Swimming velocities, breathing patterns, and estimated costs of locomotion in migrating gray whales, Eschrichtius robustus

1983 ◽  
Vol 61 (3) ◽  
pp. 647-652 ◽  
Author(s):  
James L. Sumich
Keyword(s):  
Minimum Cost ◽  
San Diego County ◽  
Swimming Velocity ◽  
Eschrichtius Robustus ◽  
Breathing Patterns ◽  
Method Of Least Squares ◽  
Cost Of Transport ◽  
Total Drag ◽  
Gray Whales ◽  
Energy Expenditures

This study was conducted to determine the swimming velocities and breathing patterns of south-migrating gray whales (Eschrichtius robustus) and to estimate their minimum costs of transport during migration. Swimming velocities and breathing patterns were monitored with theodolite techniques from a coastal vantage point on Point Loma, San Diego County, CA. Estimates of energy expenditures were based on observed breathing rates and on extrapolations of tidal lung volume and oxygen uptake measurements made on unrestrained and on captive gray whales. The results of 74 whales monitored over 354 whale∙km yielded mean velocities of 2.0 m∙s−1 and mean breathing rates of 0.72 breaths∙min−1. The regression of breathing rates on swimming velocities (V) by the method of least squares is best described by the equation, breathing rate = 0.5 + 0.024 V3.0. The calculated minimum cost of transport for a 12-m, 15-t whale was 0.046 W∙s∙N−1∙m−1 at the observed mean swimming velocity of 2 m∙s−1 during the southward migration. The coefficient of total drag was estimated to be 0.06. Rates of lipid depletion approximate 6% of body weight per month if no supplementary food intake occurs for the 4- to 6-month period each year that gray whales are presumed to fast.

Comparative swimming effort of migrating gray whales (Eschrichtius robustus) and calf cost of transport along Costa Azul, Baja California, Mexico

2008 ◽  
Vol 86 (4) ◽  
pp. 307-313 ◽  
Author(s):  
S. Rodríguez de la Gala-Hernández ◽  
G. Heckel ◽  
J. L. Sumich
Keyword(s):  
Baja California ◽  
Swimming Velocity ◽  
Eschrichtius Robustus ◽  
Cost Of Transport ◽  
Gray Whales

Swimming velocities and breathing rates were measured for migrating gray whales ( Eschrichtius robustus (Lilljeborg, 1861)) at Costa Azul, Baja California, to compare swimming effort of southbound whales, northbound whales without calves, and northbound mothers and calves. From December 2004 to May 2005, whales were followed using a theodolite to determine swimming velocity. Binoculars were used to count whale blows and their timings were recorded to determine breathing rates. Individual whale breathing rates (BR) were divided by their swimming velocity (V) to derive a comparative index of swimming effort in units of breaths per kilometre. There were significant differences in mean BR, V, and swimming effort among the three migrating groups (p < 0.05). Southbound migrating whales averaged a swimming effort of 7.4 breaths·km–1 (V = 1.9 m·s–1, BR = 0.8 breaths·min–1). Northbound whales without calves showed the lowest swimming effort of the three migrating groups (4.7 breaths·km–1, V = 1.8 m·s–1, BR = 0.5 breaths·min–1). Northbound mothers and calves had the same swimming velocity (V = 1.2 m·s–1), but BR and swimming effort were calculated separately yielding a swimming effort of 7.6 breaths·km–1 (BR = 0.5 breaths·min–1) for mothers and 10.1 breaths·km–1 (BR = 0.7 breaths·min–1) for calves. Cost of transport was calculated for northbound calves, yielding a range based on 1.5% and 3% tidal volumes of 0.25–0.34 and 0.51–0.58 J·kg–1·m–1, respectively.

