Comparisons of body size, field energetics, and water flux among populations of the skink Chalcides sexlineatus

1992 ◽  
Vol 70 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
R. P. Brown ◽  
R. S. Thorpe ◽  
J. R. Speakman
Keyword(s):  
Body Size ◽  
Energy Expenditure ◽  
Arid Zone ◽  
Small Body ◽  
Water Flux ◽  
Doubly Labelled Water ◽  
Northern Areas ◽  
Latitudinal Patterns ◽  
Microgeographic Variation ◽  
Study Sites

Within-island microgeographic variation in body size of the Gran Canarian skink, Chalcides sexlineatus, is described. Clear latitudinal patterns of variation were found for both males and females. Using Mantel tests we rejected within-island altitude-related ecological variation as the cause of the geographic variation, but found a significant relationship between body size and the pattern of lush–arid variation. Larger body size was found in populations from the lusher northern areas, and small body size in populations from the arid south. Studies with doubly labelled water showed higher energy expenditure per animal in a studied northern population than in a southern population, due to larger body size in the former. Mean mass-specific energy expenditure was found to be low in this species compared with other lizards, and did not differ significantly between populations (north, 150.1 J∙g−0.80∙d−1; south, 124.7 J∙g−0.80∙d−1). Mean mass-specific water fluxes were similar for lizards at both study sites (14.79 and 14.20 mL H2O∙kg−0.91∙d−1, respectively). Previous explanations invoking differences in water stress as the cause of variation in body size among populations of arid-zone lizards do not appear to be applicable to C. sexlineatus.

scholarly journals Energy expenditure of free-living reindeer estimated by the doubly labelled water method

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 211 ◽  
Author(s):  
Geir Gotaas ◽  
Eric Milne ◽  
Paul Haggarty ◽  
Nicholas J.C. Tyler
Keyword(s):  
Energy Expenditure ◽  
Rangifer Tarandus ◽  
Water Flux ◽  
Co2 Production ◽  
Wild Ungulates ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Svalbard Reindeer ◽  
Mountain Pasture ◽  
The Mean

The doubly labelled water (DLW) method was used to measure total energy expenditure (TEE) in three male reindeer (Rangifer tarandus tarandus) aged 22 months in winter (February) while the animals were living unrestricted at natural mountain pasture in northern Norway (69°20'N). The concentrations of 2H and l8O were measured in water extracted from samples of faeces collecred from the animals 0.4 and 11.2 days after injection of the isotopes. Calculated rates of water flux and CO2-production were adjusted to compensate for estimated losses of 2H in faecal solids and in methane produced by microbial fermentation of forage in the rumen. The mean specific TEE in the three animals was 3.057 W.kg-1 (range 2.436 - 3.728 W.kg1). This value is 64% higher than TEE measured by the DLW method in four captive, non-pregnant adult female reindeer in winter and probably mainly reflects higher levels of locomotor activity in the free-living animals. Previous estimates of TEE in free-living Rangifer in winter based on factorial models range from 3.038 W.kg-1 in female woodland caribou (R. t. caribou) to 1.813 W.kg-1 in female Svalbard reindeer (R. t. platyrhynchus). Thus, it seems that existing factorial models are unlikely to overestimate TEE in reindeer/caribou: they may, instead, be unduly conservative. While the present study serves as a general validation of the factorial approach, we suggest that the route to progress in the understanding of field energetics in wild ungulates is via application of the DLW method.

scholarly journals Field Metabolism and Water Flux of Carolina Chickadees During Breeding and Nonbreeding Seasons: A Test of the “Peak-Demand” and “Reallocation” Hypotheses

The Condor ◽  
2001 ◽  
Vol 103 (2) ◽  
pp. 370-375 ◽  
Author(s):  
Paul F. Doherty ◽  
Joseph B. Williams ◽  
Thomas C. Grubb
Keyword(s):  
Body Size ◽  
Energy Expenditure ◽  
Breeding Season ◽  
Water Flux ◽  
Doubly Labeled Water ◽  
Peak Demand ◽  
Nonbreeding Season ◽  
Poecile Carolinensis ◽  
Northern Edge ◽  
Carolina Chickadees

