Field Metabolic Rate, Water Flux, Food Consumption and Time Budget of Koalas, Phascolarctos Cinereus (Marsupialia: Phascolarctidae) in Victoria.

1985 ◽  
Vol 33 (5) ◽  
pp. 655 ◽  
Author(s):  
KA Nagy ◽  
RW Martin
Keyword(s):  
Metabolic Rate ◽  
Food Consumption ◽  
Time Budget ◽  
Metabolic Rates ◽  
Feeding Rates ◽  
Influx Rate ◽  
Phascolarctos Cinereus ◽  
Water Influx ◽  
Dry Food ◽  
Field Metabolic Rates

Doubly labelled water measurements in free-ranging adult koalas (9.2 kg) indicated that field metabolic rates averaged 0.434 ml CO2 g-�h-� (equivalent to 2090 kJ per animal per day, or 2.59 X basal metabolic rate). Females (7.8 kg) had significantly higher mass-specific metabolic rates than males (10.8 kg). Percentage apparent assimilation of dietary substances was 56% for dry matter, 52% for energy, 32% for nitrogen, and 66% for water. Feeding rates were about 222 g dry food per animal per day (equivalent to 510 g fresh food per animal per day) in both sexes. However, males had a higher water influx rate (475 ml per animal per day) than females (358 ml per animal per day), suggesting either that males selected more succulent food than females, or that males drank rainwater but females did not. Koalas consumed about twice as much dietary nitrogen as they required for maintenance. They maintained constant body masses, and (presumably) had balanced energy, water and nitrogen budgets during our 20-day study, while eating Eucalyptus ovata foliage. Koalas spent about 4.7 h eating, 4 min travelling, 4.8 h resting while awake and 14.5 h sleeping in a 24-h period. Their activity periods were not obviously restricted to periods of daylight or darkness, but were scattered through the 24 hours. In comparison with free-living, three-toed sloths Bradypus variegatus (4.08 kg) in central America, koalas had significantly higher mass-corrected field metabolic rates (391 kJ kg-0.75 day-� for koalas v.209 for sloths), water influx rates (69.9 ml kg-0.80 day-� for koalas v. 49.8 for sloths), and feeding rates (42.7 g dry food kg-0.75 day-� for koalas v. 21.2 for sloths). Unlike sloths, koalas did not bask in the morning sunshine, and one telemetered koala had a relatively constant body temperature over 24 h (c. 36�C), compared with daily variations between 30 and 38�C in sloths. Population food consumption (g dry food consumed ha-� day-�) was greater for koalas (681 v. 378 for sloths), and koalas consumed most of the leaf production of their preferred food species, E. ovata, which resulted in extensive defoliation of these trees. Although there is similarity in the ecological roles of koalas and sloths, their physiology and behaviour differ substantially.

Seasonal daily, daytime and night-time field metabolic rates in Arabian babblers (Turdoides squamiceps)

2002 ◽  
Vol 205 (22) ◽  
pp. 3571-3575 ◽  
Author(s):  
Avner Anava ◽  
Michael Kam ◽  
Amiram Shkolnik ◽  
A. Allan Degen
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Breeding Season ◽  
Seasonal Patterns ◽  
Metabolic Rates ◽  
Night Time ◽  
Doubly Labelled Water ◽  
Influx Rate ◽  
Water Influx ◽  
Field Metabolic Rates

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.

Seasonal-Variation in Water Flux, Field Metabolic-Rate and Food-Consumption of Free-Ranging Koalas (Phascolarctos-Cinereus)

1995 ◽  
Vol 43 (1) ◽  
pp. 59 ◽  
Author(s):  
WAH Ellis ◽  
A Melzer ◽  
B Green ◽  
K Newgrain ◽  
MA Hindell ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Water Flux ◽  
Energy Requirements ◽  
Metabolic Rates ◽  
Feeding Rates ◽  
Phascolarctos Cinereus ◽  
Water Influx ◽  
Eucalyptus Crebra ◽  
Field Metabolic Rates ◽  
Free Ranging

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.

