Energy Costs of Walking in Camels,<i>Camelus dromedarius</i>

Yousef, Mohamed; Webster, M. E. D.; Yousef, O. M.

doi:10.1086/physzool.62.5.30156197

Cited by 11 publications

(13 citation statements)

References 17 publications

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“…Ewievd m donkeys seems to be very much smaller than values reported for cattle (Brody, 1945;Agricultural Research Council (ARC), 1980;Lawrence and Stibbards, 1990), buffaloes (Lawrence and Stibbards, 1990) and horses (Brody, 1945;Hintz, Roberts, Sabin and Schryver, 1971), but comparable with values obtained for camels (Yousef, Webster and Yousef, 1989). The formulae proposed by Tucker (1969) and Taylor, Heglund and Maloiy (1982) for predicting the energy cost of E w both highly overestimate the actual value obtained in this study for donkeys.…”

Section: Dijkmancontrasting

confidence: 57%

“…Ecievei m donkeys was very much lower than the values reported for cattle (ARC, 1980;Lawrence and Stibbards, 1990), buffaloes and ponies (Lawrence and Stibbards, 1990), but, as with E w , similar to camels (Yousef et al, 1989). Taylor (1986), suggested that anatomic adaptation allows African women to support small loads using non-muscular structural elements.…”

Section: Dijkmanmentioning

confidence: 73%

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A note on the influence of negative gradients on the energy expenditure of donkeys walking, carrying and pulling loads

Dijkman¹

1992

Anim. Sci.

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The extra energy used for walking on the level and on negative gradients above that used when standing still (Ew) (J/m per kg live weight) was measured in two entire male donkeys (Equus asinus). E w was not affected by speed within the measured range (V = 0-6 to 1-3 m/s) but gradient (0, -10%, -15%) had a significant effect EWJOT; = 0-97 (s.e. 0-02), E n _ m = 0-55 (s.e. = 0-03) and E W _ 1S% = 0-67 (s.e. 0-03). The extra energy cost of carrying loads (E c ), defined as J/m per kg carried was measured using the same animals. Loads were placed over the animals shoulders and speed was varied within the range 0-6 to 1-3 m/s (E ckvel = 1-1 (s.e. 0-04), E c _ w% = 2-7 (s.e. 0-17) and E c _ 15% = 3-3 (s.e. 0-20) were significantly different. The energy cost of pulling loads (E p ) (f/m per kg) was measured while the animals pulled loads up to proportionately 0-17 of their live weight. The animals wore a breast-plate harness and walking speed was varied within the range 0-6 to 1-3 m/s. Mean values were 26-5 (s.e. 0-72) on the level, 15-3 (s.e. 1-2) on the -10% gradient and 6-2 (s.e. 0-43) on the -15% gradient.The two donkeys used in this experiment were more efficient in both carrying and pulling loads than oxen and buffaloes. Negative gradients have a significant effect on energy consumption and when estimating the energy expenditure of working animals this factor should be taken into account.

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Section: Dijkmancontrasting

confidence: 57%

Section: Dijkmanmentioning

confidence: 73%

A note on the influence of negative gradients on the energy expenditure of donkeys walking, carrying and pulling loads

Dijkman¹

1992

Anim. Sci.

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“…As a result of variations in whole-animal COT tot between adult and sub-adult elephants, migration might result in differential intraspecific energetic challenges, a topic worthy of further investigation. , as is characteristic of the interspecific relationship (Eqn 1) reported by Taylor et al (Taylor et al, 1982), but is a function of ϷM b 0 , characteristic of the intraspecific relationship reported in horses and camels (Yousef et al, 1989;Griffin et al, 2004;Maloiy et al, 2009). …”

Section: Physiological Similarity Between Adult Asian and Sub-adult Amentioning

confidence: 87%

“…Because of geometric and physiological similarity, body mass does not have the same effect on COT min at the intraspecific level, or between closely related species, as it does at the interspecific level. In geometrically similar (Griffin et al, 2004) and camels from 240 to 580kg (Yousef et al, 1989;Maloiy et al, 2009) compared with the interspecific relationship M b -0.316 (Eqn 1). African and Asian elephants, along with extinct mammoths (Mammuthus), comprise the family Elephantidae and share common ancestry (Haynes, 1991;Krause et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Minimum cost of transport in Asian elephants: do we really need a bigger elephant?

