scholarly journals Accounting for body mass effects in the estimation of field metabolic rates from body acceleration

2021 ◽  
pp. jeb.233544
Author(s):  
Evan E. Byrnes ◽  
Karissa O. Lear ◽  
Lauran R. Brewster ◽  
Nicholas M. Whitney ◽  
Matthew J. Smukall ◽  
...  

Dynamic Body Acceleration (DBA), measured through animal-attached tags, has emerged as a powerful method for estimating field metabolic rates of free-ranging individuals. Following respirometry to calibrate oxygen consumption rate (MO2) with DBA under controlled conditions, predictive models can be applied to DBA data collected from free-ranging individuals. However, laboratory calibrations are generally performed on a relatively narrow size range of animals, which may introduce biases if predictive models are applied to differently sized individuals in the field. Here, we tested the mass dependence of the DBA-MO2 relationship to develop an experimental framework for the estimation of field metabolic rates when organisms differ in size. We performed respirometry experiments with individuals spanning one order of magnitude in body mass (1.74–17.15 kg) and used a two-stage modelling process to assess the intraspecific scale dependence of the MO2-DBA relationship and incorporate such dependencies into the coefficients of MO2 predictive models. The final predictive model showed scale dependence; the slope of the MO2-DBA relationship was strongly allometric (M1.55), whereas the intercept term scaled closer to isometry (M1.08). Using bootstrapping and simulations, we evaluated the performance of this coefficient-corrected model against commonly used methods of accounting for mass effects on the MO2-DBA relationship and found the lowest error and bias in the coefficient-corrected approach. The strong scale dependence of the MO2-DBA relationship indicates that caution must be exercised when models developed using one size class are applied to individuals of different sizes.

2020 ◽  
Author(s):  
Evan E. Byrnes ◽  
Karissa O. Lear ◽  
Lauran R. Brewster ◽  
Nicholas M. Whitney ◽  
Matthew J. Smukall ◽  
...  

ABSTRACTLife history, reproduction, and survival are fundamentally linked to energy expenditure and acquisition. Dynamic Body Acceleration (DBA), measured through animal-attached data-loggers or transmitters, has emerged as a powerful method for estimating field metabolic rates of free-ranging individuals. After using respirometry to calibrate oxygen consumption rate with DBA in captive settings, predictive models can be applied to DBA data collected from free-ranging individuals. However, laboratory calibrations are generally performed on a narrow size range of animals, which may introduce biases when predictive models are applied to differently sized individuals in the field. Here, we tested the influence of scale effects on the ability of a single predictive model to predict over a range of body sizes. We performed respirometry experiments with individuals spanning one order of magnitude in body mass (1.74–17.15 kg) and used a two-step modelling process to assess the intra-specific scale dependence of the -DBA relationship and incorporate such dependencies into the covariates of predictive models. The final predictive model showed scale dependence; the slope of the -DBA relationship was strongly allometric (M1.55), whereas the intercept term scaled closer to isometry (M1.08). Using bootstrapping and simulations, we tested the performance of this covariate-corrected model against commonly used methods of accounting for mass effects on the -DBA relationship and found lowest error and bias in the covariate-corrected approach. The strong scale dependence of the -DBA relationship indicates that caution must be exercised when models developed using one size class are applied to individuals of different sizes.Summary statementThe relationship between oxygen consumption rate and dynamic body acceleration is allometrically dependent, and models incorporate different slope and intercept scaling rates estimate metabolic rates more accurately than mass-specific approaches.


1988 ◽  
Vol 36 (3) ◽  
pp. 293 ◽  
Author(s):  
KA Nagy ◽  
AK Lee ◽  
RW Martin ◽  
MR Fleming

Field metabolic rates (FMRs) and rates of water flux in free-ranging fat-tailed dunnarts, Sminthopsis crassicaudata, were measured during spring (late October) using doubly labelled water. Feeding rates were estimated on the basis of water and energy fluxes. FMRs averaged 68.7 kJ d-' in adults (mean body mass= 16.6 g), and were 29.2 kJ d-' in juveniles (6.1 g). These FMRs are 6.6 times basal metabolic rate (BMR), and are much higher than the hypothetical maxima of four to five times BMR. Other dasyurid marsupials also have high FMR/BMR ratios, but so does a small petaurid marsupial. S. crassicaudata consumed 80-90% of its body mass in arthropods each day. The diet of arthropods apparently provided enough water for the animals to maintain water balance without drinking during this study.