AbstractWe tested the “peak-demand” and “reallocation” hypotheses of seasonal energy expenditure which predict, respectively, that energy expenditure is greatest during the breeding season or varies little seasonally. We tested these predictions by utilizing the doubly labeled water technique to estimate energy expenditure and water flux of Carolina Chickadees (Poecile carolinensis) in both the breeding and nonbreeding seasons. Similar to Weathers et al. (1999), we did not find support for either of these hypotheses, finding instead that energy expenditure was greater during the nonbreeding season. The fact that our study site was at the northern edge of the species' range, where winters are severe, may have influenced this result. Comparisons with other parid studies were equivocal because body size was an important factor in explaining seasonal energetics, and only the larger species have been examined during the breeding season.

Water and Energy Balance of Captive and Free-Ranging Spinifexbirds (Eremiornis Carteri) North (Aves:Sylviidae) on Barrow Island, Western Australia

1996 ◽  
Vol 44 (2) ◽  
pp. 107 ◽  
Author(s):  
SJ Ambrose ◽  
SD Bradshaw ◽  
PC Withers ◽  
DP Murphy
Keyword(s):  
Body Mass ◽  
Arid Zone ◽  
Water Flux ◽  
Thermal Conductance ◽  
Standard Metabolic Rate ◽  
Annual Rainfall ◽  
Doubly Labelled Water ◽  
Evaporative Water ◽  
Ambient Temperatures ◽  
The Mean

The mean annual rainfall of Barrow Island, located about 90 km north of Onslow off the arid Western Australian coast, is 324 mm, 74% of which falls as cyclonic rain between February and May. Spinifexbirds captured in May 1992 had a mean body mass of 12.3 +/- 0.3 g and a total body water content (TBW) of 774 +/- 1.6%. In December 1992 the mean body mass was significantly lower (11.7 +/- 0.2 g; P < 0.05), despite a TBW of 73.4 +/- 1.0%. Spinifexbirds maintained water balance in both seasons, but water flux rates were significantly higher in May (P = 0.01). Respective influx and efflux rates in May were 0.70 +/- 0.30 and 0.72 +/- 0.03 mL (g day)(-1) compared with 0.60 +/- 0.04 and 0.57 +/- 0.04 mL (g day)(-1) in December. Field metabolic rates (FMRs), measured with doubly-labelled water ((3)HH(18)0), did not differ significantly between the two periods. The mean FMR in May was 6.8 +/- 0.6 mL CO2 (g h)(-1) compared with 7.2 +/- 0.9 mL CO2 (g h)(-1) in December, similar to rates predicted by Nagy and Peterson (1988) for a similar-sized passerine. The thermoneutral zone (TNZ) of spinifexbirds, determined by metabolic laboratory trials in December, extended from 30 to 39 degrees C. The standard metabolic rate (SMR) within the TNZ was 2.9 +/- 0.1 mL O-2 (g h)(-1), which is up to 20% lower than predicted values. Body temperature was maintained at 39.1 degrees C in the TNZ, but birds became hyperthermic at ambient temperatures (T(a)s) higher than 35 degrees C, with body temperatures reaching 44 degrees C. Wet thermal conductance and evaporative water loss increased markedly at T(a)s > 35 degrees C. The data suggest that spinifexbirds have limited physiological adaptations to desert conditions compared with some other arid-zone birds.

scholarly journals The efficiency of food utilization, digestibility of foodstuffs and energy expenditure of mice selected for large or small body size

1962 ◽  
Vol 3 (1) ◽  
pp. 51-68 ◽  
Author(s):  
Ruth E. Fowler
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Energy Expenditure ◽  
Small Body ◽  
Energetic Efficiency ◽  
Food Utilization ◽  
Control Line ◽  
Small Body Size ◽  
Gross Efficiency ◽  
Body Activity