Langman

Rowe

Roberts

et al. 2012

Journal of Experimental Biology

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SUMMARYBody mass is the primary determinant of an animalʼs energy requirements. At their optimum walking speed, large animals have lower mass-specific energy requirements for locomotion than small ones. In animals ranging in size from 0.8g (roach) to 260kg (zebu steer), the minimum cost of transport (COT min ) decreases with increasing body size roughly as COT min ϰbody mass (M b ) -0.316±0.023 (95% CI). Typically, the variation of COT min with body mass is weaker at the intraspecific level as a result of physiological and geometric similarity within closely related species. The interspecific relationship estimates that an adult elephant, with twice the body mass of a mid-sized elephant, should be able to move its body approximately 23% cheaper than the smaller elephant. We sought to determine whether adult Asian and sub-adult African elephants follow a single quasi-intraspecific relationship, and extend the interspecific relationship between COT min and body mass to 12-fold larger animals. Physiological and possibly geometric similarity between adult Asian elephants and sub-adult African elephants caused body mass to have a no effect on COT min (COT min ϰM b 0.007±0.455). The COT min in elephants occurred at walking speeds between 1.3 and ~1.5ms . The quasi-intraspecific relationship between body mass and COT min among elephants caused the interspecific relationship to underestimate COT min in larger elephants.

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“…According to our walking allometric analysis, the net energy cost of walking should be lower than that of running for large animals, but the converse for small animals (Fig.·5), and at a mass of ~20·kg, where the walking and running regression lines intersect, an animal's E walk and E run should in theory be equivalent. In support of this view, large animal species have an E walk considerably lower than their E run , as found in humans (Margaria, 1976), Shetland ponies (Hoyt and Taylor, 1981) (D. F. Hoyt, personal communication), Arabian, Draft and Miniature horses (Griffin et al, 2004) (T. M. Griffin, personal communication), Standardbred horses (Minetti et al, 1999), ostriches (Rubenson et al, 2004) and camels (Yousef et al, 1989;Evans et al, 1994) (see Tables·3 and 4) despite the gross energy cost of walking and running in several of these species being the same (Hoyt and Taylor, 1981;Griffin et al, 2004). By contrast, E walk is higher compared to E run in all but two of the 13 small mammal and bird species (0.021-22·kg) studied by Taylor et al (Taylor et al, 1970) and Fedak et al (Fedak et al, 1974).…”

Section: Comparative Cost Of Human Walkingmentioning

confidence: 90%

Reappraisal of the comparative cost of human locomotion using gait-specific allometric analyses

Rubenson

Heliams²,

Maloney

et al. 2007

Journal of Experimental Biology

106

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SUMMARY The alleged high net energy cost of running and low net energy cost of walking in humans have played an important role in the interpretation of the evolution of human bipedalism and the biomechanical determinants of the metabolic cost of locomotion. This study re-explores how the net metabolic energy cost of running and walking (J kg–1m–1) in humans compares to that of animals of similar mass using new allometric analyses of previously published data. Firstly, this study shows that the use of the slope of the regression between the rate of energy expenditure and speed to calculate the net energy cost of locomotion overestimates the net cost of human running. Also, the net energy cost of human running is only 17% higher than that predicted based on their mass. This value is not exceptional given that over a quarter of the previously examined mammals and birds have a net energy cost of running that is 17% or more above their allometrically predicted value. Using a new allometric equation for the net energy cost of walking, this study also shows that human walking is 20%less expensive than predicted for their mass. Of the animals used to generate this equation, 25% have a relatively lower net cost of walking compared with their allometrically predicted value. This new walking allometric analysis also indicates that the scaling of the net energy cost of locomotion with body mass is gait dependent. In conclusion, the net costs of running and walking in humans are moderately different from those predicted from allometry and are not remarkable for an animal of its size.

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Energy Costs of Walking in Camels,Camelus dromedarius

Cited by 11 publications

References 17 publications

A note on the influence of negative gradients on the energy expenditure of donkeys walking, carrying and pulling loads

A note on the influence of negative gradients on the energy expenditure of donkeys walking, carrying and pulling loads

Minimum cost of transport in Asian elephants: do we really need a bigger elephant?

Reappraisal of the comparative cost of human locomotion using gait-specific allometric analyses

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