Towards Accurate Calculation of Field Metabolic Rates for Bats R.D. (Bob) Bullen Bat Call WA Pty Ltd 13 July 2017

Bat FMR Modelling - Objective A BALANCED ENERGY BUDGET IS THE KEY TO AN ANIMALS ABILITY TO SURVIVE AND REPRODUCE UNDERSTANDING THIS BUDGET for a flying animal IS A VERY DIFFICULT CHALLENGE ESTIMATES FOR BATS BASED ON SCALING MASS IS TYPICALLY ACCURATE TO +/- 50% FOR INTRA AND INTER-SPECIES ENERGY BUDGET ASSESSMENTS FOR BATS IN GUILDS, COMMUNITIES AND ALSO AT CONTINENTAL LEVEL, ACCURACY OF BETTER THAN 10% IS NEEDED.

Bat FMR Modelling – Mass Scaling

Bat FMR Modelling - Strategy TO ACHIEVE ESTIMATES WITHIN 10% OF FIELD DATA IT IS NECESSARY TO MODEL ACCURATELY THE VARIOUS PROCESS THAT MAKE UP THE ENERGY BUDGET. IT IS RECOGNISED (SEE SPEAKMAN AND RACEY 2003) THAT FMR CAN BE ESTIMATED USING TIME-ENERGY BUDGETS (TEBs) AND THAT THESE ESTIMATES PROVIDE PARTITIONING BETWEEN DIFFERENT THERMOREGULATORY AND PHYSICAL ACTIVITIES BUT EARLY ATTEMPTS PROVIDED ACCURACIES NO BETTER THAN SIMPLE SCALING RELATIONSHIPS. MY METHOD COMBINES THE ACCURATE CALCULATION OF A BATS METABOLIC POWER LEVEL DURING SEVERAL FLIGHT PHASES, E.G. COMMUTING AND FORAGING, AND COMBINES THIS WITH ESTIMATES OF ENERGY CONSUMED DURING OTHER PHASES OF A DAILY CYCLE. IT REQUIRES ON AN ACCURATE TEB AS A BASIS OF THE CALCULATION.

Bat FMR Modelling - TEB TEBs FOR FIVE DIFFERENT FORAGING STRATEGIES HAVE BEEN DISTILLED USING BOTH PUBLISHED DATA AND OUR OWN OBSERVATIONS. THESE STRATEGIES ARE: INSECTIVOROUS BATS SMALL NECTARIVORES, OMNIVORES AND FRUGIVORES UNDER 40 G LARGE NECTARIVORES, OMNIVORES AND FRUGIVORES OVER 40 G LARGE CARNIVORES OVER 50 G SANGUINIVORES

Bat FMR Modelling – TEB EXAMPLE TEB FOR COMMON INSECTIVOROUS SPECIES   Adult male and non-repro adult female (hours) Pregnant Female Lactating Day Roost Inactive (default is DTMR @5% BMR) 8 Day Roost Active at RMR = 130% BMR 10.5 18 Night Roosting at 130% BMR 3 ( 0 – 3 ) 0.5 Time Commuting at Vsan 0.5 typical (0 - 1) Time Foraging at Vae with power @ 115% to allow for manoeuvre, catch and carry costs. 2 ( 1.5 – 3) 2.5 5.0 ( 4 to 6 )

Bat FMR Modelling BASIC ECOLOGICAL INFORMATION FOR THE SPECIES IS NEEDED BASIC MORPHOLOGICAL DATA MASS – WING AREA – WING SPAN – GOOD QUALITY IMAGE FORAGING STRATEGY FORAGING MICROHABITAT TROPICAL OR TEMPERATE GEOGRAPHIC SPREAD THE ABILITY TO HOVER PREFERENCE FOR A CAVE OR TREE/BUILDING ROOST PRIMARY FOOD PREFERENCE – INSECTS, NECTAR, ETC.

