Basal MetabolismEnergy MetabolismCalorimetry, IndirectBody WeightCharadriiformesOxygen ConsumptionBody CompositionEnergy IntakeBody SizeBody Temperature RegulationBirdsThermogenesisAcclimatizationCalorimetryBody TemperatureOxygen IsotopesMetabolismThyroid HormonesAnimal MigrationFeeding BehaviorObesityMammalsOrgan SizeLipid MetabolismPhysical ExertionNitrogenAdaptation, PhysiologicalEatingCold TemperatureNutritional RequirementsAdipose TissueExerciseTriiodothyronineModels, BiologicalSpecies SpecificityGlucoseTemperatureDietEnvironmentBody HeightBody Mass IndexBiological EvolutionRegression AnalysisDietary ProteinsSeasonsAnalysis of VarianceAgingMuscle, SkeletalCarbon DioxideTomography, Emission-ComputedOxygenBrainDeoxyglucosePhylogenyWater Loss, InsensibleSex FactorsFluorodeoxyglucose F18LiverHibernationDeoxy SugarsCerebrovascular CirculationFlight, AnimalDivingOxidation-ReductionLactic AcidGlycolysisRestKineticsRespiratory TransportTime FactorsLongevityFluorine RadioisotopesEstivationBiotransformationCarbon RadioisotopesBody ConstitutionReptilesSwimmingBlood GlucoseFatty AcidsInsulinMetabolic Networks and PathwaysMicrosomes, LiverRespirationLactatesCytochrome P-450 Enzyme SystemPositron-Emission TomographyPhysiology, ComparativeMagnetic Resonance SpectroscopyBoidaeFastingBody WaterMetabolic Clearance RateCarbon IsotopesDesert ClimateMitochondriaRadiopharmaceuticals