Field Metabolic Rates, Water Fluxes, and Feeding Rates of Quokkas, Setonix-Brachyurus, and Tammars, Macropus-Eugenii, in Western-Australia

1989 ◽  
Vol 37 (5) ◽  
pp. 553 ◽  
Author(s):  
KA Nagy ◽  
AJ Bradley ◽  
KD Morris
Keyword(s):  
Water Intake ◽  
Dry Matter ◽  
Feeding Rate ◽  
Metabolic Rates ◽  
Feeding Rates ◽  
Total Water ◽  
Water Influx ◽  
Field Metabolic Rates ◽  
Free Ranging ◽  
Total Water Intake

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.

Field Metabolic-Rate and Food Requirement of a Small Dasyurid Marsupial, Sminthopsis-Crassicaudata

1988 ◽  
Vol 36 (3) ◽  
pp. 293 ◽  
Author(s):  
KA Nagy ◽  
AK Lee ◽  
RW Martin ◽  
MR Fleming
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Water Flux ◽  
Metabolic Rates ◽  
Feeding Rates ◽  
Doubly Labelled Water ◽  
Sminthopsis Crassicaudata ◽  
Food Requirement ◽  
Field Metabolic Rates ◽  
Free Ranging

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.

Field Metabolic-Rate, Water Flux, and Food-Requirements of Short-Nosed Bandicoots, Isoodon-Obesulus (Marsupialia, Peramelidae)

1991 ◽  
Vol 39 (3) ◽  
pp. 299 ◽  
Author(s):  
KA Nagy ◽  
SD Bradshaw ◽  
BT Clay
Keyword(s):  
Metabolic Rate ◽  
Dry Matter ◽  
Produced Water ◽  
Water Flux ◽  
Pond Water ◽  
Doubly Labelled Water ◽  
Fresh Matter ◽  
Water Influx ◽  
Study Population ◽  
Field Metabolic Rates

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.

Coastal pH variability and the eco-physiological and behavioural response of a coastal fish species in light of future ocean acidification

2021 ◽  
Author(s):  
◽  
Carla Edworthy
Keyword(s):  
South Africa ◽  
Metabolic Rate ◽  
Continuous Monitoring ◽  
Activity Level ◽  
Metabolic Rates ◽  
Feeding Rates ◽  
Aerobic Scope ◽  
Carbonate Chemistry ◽  
Near Future

Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.

Resting and field metabolic rates of Awassi sheep and Baladi goats raised by Negev bedouin

2020 ◽  
Vol 158 (5) ◽  
pp. 431-437
Author(s):  
Michael Kam ◽  
Shaher El-Meccawi ◽  
Arieh Brosh ◽  
A. Allan Degen
Keyword(s):  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Arid Areas ◽  
Metabolic Rates ◽  
Herbaceous Vegetation ◽  
Sheep And Goats ◽  
Awassi Sheep ◽  
Natural Pasture ◽  
Field Metabolic Rates ◽  
The Cost

AbstractSheep are grazers and goats are intermediate feeders. By employing O2 consumption and heart rate measurements, resting metabolic rate (RMR) and field metabolic rate (FMR) were determined in four male fat-tailed Awassi sheep (44.0 ± 3.94) and four male Baladi goats (35.5 ± 5.42 kg) that were co-grazing natural pasture in the Negev Desert. There were 67.7 ± 3.75 g DM/m2 of herbaceous vegetation biomass, which was rapidly becoming senescent and more fibrous. We hypothesized that FMR of these desert-adapted ruminants would be relatively low when compared to other sheep and goat breeds, as animals in arid areas tend to have low metabolic rates. Both sheep (n = 6) and goats (n = 6) foraged 71% of the allotted 11 h free-pasture period; however, sheep grazed more than goats (P < 0.001); whereas goats browsed more than sheep (P < 0.001). RMR was higher (P = 0.007) in sheep than in goats (529 ± 23.5 v. 474 ± 25.4 kJ/kg0.75 BW/d), but FMR did not differ between species (618 ± 55.7 v. 613 ± 115.2 kJ/kg0.75 BW/d). In addition, the cost of activities, as a proportion of FMR, did not differ between sheep and goats; FMR increased by 89 kJ/kg0.75 BW/d or 17% in sheep and by 138 kJ/kg0.75 BW/d or 29% in goats. In comparing FMRs of sheep and goats in this study with these species in other studies, differences were inconsistent and, therefore, our hypothesis was not supported.

Comparative Field Energetics of Two Macropod Marsupials and a Ruminant.

