This book introduces the power of observation prior to, and sometimes instead of, experimental manipulation in the study of animal behaviour. It starts with simple methods suitable for student projects, before going on to demonstrate the possibilities that now exist for far more sophisticated analyses of observational data. At a time when animal welfare considerations are attracting political as well as scientific debate, the potential for non-intrusive studies on animals is being increasingly recognized. Observation emerges as a valuable alternative approach, often yielding highly informative results in situations (such as in zoos, on farms, or for wild animals) where more invasive experimental techniques would be undesirable, unethical, or just plain impossible. However, to justify its place alongside experimentation as a rigorous scientific method, observation needs to be just as disciplined and systematic, and have just as much attention paid to project design in the way that observations are made and recorded. The book travels through all these stages, from the initial observations, to the formulation of hypotheses, and their subsequent testing with further systematic observations.