Functional classification of harbor seal (Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success

1999 ◽  
Vol 77 (1) ◽  
pp. 74-87 ◽  
Author(s):  
Véronique Lesage ◽  
Mike O Hammill ◽  
Kit M Kovacs
Keyword(s):  
Minimum Cost ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Swimming Velocity ◽  
Harbor Seals ◽  
Cost Of Transport ◽  
Lawrence Estuary ◽  
Stomach Temperature ◽  
St Lawrence Estuary

Time-depth-speed recorders and stomach-temperature sensors were deployed on 11 harbor seals (Phoca vitulina) in the St. Lawrence estuary to examine their diving and foraging behavior. Fifty-four percent of dives were to depths of <4 m. Dives that were [Formula: see text] 4 m deep were classified into five distinct types, using a combination of principal components analysis and hierarchical and nonhierarchical clustering analyses. Feeding, indicated by a sharp decline in stomach temperature, occurred during dives of all five types, four of which were U-shaped, while one was V-shaped. Seals swam at speeds near the minimum cost of transport (MCT) during descents and ascents. V-shaped dives had mean depths of 5.8 m, lasted an average of 40 s, and often preceded or followed periods of shallow-water (<4 m) activity. Seals invariably dove to the bottom when performing U-shaped dives. These dives were to an average depth of 20 m during daylight and occurred in shallower waters (~8 m) at twilight and during the night. Once on the bottom, seals (i) swam at MCT speeds with occasional bursts of speed, (ii) swam at speeds near MCT but not exceeding it, or (iii) remained stationary or swam slowly at about 0.15 m/s, occasionally swimming faster. It is unlikely that all dives to depths [Formula: see text] 4 m are dedicated to foraging. However, the temporal segregation of dive types suggests that all types are used during foraging, although they may represent different strategies.

scholarly journals Energetics of locomotion by the Australian water rat (Hydromys chrysogaster): a comparison of swimming and running in a semi-aquatic mammal

1999 ◽  
Vol 202 (4) ◽  
pp. 353-363 ◽  
Author(s):  
F.E. Fish ◽  
R.V. Baudinette
Keyword(s):  
Metabolic Rate ◽  
Bound Water ◽  
Minimum Cost ◽  
Wave Drag ◽  
Swimming Velocity ◽  
Cost Of Transport ◽  
Australian Water ◽  
Aquatic Mammal ◽  
Hydromys Chrysogaster ◽  
Aquatic Mammals

Semi-aquatic mammals occupy a precarious evolutionary position, having to function in both aquatic and terrestrial environments without specializing in locomotor performance in either environment. To examine possible energetic constraints on semi-aquatic mammals, we compared rates of oxygen consumption for the Australian water rat (Hydromys chrysogaster) using different locomotor behaviors: swimming and running. Aquatic locomotion was investigated as animals swam in a water flume at several speeds, whereas water rats were run on a treadmill to measure metabolic effort during terrestrial locomotion. Water rats swam at the surface using alternate pelvic paddling and locomoted on the treadmill using gaits that included walk, trot and half-bound. Water rats were able to run at twice their maximum swimming velocity. Swimming metabolic rate increased with velocity in a pattern similar to the ‘humps’ and ‘hollows’ for wave drag experienced by bodies moving at the water surface. Metabolic rate increased linearly during running. Over equivalent velocities, the metabolic rate for running was 13–40 % greater than for swimming. The minimum cost of transport for swimming (2.61 J N-1 m-1) was equivalent to values for other semi-aquatic mammals. The lowest cost for running (2.08 J N-1 m-1) was 20 % lower than for swimming. When compared with specialists at the extremes of the terrestrial-aquatic continuum, the energetic costs of locomoting either in water or on land were high for the semi-aquatic Hydromys chrysogaster. However, the relative costs for H. chrysogaster were lower than when an aquatic specialist attempts to move on land or a terrestrial specialist attempts to swim.