The efficiency of food utilization, the digestibility of foodstuffs, energy metabolism, and body activity have been studied in three lines of mice, one selected for large, another for small body size, and a third, control, line.The gross efficiency of food utilization was highest in the large line, intermediate in the control line and lowest in the small line between 21 and approximately 35 days of age. During this period, gross efficiency declined in the large and control lines with increasing size and decreasing growth-rate, presumably due to an increase in maintenance costs in comparison with the weight gained. In the small line, the efficiency of food utilization increased up to 35 days of age but declined thereafter. The energetic efficiency (measured in Calories) was higher in the large than in the small line up to 4 weeks of age, i.e. when the growth-rate was high, and after 6 weeks of age, when fat was being deposited at an increased rate.The increased efficiency of large mice was not entirely associated with a greater proportion of the ingested food being absorbed from the gut. Large mice absorbed a greater proportion of protein, though the difference was not sufficient to account for the large weight difference between the large and small lines.The energy expenditure of mice of the large line was greater than that of the small line at all ages and similar for the same body weights. The reduced growth-rate of small mice was not due to abnormally high or low energy costs. There was no evidence that body activity determined or restricted the rate of growth in either line.Mice selected for small size were phenotypically unlike pituitary dwarf mice, although the low nitrogen retention during the growing-period indicated a deficiency of some growth stimulus.

scholarly journals Estimation of energy expenditure in free-living red deer (Cervus elaphus) with the doubly-labelled water method

1998 ◽  
Vol 80 (3) ◽  
pp. 263-272 ◽  
Author(s):  
P. Haggarty ◽  
J. J. Robinson ◽  
J. Ashton ◽  
E. Milne ◽  
C. L. Adam ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Cervus Elaphus ◽  
Red Deer ◽  
Water Flux ◽  
Climatic Conditions ◽  
Free Living ◽  
Doubly Labelled Water ◽  
The Mean ◽  
Distribution Spaces ◽  
Living Adult

Energy expenditure was estimated using the doubly-labelled water (DLW) method in summer in five free-living adult, non-pregnant, non-lactating, red deer (Cervus elaphus) hinds (weight 107.3 (se 0.9) kg; age 6 (se 1) years) on lowland pasture under typical farming conditions. Climatic conditions were monitored throughout the experiment. Errors due to 2H losses in CH4 and faeces were calculated from previous estimates of stoichiometries. CH4 production, fractionated water loss, urinary N and O2 consumption were estimated using an iterative approach. The water flux (rH2O) in these animals consuming only fresh grass was 12 (se 0.5) kg/d, the CO2 production (rCO2) was 1271 (se 4.0) litres/d and the mean energy expenditure was 25 (se 0.8) MJ/d. There were no significant differences in the isotope distribution spaces and flux rates, rH2O, rCO2 or energy expenditure using the multi-point or two-point approaches to calculation. The DLW-derived energy expenditure of 25 MJ/d is approximately 20% higher than the recommended intake of 21 MJ/d for adult hinds kept outdoors (Adam, 1986) and, at 757 kJ/kg0.75 per d, one third higher than the value of 570 kJ/kg0.75 per d for stags penned indoors (Key et al. 1984).

Comparative water flux and daily energy expenditure of lizards of the genus Gallotia (Lacertidae) from the Canary Islands

1995 ◽  
Vol 16 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Marcos Baez ◽  
Roland Vernet ◽  
Jacques Castanet
Keyword(s):  
Energy Expenditure ◽  
Water Flux ◽  
Climatic Conditions ◽  
Daily Energy Expenditure ◽  
Water Fluxes ◽  
Water Turnover ◽  
Doubly Labelled Water ◽  
Water Influx ◽  
Daily Energy ◽  
Average Water

