The Physiology and Energetics of Bat Flight

1972 ◽  
Vol 57 (2) ◽  
pp. 317-335 ◽  
Author(s):  
STEVEN P. THOMAS ◽  
RODERICK A. SUTHERS
Keyword(s):  
Metabolic Rate ◽  
Metabolic Cost ◽  
Minute Volume ◽  
High Metabolic Rate ◽  
Abrupt Increase ◽  
Bird Flight ◽  
Terrestrial Mammals ◽  
Oxygen Capacity ◽  
Physiological Adaptations ◽  
Phyllostomus Hastatus

1. The energetics and physiological responses to flight of the echolocating bat Phyllostomus hastatus were studied to determine the energy requirements and physiological adaptations for mammalian flight. 2. The metabolic cost of bat flight is approximately comparable to that of bird flight and requires a metabolic rate appreciably greater than has been reported for terrestrial mammals during exercise. During flight P. hastatus consumed between 24.7 and 29.1 ml O2 (g h)-1, which is about four times its metabolic rate immediately prior to flight and more than 30 times its oxygen consumption while resting with a TR of 36.5 °C in a small chamber. 3. The onset of flight is accompanied by an abrupt increase in both the heart rate, from about 8.7 to 13 beats/sec, and the respiratory rate, from 3 to about 9.6/sec. Rectal temperature is elevated during flight and maintained at about 41.8 °C. The respiratory quotient, which averages 0.83 in a quietly resting bat, rises to a little over 1.0 during the first few minutes of flight. 4. The minimum estimated tidal volume during flight is about 1.4 ml. One respiratory cycle occurs with each wingbeat, corresponding to an estimated minute volume of 840 ml, which is comparable to that reported for the flying budgerigar. The amount of oxygen extracted by P. hastatus from a given volume of tidal air is also comparable to the efficiency of ventilation reported for this bird. 5. High hematocrit values of about 60%, and a high oxygen capacity of 27.5 vol % of P. hastatus blood, must represent important adaptations for enabling the flying bat to maintain such a high metabolic rate.

scholarly journals Energetics of terrestrial locomotion of the platypus Ornithorhynchus anatinus

2001 ◽  
Vol 204 (4) ◽  
pp. 797-803 ◽  
Author(s):  
F.E. Fish ◽  
P.B. Frappell ◽  
R.V. Baudinette ◽  
P.M. MacFarlane
Keyword(s):  
Metabolic Rate ◽  
Metabolic Cost ◽  
Standard Metabolic Rate ◽  
Cost Of Transport ◽  
Terrestrial Locomotion ◽  
Terrestrial Mammals ◽  
Video Recordings ◽  
Ornithorhynchus Anatinus ◽  
The Cost ◽  
Limb Structure

The platypus Ornithorhynchus anatinus Shaw displays specializations in its limb structure for swimming that could negatively affect its terrestrial locomotion. Platypuses walked on a treadmill at speeds of 0.19-1.08 m × s(−1). Video recordings were used for gait analysis, and the metabolic rate of terrestrial locomotion was studied by measuring oxygen consumption. Platypuses used walking gaits (duty factor >0.50) with a sprawled stance. To limit any potential interference from the extensive webbing on the forefeet, platypuses walk on their knuckles. Metabolic rate increased linearly over a 2.4-fold range with increasing walking speed in a manner similar to that of terrestrial mammals, but was low as a result of the relatively low standard metabolic rate of this monotreme. The dimensionless cost of transport decreased with increasing speed to a minimum of 0.79. Compared with the cost of transport for swimming, the metabolic cost for terrestrial locomotion was 2.1 times greater. This difference suggests that the platypus may pay a price in terrestrial locomotion by being more aquatically adapted than other semi-aquatic or terrestrial mammals.