Bat FMR Modelling PHYSIOLOGICAL DATA PARAMETERS TO APPLY DIRECTLY TO FMR ESTIMATES ARE ALL EITHER KNOWN (MEASURED FOR THE SPECIES) OR CALCULATED FROM THE ECOLOGICAL DATA BASAL METABOLIC RATE - BMR MUSCULOSKELETAL MECHANICAL EFFICIENCY HEART MASS BLOOD HAEMOGLOBIN EFICIENCY OF CIRCULATORY AND BREATHING SYSTEMS FLIGHT MUSCLE MASS USE OF TORPOR

Bat FMR Modelling CHARACTERISTIC FLIGHT SPEEDS AND POWER POLARS FIVE CHARACTERIASTIC FLIGHT SPEEDS ARE CALCULATED USING THE METHOD OF BULLEN et al. (2016). MINIMUM SPEED – VMIN EFFICIENT SPEED RANGE – VEFF MAXIMUM AEROBIC SPEED – VAE SUSTAINABLE ANEROBIC SPEED – VSAN MAXIMUM ANEROBIC SPEED – VMAN FMR CALC. TYPICALLY USES THE MIDDLE THREE

Bat FMR Modelling CHARACTERISTIC FLIGHT SPEEDS AND POWER POLARS FOR MOST SPECIES METABOLIC POWER IS CALCULATED FOR THE THREE FLIGHT SPEEDS VEFF(UPPER), VAE and VSAN FOR A FEW SPECIES WITH UNUSUAL FORAGING STRATEGIES VMIN AND VEFF(LOWER) ARE NEEDED e.g. Vampire bat (D. rotundus). VEFF(UPPER) IS USED BY LARGE OMNIVORES, FRUGIVORES AND CARNIVORES VAE IS USED BY INSECTIVORES AND SMALL OMNIVORES DURING FORAGING VSAN IS USED BY INSECTIVORES WHILE COMMUTING.

Bat FMR Modelling CHARACTERISTIC FLIGHT SPEEDS AND POWER POLARS

Bat FMR Modelling COMBINING TEB AND POWER POLAR DAILY CYCLE OF EACH GROUP IS BROKEN INTO FIVE ELEMENTS INACTIVE DIURNAL ROOSTING WHILE TORPID ACTIVE DIURNAL ROOSTING WHILE NORMOTHERMIC NOCTURNAL ROOSTING WHILE NORMOTHERMIC COMMUTING FLIGHT FORAGING FLIGHT CONTRIBUTIONS DUE TO PREGNANCY AND LACTATION ARE REQUIRED

Bat FMR Modelling PUBLISHED EMPERICAL FMR DATA FROM THE LITERATURE WE HAVE DISTILLED RELIABLE FMR DATA FOR 16 SPECIES THESE ARE ALL DOUBLY LABELLED WATER (DLW) DATA FROM FREE LIVING OR RECENTLY CAUGHT BATS IN CONTROLLED LABORATORY CONDITIONS.

Bat FMR Modelling FMR components – Air superiority insectivore

Bat FMR Modelling COMPARISON OF EMPERICAL DATA WITH MODELLED RESULTS INSECTIVORES – SIX SPECIES NON-REPRODUCTIVE AVERAGE ERROR OF ESTIMATE IS 2.8% LARGEST EoE IS 8.2% NECTARIVORES ANDS SMALL FRUGIVORES – SIX SPECIES NON-REPRODUCTIVE AVERAGE ERROR OF ESTIMATE IS 3.0% LARGEST EoE IS 7.6% LARGE OMNIVORES AND FRUGIVORES – THREE SPECIES NON-REPRODUCTIVE AVERAGE ERROR OF ESTIMATE IS 2.9% LARGEST EoE IS 6.2% SANGUINIVORES – ONE SPECIES NON-REPRODUCTIVE MALE ERROR OF ESTIMATE IS 4.0% NON-REPRODUCTIVE FEMALE ERROR OF ESTIMATE IS 12.0%

Bat FMR Modelling COMPARISON OF EMPERICAL DATA WITH MODELLED RESULTS PREGNANT FEMALES – TWO SPECIES EoE RANGE IS 2.5% TO 5.4% LACTATING FEMALES – FOUR SPECIES AVERAGE EoE IS 6.5% MAXIMUM EoE IS 25%

Bat FMR Modelling COMPARISON OF EMPERICAL DATA WITH MODELLED RESULTS

Bat FMR Modelling OBJECTIVE ACHIEVED

Bat FMR Modelling OBJECTIVE ACHIEVED Thanks: My collaborators on the various elements of the project Norman McKenzie Ariovaldo Cruz-Neto IMC 12 Organisers for the op’ to present