Stable Isotopes to Trace Migratory Birds and to Identify Harmful Diseases: An Introductory Guide

1. INTRODUCTION 2 1.1. Background analysis 2 1.2. Migratory Birds and HPAI 5 1.3. Using SIA to understand the dissemination of HPAI - The way ahead! 7 2. ANIMAL MIGRATION TRACKING METHODS 10 2.1. Extrinsic Markers 10 2.2. Intrinsic markers 15 2.2.1. The Nitrogen Cycle 21 2.2.2. The Sulphur Cycle 22 2.2.3. The Oxygen Cycle 22 2.2.4. The Hydrogen Cycle 23 2.3. The Stable Isotopes of Water on a Spatial Scale 24 2.4. Deriving isoscapes in the absence of GNIP data 27 2.5. Use of Stable Isotopes for Migration Studies 28 2.6. Approaches for Determining Migratory Connectivity 32 2.6.1. Classification Trees to Predict Origins 38 2.6.2. Likelihood-Based Methods to Predict Origins 38 2.6.3. Migration Studies using Stable Isotopes. 39 2.6.4. Determining migratory connectivity for waterfowl in Asia 41 3. PRACTICAL CONSIDERATIONS 46 3.1. Sample Collection and Tissue Preparation 46 3.1.1. Questions of Sample Heterogeneity 48 3.1.2. Preparation of feather samples 48 3.2. Other Stable Isotopes for Migration Research 52 3.2.1. Sampling Instructions for Water d18O and d2H - Rivers / Lakes / Groundwater 52 3.2.2. Sampling Instructions for Bird Feathers for use in SIA 53 3.2.3. Sampling wild birds in the field 55 3.2.4. Sampling Strategy for H5N1 56 4. REFERENCES 60