What are the consequences of rapid global change for the behaviour and ecology of wild species? Answering this very broad question is a challenging but important task. One relatively manageable question under this broad umbrella is how the timing of biological events (i.e., phenology) is changing as the earth’s climate
changes. In this article, we describe a new programme aimed at assessing the timing of migration of birds that winter in the Indian Subcontinent and monitoring changes in this timing over the long term. MigrantWatch is a volunteer-based programme in which participants record the arrival, presence and departure of migrant species across India. We also outline the goals, structure, and open-access philosophy of the programme, and illustrate its potential by briefly describing information collected on the arrival patterns of winter migrants in the second half of 2007.