Field Energetics and Water Balance of Sugar Gliders, Petaurus Breviceps (Marsupialia:Petauridae).

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.

1990 ◽  
Vol 17 (6) ◽  
pp. 591 ◽  
Author(s):  
KA Nagy ◽  
GD Sanson ◽  
NK Jacobsen

Field metabolic rates (FMRs) and water influx rates were measured via the doubly labelled water method in wild Tasmanian pademelons and grey kangaroos living in the Jock Marshall Reserve at Clayton, Victoria, and in wild black-tailed deer free-ranging within a nature reserve at Davis, California. Deer expended more than 3 times more energy per day than similar sized grey kangaroos. Feeding rates required to achieve energy balance were estimated from FMRs along with an estimate of metabolizable energy content of the food. The estimated feeding rates for pademelons and kangaroos were combined with similar values for 5 other species of macropods to calculate an allometric (scaling) relationship for food requirements of macropod marsupials. Feeding rate had the following relationship to body mass: g food (DM) consumed per day = 0.20 g body mass0.79 (r2 = 0.94). The findings reported herein should be useful for predicting the approximate food requirements of free-ranging macropods and deer for purposes of ecological modelling, conservation efforts and management programmes.


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.


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.


2002 ◽  
Vol 205 (22) ◽  
pp. 3571-3575 ◽  
Author(s):  
Avner Anava ◽  
Michael Kam ◽  
Amiram Shkolnik ◽  
A. Allan Degen

SUMMARY Arabian babblers (Turdoides squamiceps; mean adult body mass=72.5 g) inhabit extreme deserts of Israel. Previous studies have shown that their daily field metabolic rates are similar in winter and summer and that there is an increase during the breeding season. We hypothesized that the difference in seasonal daily field metabolic rate would be a consequence of differences in daytime metabolic rate, and that night-time metabolic rate would be similar during the three seasons. We used doubly labelled water to determine daily,daytime and night-time field metabolic and water-influx rates in breeding babblers in spring and nonbreeding babblers in winter and summer. Daily and daytime energy expenditure rates were higher during the breeding season than during either summer or winter, but there was no difference among seasons in night-time energy expenditure rates. Thus, our hypothesis was supported. The daytime field metabolic rates in summer and winter nonbreeding babblers were 3.92× and 4.32× the resting metabolic rate (RMR),respectively, and in breeding babblers was 5.04× RMR, whereas the night-time field metabolic rates ranged between 1.26× RMR and 1.35× RMR in the three seasons. Daily and daytime water-influx rates were highest in winter, intermediate during the breeding season and lowest in summer, but there was no difference among seasons in night-time water-influx rate. Daytime water-influx rate was greater than night-time water-influx rate by 2.5-fold in summer, 3.9-fold in the breeding season and 6.75-fold in winter. Seasonal patterns of daily and daytime energy expenditure were similar, as were seasonal patterns of daily and daytime water influx. Daily and daytime energy expenditure and water-influx rates differed among seasons whereas night-time rates of both did not. Daily and daytime field metabolic rates of babblers were highest during the breeding season, whereas daily and daytime water-influx rates were highest in winter.


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.


1990 ◽  
Vol 17 (6) ◽  
pp. 641 ◽  
Author(s):  
G Dryden ◽  
B Green ◽  
D King ◽  
J Losos

The field metabolic rates and water influxes of Varanus acanthurus were determined by means of doubly-labelled water during late spring. The mean metabolic rate was 0.101 +/- 0.032 mL CO2 g-1 h-1, which was equivalent to an energy expenditure of 63 kJ kg-1 day-1 and a fresh food consumption rate of 13.2 g kg-1 day-1. The mean rate of water influx was 15.9 +/- 6.8 mL kg-1 day-1 and it is suggested that up to 30% of water influxes are via pulmo-cutaneous exchange and drinking. It is considered that V. acanthurus is a secretive 'sit and wait' predator and that this accounts for the lower than predicted water influx and metabolic rates of this species.


1991 ◽  
Vol 39 (3) ◽  
pp. 299 ◽  
Author(s):  
KA Nagy ◽  
SD Bradshaw ◽  
BT Clay

Field metabolic rates (FMRS) and water influx rates of free-living short-nosed bandicoots (Isoodon obesulus) were measured via the doubly labelled water technique. Bandicoots ranging in body mass from 775 to 1825 g (mean = 1230 g) had FMRS averaging 0.908 mL CO2 g-1 h-1, or 644 kJ d-1. This is about 2.7 times predicted basal metabolic rate. Water influx rates during the autumn measurement period were comparatively low, averaging 88.8 mL kg-1 d-1, or 103 mL d-1 for a 1230 g animal. Feeding rate (dry matter intake) was estimated to be 45 g d-1, assuming that the food was half invertebrates and half plant tissues (dry matter basis). Performed and metabolically produced water from the food can completely account for total water intake, indicating that bandicoots did not drink the rainwater or pond water that was available. The study population (estimated density = 0.63 bandicoots ha-1) consumed food at a rate of about 62 g fresh matter ha-1 d-1 (equivalent to 27 g dry matter or 605 kJ ha-1 d-1), which is similar to the food requirements of populations of small eutherian and marsupial insectivores in other habitats.


2008 ◽  
Vol 22 (2) ◽  
pp. 245-254 ◽  
Author(s):  
C. E. Sparling ◽  
D. Thompson ◽  
M. A. Fedak ◽  
S. L. Gallon ◽  
J. R. Speakman

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.


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