The metabolic cost of flight in unrestrained birds

1978 ◽  
Vol 75 (1) ◽  
pp. 223-229 ◽  
Author(s):  
J. R. Torre-Bueno ◽  
J. Larochelle
Keyword(s):  
Carbon Dioxide ◽  
Metabolic Rate ◽  
Metabolic Cost ◽  
Large Change ◽  
Carbon Dioxide Production ◽  
The Body ◽  
Wingbeat Frequency ◽  
Bird Flight ◽  
Body Attitude ◽  
High Speeds

Oxygen consumption and carbon dioxide production were measured during flight in unrestrained starlings by a new method. Mean RQ after the first 30 min of flight was 0.69 +/− 0.08 (+/− S.D.). Mean rate of carbon dioxide production was 19.7 +/− 2.2 ml CO2/min, which corresponds to a metabolic rate of 8.9 +/− 1 W. Metabolic rate during flight did not change significantly over a range of air speeds from 8 to 18 m/s and birds would not fly at speeds outside of this range. Current theories of bird flight predict a large change in metabolic rate over the same range of speeds. Wingbeat frequency was constant at 12 +/− 0.5 Hz. Wingbeat amplitude reached a minimum at a speed of 14 m/s and increased at both higher and lower speeds. Angle between the body and horizontal was least at high speeds and increased at low speeds. As existing theories do not take into account the change of drag resulting from changes in body attitude, this may be a cause of the discrepancies between theory and observation.

Viral Susceptibility and Embryonic Differentiation.

Development ◽  
1963 ◽  
Vol 11 (4) ◽  
pp. 757-764
Author(s):  
Juhani Rapola ◽  
Tapani Vainio ◽  
Lauri Saxén
Keyword(s):  
Tissue Culture ◽  
Viral Replication ◽  
Metabolic Rate ◽  
Tissue Damage ◽  
Embryonic Tissue ◽  
High Metabolic Rate ◽  
Viral Susceptibility ◽  
Proliferative Rate ◽  
Active Proliferation ◽  
Severe Tissue

The fact that viral susceptibility changes during embryogenesis has been pointed out by both experimental embryologists and clinical practitioners, not to mention virologists working with avian material. In attempts to find the fundamental factors which make embryonic tissue susceptible or resistant to a given virus, the metabolic and proliferative rate have been considered relevant (Williamson et al., 1953; Robertson et al., 1955; Töndury, 1956). Experience accumulated in studies of the replication of various viruses in tissue culture has taught us that a high metabolic rate and active proliferation may not always enhance viral replication (Ginsberg, 1958). However, there seems to be justification for the view that an injurious agent leads to more severe tissue damage when it exercises its effect upon actively proliferating tissues than when it does so at the ‘resting stage’.

Breathing in brief exercise

1960 ◽  
Vol 15 (4) ◽  
pp. 583-588 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Metabolic Cost ◽  
Carbon Dioxide Tension ◽  
Minute Volume ◽  
Carbon Dioxide Output ◽  
Respiratory Minute Volume ◽  
Before And After

Two men ran for 20 or 60 seconds while inhaling air, oxygen or 4% carbon dioxide. Inspired respiratory minute volume was determined for each breath. Ventilation increased suddenly in the first breath with minimal changes in end-expiratory carbon dioxide tension and respiratory exchange ratio to a rate that remained constant for 20 seconds before increasing further. The rate of carbon dioxide output was uniform during the first 20 seconds. A 12% grade did not increase ventilation or oxygen uptake during runs of 20 seconds, but in the first minute of recovery, ventilation was 64% greater than after level runs. Inhalation of oxygen inhibited ventilation by 24% in the 20-second periods before and after the end of a 60-second run. Inhalation of carbon dioxide begun at rest produced increments in ventilation and end-expiratory carbon dioxide tension that varied little during running and recovery. In the 20-second runs ventilation varied with speed but appeared independent of ultimate metabolic cost. Submitted on January 21, 1960

Broad oxygen tolerance in the nematode Caenorhabditis elegans

2000 ◽  
Vol 203 (16) ◽  
pp. 2467-2478 ◽  
Author(s):  
W.A. Van Voorhies ◽  
S. Ward
Keyword(s):  
Caenorhabditis Elegans ◽  
Metabolic Rate ◽  
Developmental Stages ◽  
Small Body ◽  
Metabolic Cost ◽  
Soil Nematode ◽  
Nematode Caenorhabditis Elegans ◽  
Oxygen Levels ◽  
C Elegans ◽  
Short Period

