radiation technique and the suggested mechanisms of action are not up to the standards of modern radiation therapy and radiobiology. This will be more annoying to radiation therapists than other readers. When describing what is clearly a nonuniversally accepted treatment, it might have been useful to include a brief presentation by a gastroenterologist not enthusiastic about this technique. In a very brief chapter, five pages, Dr. Melvin Griem, one of the country's leading radiation therapists and Director of the Tumor Institute at the University of Chicago, describes the techniques and dosimetry used at that institution in great detail, but conspicuously fails to discuss the usefulness of the treatment and …
803 citations
"Swimming gaits, passive drag and bu..." refers background in this paper
...In large marine mammals, the primary forces are hydrodynamic drag, lift and buoyancy (Schmidt-Nielsen, 1997)....
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...Such temperature gradients may reduce external body temperatures during long dives in cold, deep water, particularly if blood flow to extremities is restricted (Schmidt-Nielsen, 1997)....
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TL;DR: In this paper, a novel archival tag, called the DTAG, has been developed to monitor the behavior of marine mammals, and their response to sound, continuously throughout the dive cycle.
Abstract: Definitive studies on the response of marine mammals to anthropogenic sound are hampered by the short surface time and deep-diving lifestyle of many species. A novel archival tag, called the DTAG, has been developed to monitor the behavior of marine mammals, and their response to sound, continuously throughout the dive cycle. The tag contains a large array of solid-state memory and records continuously from a built-in hydrophone and suite of sensors. The sensors sample the orientation of the animal in three dimensions with sufficient speed and resolution to capture individual fluke strokes. Audio and sensor recording is synchronous so the relative timing of sounds and motion can be determined precisely. The DTAG has been attached to more than 30 northern right whales (Eubalaena glacialis) and 20 sperm whales (Physeter macrocephalus) with recording duration of up to 12 h per deployment. Several deployments have included sound playbacks to the tagged whale and a transient response to at least one playback is evident in the tag data.
771 citations
"Swimming gaits, passive drag and bu..." refers background in this paper
...If gases were released from tissues such as the rete mirabilein large quantities during ascent, we would expend to find negative residuals for the shallowest glides where gas should be released most quickly from solution (Kooyman, 1973)....
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...A larger lung volume is predicted from a general mammalian body size regression line that includes smaller mammals (Kooyman, 1973), but there are few data and significant variability for the larger whales....
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...While there may be gas exchange as long as the alveoli contain air, the lungs of cetaceans appear to have adaptations for rapid alveolar collapse upon diving (Kooyman, 1973)....
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