AbstractWater fluxes and daily energy expenditure (DEE) of Gallotia galloti, G. stehlini and G. atlantica, were estimated over a three-year period using the doubly-labelled water (DLW) method. Water influx varied little between seasons and between sexual categories. Juveniles tended to have higher water fluxes in spring in all three species; after a dry period the water turnover tended to decrease for all sexes in G. galloti and G. stehlini, whereas little variation was observed for G. atlantica. The average water influx, combined for all periods, was 46.27, 50.97 and 38.20 ml H2O.kg-1 d-1 for the three species respectively; only the last value differs significantly from the remaining two. The mean DEE, for all periods combined, were 189.7, 179.4 and 146.5 J g-1 d-1 for the three species respectively. As for water turnover, only the value for G. atlantica differed significantly. These data suggest that: G. atlantica may be better adaptated to maintain homeostasis during dry periods and that differences in interspecific DEE can also be explained by others factors than differences in habitat, climatic conditions, daily profiles of activity or body temperatures. We suspect that the incidence of intraspecific competition has more importance in G. atlantica than in the two other species.

Seasonal variation in energy expenditure, water flux and food consumption of Arabian oryx Oryx leucoryx

2001 ◽  
Vol 204 (13) ◽  
pp. 2301-2311 ◽  
Author(s):  
Joseph B. Williams ◽  
Stéphane Ostrowski ◽  
Eric Bedin ◽  
Khairi Ismail
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Body Mass ◽  
Water Loss ◽  
Arid Zone ◽  
Water Flux ◽  
Metabolic Rates ◽  
Free Living ◽  
Evaporative Water ◽  
Arabian Oryx

SUMMARY We report on the energy expenditure and water flux, measured in the laboratory and in the field, of the Arabian oryx Oryx leucoryx, the largest desert ruminant for which measurements of the field metabolic rate of free-living individuals have been made using doubly labeled water. Prior to extirpation of this species in the wild in 1972, conservationists sequestered a number of individuals for captive breeding; in 1989, oryx were reintroduced in Saudi Arabia into Mahazat as-Sayd (2244km2). Apart from small pools of water available after rains, oryx do not have free-standing water available for drinking and therefore rely on grasses that they eat for preformed water intake as well as their energy needs. We tested whether oryx have a reduced fasting metabolic rate and total evaporative water loss (TEWL) in the laboratory, as do some other arid-adapted mammals, and whether oryx have high field metabolic rates (FMRs) and water influx rates (WIRs), as predicted by allometric equations for large arid-zone mammals. We measured FMR and WIR during the hot summer, when plant moisture content was low and ambient temperatures were high, and after winter rains, when the water content of grasses was high. For captive oryx that weighed 84.1kg, fasting metabolic rate averaged 8980kJday−1, 16.7% lower than predictions for Artiodactyla. Our own re-analysis of minimal metabolic rates among Artiodactyla yielded the equation: logV̇O2=−0.153+0.758logM, where V̇O2 is the rate of oxygen uptake in lh−1 and M is body mass in kg. Fasting metabolic rate of oryx was only 9.1% lower than predicted, suggesting that they do not have an unusually low metabolic rate. TEWL averaged 870.0mlday−1, 63.9% lower than predicted, a remarkably low value even compared with the camel, but the mechanisms that contribute to such low rates of water loss remain unresolved. For free-living oryx, FMR was 11076kJday−1 for animals with a mean body mass of 81.5kg during summer, whereas it was 22081kJday−1 for oryx in spring with a mean body mass of 89.0kg, values that were 48.6% and 90.4% of allometric predictions, respectively. During summer, WIR averaged 1310mlH2Oday−1, whereas in spring it was 3438mlH2Oday−1. Compared with allometric predictions, WIR was 76.9% lower than expected in summer and 43.6% lower in spring. We found no evidence to support the view that the WIR of large desert ungulates is higher than that of their mesic counterparts. On the basis of the WIR of the oryx averaged over the year and the water contents of plants in their diet, we estimated that an oryx consumes 858kg of dry matter per year.

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