Hydrodynamic drag in steller sea lions (Eumetopias jubatus)

2000 ◽  
Vol 203 (12) ◽  
pp. 1915-1923 ◽  
Author(s):  
L.L. Stelle ◽  
R.W. Blake ◽  
A.W. Trites
Keyword(s):  
Minimum Cost ◽  
The Body ◽  
Hydrodynamic Drag ◽  
Eumetopias Jubatus ◽  
Steller Sea Lions ◽  
California Sea Lions ◽  
Cost Of Transport ◽  
Sea Lions ◽  
Drag Forces ◽  
The Individual

Drag forces acting on Steller sea lions (Eumetopias jubatus) were investigated from ‘deceleration during glide’ measurements. A total of 66 glides from six juvenile sea lions yielded a mean drag coefficient (referenced to total wetted surface area) of 0.0056 at a mean Reynolds number of 5.5×10(6). The drag values indicate that the boundary layer is largely turbulent for Steller sea lions swimming at these Reynolds numbers, which are past the point of expected transition from laminar to turbulent flow. The position of maximum thickness (at 34 % of the body length measured from the tip of the nose) was more anterior than for a ‘laminar’ profile, supporting the idea that there is little laminar flow. The Steller sea lions in our study were characterized by a mean fineness ratio of 5.55. Their streamlined shape helps to delay flow separation, reducing total drag. In addition, turbulent boundary layers are more stable than laminar ones. Thus, separation should occur further back on the animal. Steller sea lions are the largest of the otariids and swam faster than the smaller California sea lions (Zalophus californianus). The mean glide velocity of the individual Steller sea lions ranged from 2.9 to 3.4 m s(−)(1) or 1.2-1.5 body lengths s(−)(1). These length-specific speeds are close to the optimum swim velocity of 1.4 body lengths s(−)(1) based on the minimum cost of transport for California sea lions.

Efficiency of uphill locomotion in nocturnal and diurnal lizards

1996 ◽  
Vol 199 (3) ◽  
pp. 587-592 ◽  
Author(s):  
C Farley ◽  
M Emshwiller
Keyword(s):  
Body Mass ◽  
Low Cost ◽  
Minimum Cost ◽  
Mechanical Work ◽  
Energetic Cost ◽  
Cost Of Transport ◽  
Unit Distance ◽  
Cost Of Locomotion ◽  
Average Body Mass ◽  
Average Body

Nocturnal geckos can walk on level ground more economically than diurnal lizards. One hypothesis for why nocturnal geckos have a low cost of locomotion is that they can perform mechanical work during locomotion more efficiently than other lizards. To test this hypothesis, we compared the efficiency of the nocturnal gecko Coleonyx variegatus (average body mass 4.2 g) and the diurnal skink Eumeces skiltonianus (average body mass 4.8 g) when they performed vertical work during uphill locomotion. We measured the rate of oxygen consumption when each species walked on the level and up a 50 slope over a range of speeds. For Coleonyx variegatus, the energetic cost of traveling a unit distance (the minimum cost of transport, Cmin) increased from 1.5 to 2.7 ml O2 kg-1 m-1 between level and uphill locomotion. For Eumeces skiltonianus, Cmin increased from 2.5 to 4.7 ml O2 kg-1 m-1 between level and uphill locomotion. By taking the difference between Cmin for level and uphill locomotion, we found that the efficiency of performing vertical work during locomotion was 37 % for Coleonyx variegatus and 19 % for Eumeces skiltonianus. The similarity between the 1.9-fold difference in vertical efficiency and the 1.7-fold difference in the cost of transport on level ground is consistent with the hypothesis that nocturnal geckos have a lower cost of locomotion than other lizards because they can perform mechanical work during locomotion more efficiently.

Using two drones to simultaneously monitor visual and acoustic behaviour of gray whales (Eschrichtius robustus) in Baja California, Mexico

2020 ◽  
Vol 525 ◽  
pp. 151321 ◽  
Author(s):  
Héloïse Frouin-Mouy ◽  
Ludovic Tenorio-Hallé ◽  
Aaron Thode ◽  
Steven Swartz ◽  
Jorge Urbán
Keyword(s):  
Baja California ◽  
Eschrichtius Robustus ◽  
Gray Whales ◽  
Acoustic Behaviour

Responses of gray whales (Eschrichtius robustus) to nonbiological noise

1983 ◽  
Vol 74 (S1) ◽  
pp. S54-S55
Author(s):  
Marilyn E. Dahlheim ◽  
H. Dean Fisher
Keyword(s):  
Eschrichtius Robustus ◽  
Gray Whales
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