This study examined the effects of oxygen tensions ranging from 0 to 90 kPa on the metabolic rate (rate of carbon dioxide production), movement and survivorship of the free-living soil nematode Caenorhabditis elegans. C. elegans requires oxygen to develop and survive. However, it can maintain a normal metabolic rate at oxygen levels of 3.6 kPa and has near-normal metabolic rates at oxygen levels as low as 2 kPa. The ability to withstand low ambient oxygen levels appears to be a consequence of the small body size of C. elegans, which allows diffusion to supply oxygen readily to the cells without requiring any specialized respiratory or metabolic adaptations. Thus, the small size of this organism pre-adapts C. elegans to living in soil environments that commonly become hypoxic. Movement in C. elegans appears to have a relatively minor metabolic cost. Several developmental stages of C. elegans were able to withstand up to 24 h of anoxia without major mortality. Longer periods of anoxia significantly increased mortality, particularly for eggs. Remarkably, long-term exposure to 100 % oxygen had no effect on the metabolic rate of C. elegans, and populations were able to survive for a least 50 generations in 100 % (90 kPa) oxygen. Such hyperoxic conditions are fatal to most organisms within a short period.

The metabolic rate and thermal conductance of the eastern barred bandicoot (Perameles gunnii) at different ambient temperatures

2003 ◽  
Vol 51 (6) ◽  
pp. 603 ◽  
Author(s):  
M. P. Ikonomopoulou ◽  
R. W. Rose
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Thermal Conductance ◽  
The Body ◽  
High Metabolic Rate ◽  
Ambient Temperatures ◽  
Reduced Body ◽  
Thermoneutral Zone ◽  
Reproductive Females

We investigated the metabolic rate, thermoneutral zone and thermal conductance of the eastern barred bandicoot in Tasmania. Five adult eastern barred bandicoots (two males, three non-reproductive females) were tested at temperatures of 3, 10, 15, 20, 25, 30, 35 and 40°C. The thermoneutral zone was calculated from oxygen consumption and body temperature, measured during the daytime: their normal resting phase. It was found that the thermoneutral zone lies between 25°C and 30°C, with a minimum metabolic rate of 0.51 mL g–1 h–1 and body temperature of 35.8°C. At cooler ambient temperatures (3–20°C) the body temperature decreased to approximately 34.0°C while the metabolic rate increased from 0.7 to 1.3 mL g–1�h–1. At high temperatures (35°C and 40°C) both body temperature (36.9–38.7°C) and metabolic rate (1.0–1.5 mL g–1 h–1) rose. Thermal conductance was low below an ambient temperature of 30°C but increased significantly at higher temperatures. The low thermal conductance (due, in part, to good insulation, a reduced body temperature at lower ambient temperatures, combined with a relatively high metabolic rate) suggests that this species is well adapted to cooler environments but it could not thermoregulate easily at temperatures above 30°C.

scholarly journals Metabolic cost of generating muscular force in human walking: insights from load-carrying and speed experiments

2003 ◽  
Vol 95 (1) ◽  
pp. 172-183 ◽  
Author(s):  
Timothy M. Griffin ◽  
Thomas J. Roberts ◽  
Rodger Kram
Keyword(s):  
Metabolic Rate ◽  
Stance Phase ◽  
Metabolic Cost ◽  
Direct Proportion ◽  
Muscular Force ◽  
Active Muscle ◽  
Cost Coefficient ◽  
Load Carrying ◽  
Leg Muscle ◽  
The Cost

We sought to understand how leg muscle function determines the metabolic cost of walking. We first indirectly assessed the metabolic cost of swinging the legs and then examined the cost of generating muscular force during the stance phase. Four men and four women walked at 0.5, 1.0, 1.5, and 2.0 m/s carrying loads equal to 0, 10, 20, and 30% body mass positioned symmetrically about the waist. The net metabolic rate increased in nearly direct proportion to the external mechanical power during moderate-speed (0.5–1.5 m/s) load carrying, suggesting that the cost of swinging the legs is relatively small. The active muscle volume required to generate force on the ground and the rate of generating this force accounted for >85% of the increase in net metabolic rate across moderate speeds and most loading conditions. Although these factors explained less of the increase in metabolic rate between 1.5 and 2.0 m/s (∼50%), the cost of generating force per unit volume of active muscle [i.e., the cost coefficient ( k)] was similar across all conditions [ k = 0.11 ± 0.03 (SD) J/cm3]. These data indicate that, regardless of the work muscles do, the metabolic cost of walking can be largely explained by the cost of generating muscular force during the stance phase.

Sign in / Sign up

Export Citation Format

Share Document