1. Kevin Healy, Andrew Parnell & Andrew Jackson Accounting for the process of foraging in source-level variation in isotopic mixing models

2. Do Mixing models mimic ecological systems? Sources of Uncertainty Model Behaviour – Consumer sampling of food sources. Newton 2010

3. Do Mixing models mimic ecological systems? Sources of Uncertainty Model Behaviour – Consumer sampling of food sources. Newton 2010

4. Standard Error Vs. Standard Deviation Mixing Models use single draw from source distribution ~ S.D Consumers take numerous draws from source distribution ~ S.E

5. Standard Error Vs. Standard Deviation Included in SIAR mixing models using equation = Number of items eaten

6. Standard Error Vs. Standard Deviation New Caledonian Crows Rutz et al 2010 Ecological importance of tool use

7. Standard Error Vs. Standard Deviation Rutz et al 2010 Diet Proportion Larvae = 50%

8. Standard Error Vs. Standard Deviation Diet Proportion Larvae = 50% Candle Nuts = 40% Rutz et al 2010

9. Standard Error Vs. Standard Deviation Rutz et al 2010 Diet Proportion Larvae = 50% Candle Nuts = 40% Lizards = 10%

10. Standard Error Vs. Standard Deviation Simulated data Range of Items eaten (1-100) Rutz et al 2010

11. Effect of the number of items eaten on posterior credibility intervals LarvaeiNutsLizards 1 2 i5 20 100 ii1 12 5 20 100 1 2 5 20 100 Number of items Eaten Proportions 0 0. 2 0.4 0.6 0.8 1.0

12. Number of items Eaten Credability interval range (5%-95%) Effect of the number of items eaten on posterior credibility intervals

13. Number of items Eaten Credability interval range (5%-95%) Effect of the number of items eaten on posterior credibility intervals i10

14. Estimating number of items eaten using metabolic theory Estimating daily energy consumption Metabolism ~ Mass

15. Estimating daily energy consumption = Metabolic rate = Normalising constant M = Consumer mass Estimating number of items eaten using metabolic theory

16. b = daily metabolic need p = proportion of source e = energetic value of food in KJ/g a = assimilation efficiency = Mass of food source Estimating number of items eaten using metabolic theory

17. Estimation of source sampling number Crow - 300g ±1 S.D = 6.07 (White et al 2011) Rutz et al 2010 Estimating number of items eaten using metabolic theory

18. Estimation of source sampling number Rutz et al 2010 Larvae – 2.8g ± 1 S.D Nuts – 4g ± 2 S.D Lizards – 18g ± 3 S.D (Rutz et al 2007) Estimating number of items eaten using metabolic theory

19. Rutz et al (2010) Estimation of source sampling number Larvae e = 160 KJ/g Nuts e = 120 KJ/g Lizards e = 40KJ/g

20. Estimating number of items eaten using metabolic theory Rutz et al (2010) Estimation of source sampling number a = 0.75 (Castro et al 1989) Larvae e = 160 KJ/g Nuts e = 120 KJ/g Lizards e = 40KJ/g

21. Estimating number of items eaten using metabolic theory Estimation of source sampling number Rutz et al 2010 Larvae = 5.68 Nuts = 4.1 Lizards = 2.72 No. sampled over 7 days

22. Posterior proportion estimates of single Vs. multiple Items eaten

24. Acknowledgments Andrew Jackson This work was carried out as part of the Earth and Natural Sciences (ENS) Doctoral Studies Programme, funded by the Higher Education Authority (HEA) through the Programme for Research at Third Level Institutions, Cycle 5 (PRTLI-5), co-funded by the European Regional development Fund (ERDF). Andrew Parnell Mafalda Viana Luke McNally Adam Kane