1990 ◽  
Vol 17 (6) ◽  
pp. 591 ◽  
Author(s):  
KA Nagy ◽  
GD Sanson ◽  
NK Jacobsen
Keyword(s):  
Feeding Rate ◽  
Energy Content ◽  
Metabolizable Energy ◽  
Ecological Modelling ◽  
Feeding Rates ◽  
Doubly Labelled Water ◽  
Water Influx ◽  
Scaling Relationship ◽  
Field Metabolic Rates ◽  
Free Ranging

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.

Field Metabolic Rate and Water Flux of Nectarivorous Honeyeaters

1996 ◽  
Vol 44 (5) ◽  
pp. 445 ◽  
Author(s):  
WW Weathers ◽  
DC Paton ◽  
RS Seymour
Keyword(s):  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Low Cost ◽  
Water Flux ◽  
Doubly Labelled Water ◽  
Field Metabolic Rate ◽  
Influx Rate ◽  
Water Influx ◽  
Average Water ◽  
Foraging Tactic

Field metabolic rate (FMR) and water influx of New Holland honeyeaters (Phylidonyris novaehollandiae), eastern spinebills (Acanthorhynchus tenuirostris) and a crescent honeyeater (P. pyrrhoptera) were measured by the doubly labelled water technique. New Holland honeyeaters had just finished breeding and were beginning their summer moult. They ranged in mass from 15.4 to 21.0 g (mean = 17.3 g, n = 12) and had FMRs averaging 8.8 mt CO2 g(-1) h(-1) or 77.6 kJ day(-1), which was 2.8 times their measured basal metabolic rate (BMR). Their water influx rate averaged 10.7 mL day(-1). Eastern spinebills were still feeding young and had yet to begin moulting. They ranged in mass from 8.0 to 10.7 g (mean = 9.7 g, n = 6), had FMRs averaging 10.9 mL CO2 g(-1) h(-1) or 52.9 kJ day(-1) (2.5 times their measured BMR), and had an average water influx rate of 8.7 mL day(-1). FMR and water influx of a single 14.6-g crescent honeyeater, which was in late primary moult, were 75.9 kJ day(-1) (2.7 times measured BMR) and 12.5 mL day(-1). The FMR of New Holland honeyeaters varied inversely with mean standard operative temperature (T-es) calculated for values of T-es below 20 degrees C as follows: FMR (kJ day(-1)) = 134 - 5.47 T-es (n = 12, r(2) = 0.52). Honeyeater FMRs were much lower than would be predicted allometrically for hummingbirds of the same mass, reflecting the honeyeaters' low-cost foraging tactic of consuming nectar while perched.

scholarly journals Field metabolic rates of giant pandas reveal energetic adaptations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenlei Bi ◽  
Rong Hou ◽  
Jacob R. Owens ◽  
James R. Spotila ◽  
Marc Valitutto ◽  
...  
Keyword(s):  
Critical Temperature ◽  
Metabolic Rate ◽  
Grizzly Bears ◽  
Metabolic Rates ◽  
Giant Pandas ◽  
Fat Stores ◽  
Doubly Labeled Water Method ◽  
Field Metabolic Rates ◽  
Predicted Values

AbstractKnowledge of energy expenditure informs conservation managers for long term plans for endangered species health and habitat suitability. We measured field metabolic rate (FMR) of free-roaming giant pandas in large enclosures in a nature reserve using the doubly labeled water method. Giant pandas in zoo like enclosures had a similar FMR (14,182 kJ/day) to giant pandas in larger field enclosures (13,280 kJ/day). In winter, giant pandas raised their metabolic rates when living at − 2.4 °C (36,108 kJ/day) indicating that they were below their thermal neutral zone. The lower critical temperature for thermoregulation was about 8.0 °C and the upper critical temperature was about 28 °C. Giant panda FMRs were somewhat lower than active metabolic rates of sloth bears, lower than FMRs of grizzly bears and polar bears and 69 and 81% of predicted values based on a regression of FMR versus body mass of mammals. That is probably due to their lower levels of activity since other bears actively forage for food over a larger home range and pandas often sit in a patch of bamboo and eat bamboo for hours at a time. The low metabolic rates of giant pandas in summer, their inability to acquire fat stores to hibernate in winter, and their ability to raise their metabolic rate to thermoregulate in winter are energetic adaptations related to eating a diet composed almost exclusively of bamboo. Differences in FMR of giant pandas between our study and previous studies (one similar and one lower) appear to be due to differences in activity of the giant pandas in those studies.

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