1982 ◽  
Vol 60 (6) ◽  
pp. 1412-1416 ◽  
Author(s):  
Justin D. Congdon ◽  
Donald W. Tinkle

Metabolic rates of free-ranging Sceloporus graciosus (Sauria: Iguanidae) were measured during the summer using doubly labeled H2O. Adults of either sex and juveniles did not differ in field metabolic rates (0.26 mL CO2∙g−1∙h−1or 160 J∙g−1∙day−1). Field metabolic rates were 2.4 times the resting metabolic rate, and activity respiration was 3.1 times the resting metabolic rate at lizard activity temperatures. Activity accounted for 59% of the energy consumption due to respiration. Calculated rates of feeding indicated a 415 J∙day−1 deficit in metabolizable energy intake, and this was reflected in rate of loss of body mass throughout the study. Daily energy harvested by 200 lizards (31 kJ∙day−1), which approximates densities (per hectare) on the study area, would supply only 40% of the daily energy requirements of one insectivorous bird with similar body mass and activity level of a Phainopepla (79 kJ∙day−1).


1989 ◽  
Vol 37 (5) ◽  
pp. 553 ◽  
Author(s):  
KA Nagy ◽  
AJ Bradley ◽  
KD Morris

Field metabolic rates (FMRS) and water influx rates were measured by means of doubly labelled water in free-ranging quokkas living on Rottnest I, and free-ranging tammar wallabies living on Garden I. Feeding rates were estimated from energy requirements. Quokkas ranging in body mass from 1.44 to 2.83 kg (mean 1.90 kg) had FMRS averaging 0.574 mL C02 (g.h)-', which is equivalent to 548 kJ d-'. Their rates of total water intake averaged 47.3 mL (kg.d)-', or 90.5 mL d-'. Estimated feeding rate was 54.8 g (dry matter) per day, and water ingested as part of the food (preformed and metabolically produced) can completely account for total water intake. We believe that quokkas did not drink water during our field measurements. Tammars ranging in body mass from 3.20 to 6.35 kg (mean 4.38 kg) had FMRS averaging 0.518 mL CO2 (g.h)-', which is equivalent to 1150 kJ d-'. Their rates of water influx averaged 57.5 mL (kg.d)-', or 270 mL d-', and their estimated feeding rate was 115 g (dry matter) per day. Tammars also probably did not drink free-standing water during our study. FMRs of quokkas averaged 1 .80 x basal metabolic rate (BMR), and FMRS of tammars averaged 1.87 x BMR; this difference is not significant. We estimate that the 5000 quokkas on Rottnest I. consume at least 100 000 kg of plant matter (dry mass) per year, and the 2173 tammars on Garden I. ingest more than 90 000 kg. Measurements of food availability are needed to permit evaluation of the relationship between food supply and demand for these two populations of macropod marsupials.


1999 ◽  
Vol 77 (11) ◽  
pp. 1838-1842 ◽  
Author(s):  
Yutaka Watanuki ◽  
Alan E Burger

Interspecific allometric equations for dive duration were calculated for two groups of wing-propelled divers: penguins, which specializing in diving, and alcids, which balance demands for aerial flying with those of diving. The equations for maximum dive duration (min) were 1.433M0.702 and 3.612M0.735 (where M is body mass in kilograms) for penguins (10 species) and alcids (9 species), respectively, hence did not support a simple oxygen store/usage hypothesis based on the prediction that the mass exponent of aerobic dive limit is close to 0.25. Equations for feeding dives were 0.569M0.712 and 1.094M0.391 in penguins (9 species) and alcids (10 species), respectively. The allometric exponent for the duration of feeding dives for penguins did not match the predicted value of 0.25, but that for alcids did not differ significantly from this value. Alcids exhibited a maximum dive duration 2.5 times longer than that for penguins after mass effects were controlled for. The size of oxygen stores and metabolic rates based on laboratory studies of penguins and alcids failed to explain the longer dive duration in alcids than in penguins.


1995 ◽  
Vol 43 (1) ◽  
pp. 59 ◽  
Author(s):  
WAH Ellis ◽  
A Melzer ◽  
B Green ◽  
K Newgrain ◽  
MA Hindell ◽  
...  

Mass-corrected field metabolic rates of free-ranging male koalas in central Queensland, Australia, varied between 0.329 MJ kg0.75 day-1 in summer and 0.382 MJ kg0.75 day-1 in winter. Field water influx measured 50.8 mL kg-0.8 day-1 in winter, increasing to 59.9 mL kg0.8 day-1 in summer for the same koalas, and was positively correlated with values for leaf moisture of food. Winter rates of water influx for koalas from Springsure were lower than those recorded for koalas from Victoria for the same period of the year. Mass-corrected feeding rates were lower in summer than winter; wet food intake was significantly lower than reported for similar sized female koalas from Victoria. The preferred browse was Eucalyptus crebra in winter and E. tereticornis in summer. Our study indicates that in central Queensland seasonal changes in diet selection by male koalas reflect increased energy requirements in winter and increased water requirements in summer.


1985 ◽  
Vol 33 (5) ◽  
pp. 683 ◽  
Author(s):  
KA Nagy ◽  
GC Suckling

Doubly labelled water measurements in free-ranging sugar gliders (Petaurus breviceps) weighing 121 g indicated that field metabolic rates (FMRS) averaged 62.5 litres CO2/kg daily, equivalent to 169 kJ per animal daily (3.8 times basal metabolic rate). The females, most of which had small pouch young, weighed significantly less than males (112 g compared with 135 g), but mass-specific FMRS did not differ significantly between sexes. Rates of water influx (mass-specific) also did not differ between sexes, and were 208 ml/kg daily. The diet consisted of about two-thirds acacia gum, one-third mixed arthropods and traces of bark (on a dry mass basis). Apparent assimilation of dietary substances was 88% for DM, 89% for energy, 86% for nitrogen and 61% for water. Gliders consumed 11.2 g DM of food daily. The diet contained 44% water (fresh mass basis), and provided about half of the water gliders obtained. The other half presumably was ingested as rainwater. In comparison with the ecologically similar Leadbeater's possums (129 g), sugar gliders had lower metabolic rates while active outside their nests (17.4 compared with 31.4 kJ/h for the possums), primarily because possums spent energy for activity 2.5 times faster than did sugar gliders. This suggests that gliding affords sugar gliders a considerable energetic saving, but portion of time abroad spent foraging and resting, and distribution, abundance and predictability of food resources may also account for this difference.


1975 ◽  
Vol 63 (1) ◽  
pp. 273-293 ◽  
Author(s):  
S. P. Thomas

The energetic cost of flight in a wind-tunnel was measured at various combinations of speed and flight angle from two species of bats whose body masses differ by almost an order of magnitude. The highest mean metabolic rate per unit body mass measured from P. hastatus (mean body mass, 0.093 kg) was 130.4 Wkg-1, and that for P. gouldii (mean body mass, 0.78 kg) was 69.6 Wkg-1. These highest metabolic rates, recorded from flying bats, are essentially the same as those predicted for flying birds of the same body masses, but are from 2.5 to 3.0 times greater than the highest metabolic rates of which similar-size exercising terrestrial mammals appear capable. The lowest mean rate of energy utilization per unit body mass P. hastatus required to sustain level flight was 94.2 Wkg-1 and that for P. gouldii was 53.4 Wkg-1. These data from flying bats together with comparable data for flying birds all fall along a straight line when plotted on double logarithmic coordinates as a function of body mass. Such data show that even the lowest metabolic requirements of bats and birds during level flight are about twice the highest metabolic capabilities of similar-size terrestrial mammals. Flying bats share with flying birds the ability to move substantially greater distance per unit energy consumed than walking or running mammals. Calculations show that P. hastatus requires only one-sixth the energy to cover a given distance as does the same-size terrestrial mammal, while P. gouldii requires one-fourth the energy of the same-size terrestrial mammal. An empirically derived equation is presented which enables one to make estimates of the metabolic rates of bats and birds during level flight in nature from body mass data alone. Metabolic data obtained in this study are compared with predictions calculated from an avian flight theory.


Ecoscience ◽  
1996 ◽  
Vol 3 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Donald W. Thomas ◽  
R. Mark Brigham ◽  
Hélène Lapierre

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